Sex cells- gametes divide and reproduce through a process called meiosis. The process results in four daughter cells having half the number of chromosomes as was in the parent cells. During fertilization when the sperm joins with the ovum each having half the number of chromosomes , the full chromosome number is restored. Terms used in BreedingDominant and Recessive TraitsDominant means to suppress the other. Recessive means suppressed or dominated by the other characters. If the dominant and the recessive traits are brought together, the offspring shows the dominant trait e.g. the gene for horns is dominant over the gene for hornless. Therefore if a polled bull hornless is mated with a horned cow, the offspring produced will be horned. Sometimes there is partial dominance incomplete dominance where the offspring do not resemble either parent exactly. Hybrid and Hybrid VigorAn animal is a hybrid if it possesses a dominant characteristic and the other one is recessive. If two hybrids are crossed, the offsprings will attain 75 dominance and 25 recessive ness. If two superior animals of different breeds are mated, the offspring that results is highly productive and has a higher growth rate and an improved body conformation. Such an animal has hybrid vigor or heterosis. Hybrid vigor is increased vigor and performance resulting from crossing two unrelated superior animals. The genes that produce vigor are dominant are while those that lack vigor are recessive. EpistasisIt s the combination of genes which individually could have been undesirable or inferior. This way, the effects of some recessive genes are masked such that they cannot be expressed. Breeding SystemsInbreedingOut breedingInbreedingThis is the mating of animals which are closely related to each other. Reasons for InbreedingTo increase the genetic uniformity in a herd increasing homozygosity. Fixing required characteristics in the new breeds. Increasing phenotypic uniformity. This helps to describe the external characteristics of a certain breed for example the colour of Friesians is black. Used to test whether an animal has high prepotency. To get proven sires i.e. males which have been confirmed and proven to have high qualities through backcrossing. Disadvantagesloss of hybrid vigorhigh rate of pre-natal mortalitymay lead to decline in fertility hence species extinctionSystems of InbreedingClose Breeding: this is the breeding of very closely related animals.


To get proven sires i.e. males which have been confirmed and proven to have high qualities through backcrossing. Disadvantagesloss of hybrid vigorhigh rate of pre-natal mortalitymay lead to decline in fertility hence species extinctionSystems of InbreedingClose Breeding: this is the breeding of very closely related animals. I.e. sib mating- between brothers and sisters and parent-sib mating between parents and offsprings. Line Breeding- this is the mating of distantly related animals that share a common ancestor. E.g. Cousins and cousins, granddaughters versus grand sires etc. The system aims at preserving good qualities of superior ancestors. 2 Out BreedingThis is the mating of animals that are not related. Reasons for Out BreedingTo introduce new desirable genesTo exploit heterosis hybrid vigor . A cross breed performs better than the average of the two parentsTo establish a new breed or a grade animal. Systems of Out BreedingOut crossingCross breedingUpgrading grading up Out CrossingThis is the mating of unrelated animals but within the same breed e.g. serving a Friesian cow in Nakuru with semen from a Friesian bull in Britain. The system helps to overcome weaknesses obtained through inbreeding. It also maintains the characteristics of a pure breed such as colour. Cross BreedingThis is the mating of two animals from two different breeds. This creates hybrid vigor. The system helps to upgrade the local animals by crossing them with exotic ones especially for better milk production. Upgrading or grading upThis is where the female of low grade stock is mated with a pure bred sire. The offspring gets half of the sire s genes. Such an offspring is referred to as a Hygrade. The system is commonly used in A.I to improve local cattle for milk production. Mating in Livestocka Mating in CattleOestrus Heat Period A cow comes on heat every 21 days. The duration between one hate period and the next is called oestrus cycle. Heat period in a cow lasts for 18-30 hours. The cow should betaken for service 12-18 hors after showing the first heat signs for successful mating.


The duration between one hate period and the next is called oestrus cycle. Heat period in a cow lasts for 18-30 hours. The cow should betaken for service 12-18 hors after showing the first heat signs for successful mating. Signs of HeatRestlessnessMounting others and stands still when mounted onRise in body temperatureMilk yield drops slightlyVulva swells and reddensClear slimy mucus from the vaginaBellowing and mooing frequently. B Mating in PigsSows stay on heat for 2-3 days. The best time to serve is the second day of the heat period. The sow is taken to the boar and allowed to stay there for at least 2 days. Signs of HeatRestlessnessFrequent urinationSwelling and reddening of the vulvaClear slimy mucus discharge from the vaginaFrequent mounting on othersResponds positively to the riding testc Mating in Rabbits. The does are ready for mating at 6-7 months of age. Heat signs are repeated after 14 days. Signs of heatRestlessnessFrequent urinationSwollen vulvaDoe throws itself on its sidesDoe tries to contact other rabbits in the next hutch by peepingThe doe rubs itself against the wall or any solid object. Methods of service in LivestockNatural matingArtificial Insemination A.I Embryo transplantNatural MatingThis is the use of a male to serve a female. It is commonly practiced in sheep, pigs, goats and poultry. It can also be used in cattle but AI is now commonly used. AdvantagesMore accurate. The male can detect when the female is on heat. Less laborious. There is no need of checking the animals for heat signs. Useful when the heat periods of females cannot be easily detect. DisadvantagesTransmission of breeding diseases. E.g. brucellosis and trichomoniasis. There is a high chance of inbreedingMales will need extra pasture to eat that would have been used by the females. Large males can injure small femalesA lot of semen is wasted since a single ejaculation produces semen that can serve several females. It s cumbersome and expensive to transport a bull from to serve cows.


There is a high chance of inbreedingMales will need extra pasture to eat that would have been used by the females. Large males can injure small femalesA lot of semen is wasted since a single ejaculation produces semen that can serve several females. It s cumbersome and expensive to transport a bull from to serve cows. Bulls moved from one area to another may not perform efficiently due to new environmental conditions. CannotArtificial Insemination A.I This is the introduction of semen into the female s reproductive system by hand using syringes or tube. Semen is collected from a bull using an artificial vagina and a teaser cow. Semen collected is then diluted and used to inseminate many cows. Diluted semen is stored in deep frozen state in liquid nitrogen at -1930C. Special plastic straws called Payets are used to store semen for one insemination. Payets may have different colors indicating the breed for different bulls. Collection of SemenA teaser cow is restrained in a crush. A bull is brought to the teaser cow. When the bull mounts on the cow and directs the penis to the vulva, a person grabs the penis and directs it into an artificial vagina. Since there is warm water all around the artificial vagina, the bull will ejaculate and the semen is collected. Advantages of A.ISemen from one superior bull can be used to serve many cows. It controls the spread of and transmission of breeding diseases and parasites. Sires that are too heavy and that could injure cows only produce semen to serve the cows. Easy to control breeding i.e. one can time when to breed his animals. It is easy to control inbreeding. Reduces the expenses of keeping a bull on pastures and also on drugs. Small scale farmers who cannot afford to buy a superior bull can have the cows served at a low cost. It eliminate dangerous and aggressive bulls on the farmIt is easy to transport semen from one place to another. It is a useful research tool as it helps to study a very large number of offsprings from a single sire. DisadvantagesHarmful characteristics can be spread quickly by one bull to all the offsprings the bull sires. Skilled labour is requiredRequires more human labour than the natural methodLow chances of conception because semen can die due to storage problems and also due to wrong timing of the heat period. 3.


DisadvantagesHarmful characteristics can be spread quickly by one bull to all the offsprings the bull sires. Skilled labour is requiredRequires more human labour than the natural methodLow chances of conception because semen can die due to storage problems and also due to wrong timing of the heat period. 3. Embryo TransplantIn this method eggs ova are harvested from a high quality female, fertilized in tubes and the embryos that develop are transplanted into foster mothers. The female animal that produces the ova is referred to as donor. The one that receives is called the recipient. The donor female is injected with hormones to stimulate production off more than the normal rate at ago. On superior female can produce many offsprings using this method. NB. Whereas A.I increases the number of offsprings sired by one bull, Embryo transplant increases the number of offsprings produced by one female. Advantages of Embryo TransplantPossible to implant embryo from a high quality female to a less superior female and obtain a high performing offspring. Stimulates milk production in females that were not ready to produce milk. A highly productive female can be spread over a large area to benefit many farmers. It is easier to transport embryos in test tubes than the whole animal. Embryos can be stored for long periods awaiting availability of a recipient female. DisadvantagesTechnology is expensiveRequires trained personnel to handleRequires special equipment for fertilization and storage of the embryos. Signs of parturition in:Cattle 270-285 days Pigs 4 months- 3months, 3 weeks, 3 days. RestlessnessVulva reddens and swellsUdder becomes full with a milky fluidSow builds a nest by collecting some bedding at the corner of the pen. Under normal circumstances, farrowing takes place within 4-6 hours of showing the above signs. Rabbits doe 29-33 days The doe starts building a nest by plucking off hair from her bellyLack of appetite i.e. no feeding. Parturition in rabbits is called Kindling. FISH FARMING AQUACULTURE This is the artificial rearing of fish in ponds. Importance of fish farmingCheap and good source of proteins. Can be practiced on limited land. Make fish available nearby when reared in ponds. Source of income to fish farmers.


Can be practiced on limited land. Make fish available nearby when reared in ponds. Source of income to fish farmers. Species of fish farmed in KenyaFresh warm water fish 180c of water e.g. tilapia, carps, black bass, striped bass, cat fish, blue gill, Nile perch etc. Fresh cold water fish 10-150c water such as trout. Requirements for fish farmingWater supply should be free flowing to ensure oxygen supply. Slope of land gentle slope is suitable. In flat land there is no free flow of water. Soil clay soil is best as it does not allow seepage. Soil test procedureProcedure ATake a handful of wet soil. Knead in between fingers and roll into a ribbon. Throw it into the air and catch it. If the ribbon does not break, it is truly clay. Procedure BDig a hole 1m deep by 30cm wide. Fill it with water in the evening and leave overnight, and then fill again in the morning. Good soil should retain water up to the evening of the second day. Establishing a fish pondProcedureSite selection: should meet the following;Topography ie a place where water flows gently from the source. Soil should be clayWater should be available. Security. Site marking: use pegs to mark the channel from the river, the entrance and exit and channel to take water back to the river. Clearing the land. Digging the pond: dig up soil. Topsoil is separated from the other. Upper side is 0.5m deep and lower side is 1.5m deep. Construct the dyke. This is a wall constructed round the pond. Construct the fence round the pond. Constructing the Inlet, outlet and spillwayInlet: This canal or pipe at the entrance of the pond to bring in fresh water. It should be fitted with a screen to prevent entrance of undesirable fish species. Outlet: it is made at the deeper end of the pond. A screen is fitted at the mouth of the outlet to prevent fish swimming away. Spillway: this is channel to remove excess water back to the river. It is made at the top of the dyke at the lower side of the pond. It prevents water from overflowing on the dykes. NB Grass is planted on the dyke and land around it to stabilize the ground. This prevents dyke erosion.


It prevents water from overflowing on the dykes. NB Grass is planted on the dyke and land around it to stabilize the ground. This prevents dyke erosion. The pond is fenced to keep off predators and unauthorized persons. Stocking the PondIntroduce fingerlings young-fish from hatcheries e.g. Sagana, Kiganjo, Kisumu fisheries, Bamburi etc. Transport them in oxygenated polythene bags, milk cans or drums. Provide clean water in the containers at 10 0C temperature. Take care not to injure the fingerlings. Ensure proper stocking space i.e. 5-10 fingerlings per 5m2. Feeding FishThey feed On planktonsGround nut cake, kitchen waste, slaughter house waste, leaves, grass and chicken manure. They should be given enough food. Excess foods pollute and rot the pond. Change of food should be gradual. Manure and fertilizer should be added to encourage growth of planktons. Cropping and Harvesting of FishCroppingThis is the removal of marketable size of fish from the pond. Methods used to catch fishBasketsSpears. Hook and line. Nets. DrainingAdvantages of using seine nets over hook and lineOnly marketable sizes of fish are caught. Fish are not injured in the mouth. Ensure large number of fish is cropped. HarvestingThis is the removal of all the fish from the pond by draining the pond. ProcedureThe inlet is closed stopping water inflow. Normal cropping is done using a sine net to remove all large fish. Outlet is opened to allow water to flow out. A scoop net is used to catch the fingerlings which are kept in holding pond. Water is completely drained for the pond to dry up. Maintenance of the pondRepairing the dyke or any structure on it. Cleaning the pond and remove foreign materials. Plant grass where necessary. Remove undesirable vegetation. Remove silt. Restock after 2-4 weeks by returning the fingerlings to the pond using a scoop net. Control predators. Fish PreservationPractices carried out on fish before preservationClean the fish to remove mud and worms. Remove scales and slime. Open the fish to remove the gut and intestines gutting . Clean the abdominal cavity thoroughly. Keep fish in open containers. Preservation methodsFreezing using deep freezers. Salting; use of salt solution or salt is rubbed.


Keep fish in open containers. Preservation methodsFreezing using deep freezers. Salting; use of salt solution or salt is rubbed. Sun drying: fish are spread on a mat and exposed to strong sunlight. Smoking: they are subjected to a temperature of 700C in a smoking pit house where wood is used as fuel. NB Fish are transported to the market in refrigerated containers to prevent rotting. Fish are exported or sold locally. Appropriate Handling of Livestock During Routine ManagementCarefully avoid inflicting pain on the animals e.g. avoid physical beating. Use of structures when handling animals e.g. crushes, head yoke etc. Use tools for handling e.g. ropes, halters, lead-stick and bull rings appropriately. Use correct method of securing and casting the animalUse little force when casting animals to prevent bone fracturing. Administer drugs safely e.g. by mixing them with food and water e.g. cocciodiostats. Drench carefully for example do not raise the head too high as this could choke the animal. Test equipment for giving the drug to ensure they are working such as the drenching and bolus gun. When injecting, sterilize the equipment or use fresh needles per animal to avoid infection. When spraying, spray in open air during a wind free day to avoid wind drift to unintended places or animas inhaling the chemical. NB Remove dead animals or carcasses from the herd or flock and dispose off properly through burning and disinfect the area in contact with the carcass properly. Weeds and Weed ControlA weed: Any plant growing where it is not required and whose economic disadvantages outweigh the advantages. It is a plant out of place. Or a crop that volunteers to grow without having been planted self setter . Noxious weeds: Dangerous weeds whose cultivation is prohibited by law e.g. bhang. Weeds Identification and classificationIdentificationCommon name Vernacular Botanical nameClassificationBasis:Growth cycle. Plant morphology. Habitat. Growth cycleAnnual weeds: Complete their life cycle in the field within a period of one year or less e.g. Mexican marigold, Black jack, Pig weed, etc. Annual weeds are easily controlled especially before flowering. Biennial weeds: Complete their life cycle in two years. Achieve vegetative growth in the first year and produce seeds in the second year e.g. American wild carrot, spear thistle, ragwort etc.


Biennial weeds: Complete their life cycle in two years. Achieve vegetative growth in the first year and produce seeds in the second year e.g. American wild carrot, spear thistle, ragwort etc. Perennial weeds: Take more than two years or seasons to complete their life cycle. Include: Sedges, Lantana, kikuyu grass, Wandering jew, couch grass, Sodom apple. Etc. Plant MorphologyNarrow Leaved weeds: Are grass weeds e.g. Couch, Spear, Setaria, eleusine etc. Grass weeds may be perennial or annual. Broad Leaved weeds: E.g. Black Jack, Oxalis, Lantana, Pig weeds, Devil s horse whip etc. May be annual or perennial. Competitive Ability of WeedsFactors Contributing to competitive ability of weeds:Produce large quantities of seeds. Remain viable in the soil for a long time awaiting conducive germination conditions. Some weed seeds are easily and successfully dispersed e.g. Fleabane conyza spp has developed structures used in wind dispersal. Ability to propagate vegetatively e.g. Couch grass and Wandering Jew. Elaborate and extensive rooting system. Ability to survive where there is limited nutrient supply. Short life cycle i.e. can complete their life cycle with restricted rain regime. Harmful Effects of weedsCompete with crops for nutrients, space, light, soil moisture therefore reduce crop yields. Parasitic to cultivated crops e.g. witch weed striga . Lower the quality of agricultural produce e.g. Mexican marigold gives an undesirable flavor to milk when dairy cows feed on it. Devil s horse whip, black Jack, Forget-me not, bristly fox toilet get attached to sheep wool thus lowering its quality. Some weeds are poisonous to man and livestock. E.g. Thorn apple ,Sodom apple when unripe Some act as alternate hosts for insect pests and others for diseases e.g. Black jack for Aphids, Subukia weed, Mallow, flower of the hour etc hosts cotton strainers. Oxalis, wild oats alternate rusts disease. Allelopathic: Produce poisonous substances that suppress the growth or germination of cultivated plants they contact e.g. Couch grass is allelopathic to Maize. Block irrigation channels i.e. make it difficult for water to flow freely in irrigated land. Affect fishing e.g.


Block irrigation channels i.e. make it difficult for water to flow freely in irrigated land. Affect fishing e.g. Salvinia and water hyacinth by blocking navigation and depriving fish and aquatic animals of oxygen dissolved in water. Lower quality of pastures e.g. tick berry suppress pasture undergrowth. Nut grass and Manyata grass reduce palatability of herbage and carrying capacity of pasture fields. Irritate workers thus reducing their efficiency e.g. Double thorn, stinging nettle, devil s horse whip etc. Benefits of weeds to farmersEdible to both man and livestock e.g. pig weed, wandering Jew, grass weeds etc. Medicinal effects e.g. Sodom apple, stinging nettle, sow thistle.etc. Act as soil cover, preventing soil capping due to impact of rain drops. Development of an impervious layer on the soil surface Add organic matter to the soil on decomposition. Leguminous weeds add nitrogen in the soil. Weed Control MethodsDictated by weather condition, type of weed, capital available and effects on the environment. Include;Mechanical weed control. Cultural weed control. Biological weed control. Legislative weed control. Chemical weed control. Mechanical weed controlInvolves:i Tillage cultivation Desiccate the weeds by exposing the roots to the air. Buries weeds thus killing them. Hand tools or tractor implements are used. Done during dry season to ensure better drying of weeds. Weeds are destroyed before they produce seeds to break their life cycle. Advantages of tillage in weed controlCheap and therefore good for small scale farmers. Allow infiltration of water thus minimize soil erosion. Earthing up is done during tillage which encourages root growth. Crop residue is incorporated in the soil during tillage. DisadvantagesPulverizes the soil thus destroying soil structure. Creates suitable conditions for weeds to germinate. Laborious and expensive in large scale. Leads to water loss, soil erosion and damage to crop roots. Does not effectively control perennial weeds. Ii Slashing mowing : Is the mechanical removal of shoots from weeds especially annual weeds when done repeatedly. Iii Uprooting: Done where weeds are scattered or where crops are too close to allow mechanical cultivation. Cultural weed controlAre crop husbandry practices carried out on the farm without use of chemicals. Include:i Mulching: smothers weeds thus preventing weed growth.


Iii Uprooting: Done where weeds are scattered or where crops are too close to allow mechanical cultivation. Cultural weed controlAre crop husbandry practices carried out on the farm without use of chemicals. Include:i Mulching: smothers weeds thus preventing weed growth. Ii Cover cropping; Smother the weeds. Iii Crop rotation: Weeds associated with certain crops will not germinate or grow when rotated e.g. striga in cereal crops and sugar cane. Iv Use of clean planting materials: Prevent introduction of weeds into the farm. V Proper spacing: Creates little space for weed growth or form a canopy which suppresses weeds. Vi Clean seed bed: Starts off crops on clean bed to effectively compete with weeds. Vii Flooding: Discourages growth of all non aquatic weeds. Biological weed control:Is the use of living organisms to control weeds. Include:i Use of livestock: e.g. goats in coconut and cashew nut plantations. Ii Use of certain weed eating fish to control aquatic weeds. Iii Use of Moths to control cacti. Iv Beetles to control water hyacinth. AdvantagesCheap. Not poisonous or pollute the environment. Less laborious. Does not kill soil micro-organisms. Does not destroy soil structure. Legislative weed control:-Involves government laws and acts which prevent the introduction of noxious weeds in a country or the spreading of certain weeds from one part of the country to another. Imported materials such as seeds, food and clothes are tested to certify they are weed free. Limitations:Enforcement of laws is difficult. Only sample of materials are checked while the bulk of the material may have some weeds. Noxious weed law; requires noxious weeds to be destroyed or not cultivated e.g. bhang cannabis sativa . Chemical weed control:Herbicides are the chemicals used to control weeds. Ways in which herbicides work to kill the weeds. Inhibition of nitrogen metabolism: some interfere with nucleic acids D.N.A, R.N.A e.g. Atrazines which increase or reduce nitrogen metabolism. Glyphosate interfere with enzyme functions. Kill the cell: The herbicides penetrate the cell wall, destroy it and enter cell cytoplasm, killing the cell e.g. Diquate, dinosel and oils. These are contact herbicides. Causing abnormal tissue development: Include twisting, gall formation.


Diquate, dinosel and oils. These are contact herbicides. Causing abnormal tissue development: Include twisting, gall formation. Some herbicides interfere with plant growth e.g. phenoxy acetic acids, benzoic acids, 2, 4-D and M.C.P.A. Inhibiting photosynthesis: Some herbicides interfere with chlorophyll formation e.g. Atrzines, Simazines, Duron, Linuron, and Uracils. Inhibiting Respiration: some herbicides block movement of materials from the site of manufacture to other areas. They therefore cause acute poisoning e.g. Dinozebs. Classification of herbicidesInclude:FormulationTime of application. Mode of actionEnvironmental factors. Selectivity. I FormulationIs the physical form of herbicides e.g. Liquids: are soluble in water or oils. Are highly concentrated or toxic e.g. dalapon, paraquat. Wettable powders: Finely ground particles. Form suspensions with water before application. A spreader is applied in the suspension to prevent flocculation. Constant agitation of the particles also avoids clustering. Include: atrazines, simazines and duron. Granules: Granule form. Control water weeds e.g. duron. Ii Time of application: when applied at different stages of weed growth, herbicides are effective. Include:Pre-emergence herbicides: Are applied soon after crop seeds have been sown but before they emerge. Kill the germinated weeds such that crops germinate in a weed-free environment. Include: atrazines and simazines. Post-emergence Herbicides: Are applied after crop germination or transplantation or at different stages of crop growth. Include; 2,4-D, M.C.P.A, paraquat, Glyphosate etc. Iii Mode of Action:Include:Contact Herbicides: Kill only the parts of the plant with which it comes into contact. Translocated Herbicides Systemic: Kill the whole plant even if it comes into contact with only a small part of it i.e. they are absorbed into the plant and translocated to all parts of the plant. Iv Environmental factors: Affect effectiveness of herbicides. Include:Wind: blow away splash wash to unintended places while decreasing chemical concentration to the intended places. Rain: Dilute or wash away the chemical to non-toxic levels. Leaches and reach herbicides to roots of deep rooted plants thus killing them.


Include:Wind: blow away splash wash to unintended places while decreasing chemical concentration to the intended places. Rain: Dilute or wash away the chemical to non-toxic levels. Leaches and reach herbicides to roots of deep rooted plants thus killing them. Soil: some absorb and retain more herbicides than others and therefore require more doses to be effective. Light: Increase in light intensity increases the rate of light of light absorption and photosynthesis by plants hence increasing absorption and translocation of herbicides and therefore causing faster killing of plants. Some herbicides are decomposed by high light intensity hence become less effective. Temperature: increase translocation hence absorption of more herbicides and therefore death of plants. V SelectivityInclude:Selective. Non-selective herbicides. Selective herbicide: Injures one plant and allows the other to escape injury. Selectivity of herbicides depend on susceptibility and tolerance of each plant species. Non-selective herbicide: Injures all kinds of plants because it interferes with photosynthesis. Factors Affecting Selectivity and Effectiveness of HerbicidesStage of growth of the plant: young plants are more susceptible to herbicides action because of their high growth activity. Physiological metabolic factors: beans have a poor rate of translocation of 2,4-D. maize is able to neutralize the toxic levels of 2,4-D to less toxic 2,4-B. Herbicides characteristics: Herbicides which interfere with photosynthesis are non- selective. Concentration: Under high concentration herbicides kill all kinds of plants. Formulation: Oil formulations are more toxic to plants. Method of application; High selectivity is attained by placing the herbicide where the weed is and away from the crop. Plant morphology and Anatomy:Morphological and anatomical characteristics of weeds that affect selectivity:Leaf angle: Leaf angles which are inclined e.g. grasses are less susceptible as compared to horizontal angles such as dicots. Nature of leaf surface: Plants with thick and waxy cuticles and surfaces retain less herbicides e.g. cactus, wandering jew. Differential heights of the plants: Shorter weeds than crops or shorter crops than weeds, selectivity are attained e.g. spraying weeds under coffee bushes. Location of growing points: Dicots are more susceptible to herbicides because their growing points and terminal buds are more exposed than in grasses.


Differential heights of the plants: Shorter weeds than crops or shorter crops than weeds, selectivity are attained e.g. spraying weeds under coffee bushes. Location of growing points: Dicots are more susceptible to herbicides because their growing points and terminal buds are more exposed than in grasses. Difference in rooting system: Shallow rooted plants are more susceptible to herbicides than deep rooted which require herbicides with long residue effect. Specialized structures: Plants with underground structures such as rhizomes and bulbs e.g. sedges and oxalis are not easily killed by herbicides. Safety Precautions in Use of ChemicalsRead manufacturer s instructions. Wear protective clothing e.g. overall, breathing masks, gloves, and boots. Avoid inhaling herbicide i.e. not spray against wind, not smoke and wear a breathing mask. Bath thoroughly after handling the chemical and not eat before bathing. Do not unblock blocked nozzles by blowing with the mouth. Avoid spraying against the wind not spray on windy days. Avoid spilling herbicides on pastures and fodder crops. Dispose of empty containers and left overs e.g. by burying them. Do not wash spraying equipment in water sources used by livestock and humans. Store chemicals out of reach of children and away from food. Wash equipment thoroughly. Advantages of using HerbicidesRequire less labour than mechanical cultivation. Adapted to control of bothersome weeds e.g. Couch grass and sedges. Does not disturb crop roots and underground structures. Makes control of weeds in certain crops easier e.g. wheat, burley, carrots. Efficient in both wet and dry soil conditions as compared to mechanical cultivation. Maintains soil structure. ,Convenient to use in certain crops e.g. sisal and sugarcane and weeds such as double thorn and stinging nettle which injure farmers. Cheaper than manual or mechanical cultivation on large scale farming . DisadvantagesRequire skilled labour in mixing and application. Poisonous to environment and the user. Some herbicides have long residue effects pollutes environment . Expensive Uneconomical in small scale. Revision questionsWhat is a weed? Name two poisonous weeds. State 5 harmful effects of weeds to farm crops. State 5 methods of controlling weeds. Give 5 factors that affect selectivity and effectiveness of herbicides. State 4 problems encountered when using herbicides in the farm. How does crop rotation control weeds? State three beneficial effects of weeds.


State 4 problems encountered when using herbicides in the farm. How does crop rotation control weeds? State three beneficial effects of weeds. Classify herbicides. State 5 ways in which herbicides work to kill weeds. State 3 factors that determine the rate of herbicide application. A What name is given to the chemicals used to control weeds? B Explain the correct procedure for mixing gramoxone in a sprayer for weed control. 13. Explain any 4 factors contributing to the competitive ability of weeds. 14. State 3 characteristics of annual weeds. 15. State 4 effects of water hyacinth attack. 16. State 3 limitations of mechanical weed control method. 17. Explain any 4 cultural methods of weed control in a field of maize. 18. Describe the classification of herbicides on the basis of formulation. 19. A Name 4 biological agents used in weed control. B State 2 advantages of biological wed control. 20. State 3 factors which make herbicides cause crop injury or poor weed control. 21. State 4 factors to consider when choosing a method of weed control. GRAZING SYSTEMSThere are three main grazing systemsRotational grazingContinuous grazingZero grazing1 Rotational GrazingThis refers to practice of allowing livestock to feed on a part of pasture for a period down to certain level before they are moved to the next. This gives time for pasture to properly regenerate. Advantages of Rotational GrazingLivestock make maximum use of pastureReduces the build up of parasites and diseases. Animal waste is distributed evenly in all fields paddocks. Pasture area is given time to re-grow before its grazed on again. Excess pasture can be harvested for conservationIts possible to apply fertilizers in parts of the pastures are not in useIt facilitates reseeding and weeding. The methods of rotational grazing include paddocking, strip grazing and tethering. A PaddockingA paddock is a fenced portion of a pasture in which animals are restricted for grazing. Paddocking means grazing livestock in one paddock for a short period and then moving to another. The size of the paddocks depends on the carrying capacity of the pasture. There should be a watering point at each paddock. A water trough is placed between two paddocks so that animals can drink water from either paddock. Paddocking saves herding labour.


There should be a watering point at each paddock. A water trough is placed between two paddocks so that animals can drink water from either paddock. Paddocking saves herding labour. However, it is very expensive to construct. B Strip GrazingDone by allowing livestock to graze on restricted portion of the pasture at a time then moving them to the next. It s done on very high quality pastures. Electric fences can be used to enclose animals in a given strip of pasture. Where animals are not many herding may be done to restrict them to stay within the strips. Temporary fences may also be used instead of the electric fences. However, the system is quite expensive. C Tethering-This involves tying the animal to a post with a rope such that it feeds within a restricted area. -The rope may also have a metal ring that slides along a strong wire supported by strong poles. 2 Continuous Grazing Herding In this type of grazing, the pasture is not allowed any resting period. This method can easily result in overgrazing if the stocking rate is not controlled. It s common in the semi-arid areas. 3 Zero Grazing Stall Feeding -This is the practice of rearing animals in a permanent feeding enclosure known as the stall. Feed is cut and taken to the animals in the stalls. -They are also provided with plenty of clean water and mineral licks. AdvantagesThere is quick accumulation of manureAnimals make use of the feeds without wastageAnimals produce high yields due to less wastage of energy. It s easy to control diseases and parasitesIt requires little landIt allows higher stocking rateDisadvantagesHigh initial capital is requiredHigh management skills are neededNeed a lot of labourDiseases can easily spread. REVISION QUIZUse of lethal temperature. Suffocation. This is used in the Cyprus bins where CO2 is introduced to suffocate pests. Flooding. This can be used c to control pests such as armyworms and cutworms. Moles can also be killed through flooding. Proper drying of the produce. This makes grains hard for pests to penetrate and discourages the3 growth of moulds. Grains should be dried up to a moisture content of 12 Physical destruction of pests. Hand picking and trapping can be used to control pests. Use of scarecrows.


Grains should be dried up to a moisture content of 12 Physical destruction of pests. Hand picking and trapping can be used to control pests. Use of scarecrows. They scare large animals and birds out of the farm. Use of physical barriers. They include use of fences to control large animals and rat proofing in stores. Use of electromagnetic radiation. Some wavelengths of electromagnetic radiations can be used to deactivate enzymes in some insect pests. Some pests are attracted by certain wavelengths such as moths are attracted by ultra-violet rays and aphids by yellow light. Once attracted, heat or chemicals can then be used to destroy them. X-rays can also be used to control some storage pests. 3. Cultural Methods. This is the use of all the good farming practices to minimise and discourage pests from attacking the crops. Cultural practices do not eradicate or kill pets but alter the environment for pest s survival and discourage pest attack. These practices include the following. Tillage. This exposes soil borne pests to their natural enemies or exposes them to the hot sun, which kills them. Weed control. Some weeds act as alternative hosts to crop pests. Removal of such weeds reduces pest infestation. Early planting. This enables crops to establish earlier before pests multiply to large numbers. Burning of crop residue. This destroys pests and their eggs reducing further attack on the next crop. Crop rotation. This interferes with the life cycle of pests reducing their populationUse of clean planting materials. This ensures that no pests or their eggs are introduced into the field. Planting resistant crop varieties. E.g. goose necked sorghum reduces attack by birds. Closed season. This is where a particular crop is not grown for a season to control a particular pest such a not growing maize to control maize stalk bores. Crop nutrition application of fertilizer. This encourages vigorous and healthy growth of crops, which can tolerate and escape pest attack. Pruning. This discourages conditions, which may favour the breeding grounds of pests in crops. Timely harvesting. Crops can be harvested at the right time to avoid pest attack e.g. overripe fruits encourage attack by fruit flies. Proper spacing. This discourages quick spread of pests. Growing of trap crop. This is the growing of a crop to trap certain crop pests either before or at the same time with the main crop. Irrigation. Overhead irrigation controls aphids in cabbages. 4. Chemical Control. This involves the use of pesticides to control pests.


4. Chemical Control. This involves the use of pesticides to control pests. Pesticides influence the pets in three ways. By direct poisoning. By inhaling. By ingesting. The pesticide used should beEfficientSelectiveCheapPersistentSafe to the user and the environment. Classification of PesticidesFormulation. E.g. soluble powders, wettable powders, fumigants, dust, liquids, granules, emulsions etc. Target pest. InsescticidesNematocidesRodenticides. Fungicides. Mode of action. They may be classified according to the way they function into the following. Stomach poisons. These only kill those pests, which consume the sprayed crop with the chemical, hence are selective. Systemic poisons. They are circulated to all parts of the pest once it has eaten the sprayed part of a plant. Contact poisons. They kill the pests when they are absorbed in the body through the skin or cuticle. They are not selective and may kill many beneficial organisms such as predators, pollinators, decomposers, birds etc. Suffocants. They kill by interfering with the breathing system after being inhaled. Anti-feedants. They inhibit feeding on insects and other pests thus starving them to death. Repellants. They keep the pest away from the plant. Factors affecting the Efficiency of PesticidesConcentration. Correct concentration should be used when diluting the pesticide, as it is the most effective. Timing of Application. They should be applied at the stage of development when the pest is most susceptible to the pesticide. Weather conditions at the Time of application. If the rain falls immediately after application of a pesticide, it may wash off or dilute the pesticide thereby reducing its effectiveness. Persistence. If a pesticide can remain effective for long, then the better. This ensures that more pests can be controlled. Advantages of Chemical ControlMethod is faster compared to other methods such as crop rotation, field hygiene etc. Most pesticides have rapid knock-down effect hence the method is more reliable and predictable. DisadvantagesExpensive. Most are not environmental friendly since they are toxic to man and livestockThey require care and skill when handling and applying them. Most are non-selective and therefore they kill useful insects such as pollinators and predators. Pests establish resistance to pesticides if they are used continuously against them. E.g. DDT. 5.


E.g. DDT. 5. Biological Pest ControlThis involves the use of a living organism, which is a natural enemy of the pest. The method is environmental friendly but it can be very slow. Crop Diseases And Their ControlDiseaseIt is a condition that interferes, impairs or disturbs the normal performance of an organism. A disease is a deviation from good health. Harmful Effects of Crop DiseasesLowers crop yield. Poor quality products hence reduced market value. They cause food poisoning by producing toxic substances such as Aspergillus flavus in maize produces Afflatoxin; Ergot in wheat and barley causes nerve endings. Increase the cost of production. Classification of Plant DiseasesFungal diseasesViral diseasesBacterial diseasesNutritional diseases deficiency Other causes. 1. Fungal DiseasesThey are either parasitic or saprophytic. This gives rise to the following categories. Obligate parasitic fungi. They completely depend on other living organisms for food. They are found in plant parts such as leaves, roots, stems, fruits etc. Facultative parasitic fungi. They can live on both the living and dead tissues. Saprophytic fungi. They live as decomposers on dead decaying plant and animal remains. They are beneficial in nutrient recycling. Parasitic fungi are grouped into three:Those with all the mycelia vegetative part and the fruiting bodies on the surface of the host such as Erysiphe spp, which causes mildews. Those with the mycelia inside the plant tissues but the fruiting bodies on the surface of the host such asPhytophthora infestans. Late blight in tomatoes and potatoesPuccinia spp. Rusts. Ustillago spp. Headsmut. Those having the mycelia and fruiting bodies all inside the host. E.g. Fusarium spp causing Fusarium wilts. Examples of Fungal1.Late BlightCaused by Phytophthora infestans .the disease affects most members of the solanaceae family such as Irish potatoes and tomatoes. The fungi are parasitic and feeds by sending short hyphae called haustoria into the cells of the host. Haustoria absorb plant nutrients manufactured food from the plant cells resulting in the death of the cell. The fungi reproduce by spore formation, which are dispersed by wind and raindrops.


The fungi are parasitic and feeds by sending short hyphae called haustoria into the cells of the host. Haustoria absorb plant nutrients manufactured food from the plant cells resulting in the death of the cell. The fungi reproduce by spore formation, which are dispersed by wind and raindrops. It spreads very quickly during warm moist conditions. SymptomsRapid drying of the leaves forming dry patches necrotic lesions on leaves and fruits. Affected fruits appear rotten and fall off prematurely. ControlSpraying with Bordeaux mixture and other copper based fungicides. 2. RustsCause Puccinia spp. They attack the leaves and stems of most cereal crops. P. Sorghi - sorghumP. graminis. MaizeSymptomsInfected leaves have red to brown pustules hence reduced photosynthetic are and low yields. Crops appear rusty. ControlSpraying with Bordeaux mixture and other copper based fungicides3. SmutsCause Ustillago spp. U. scitiminea sugar caneU. nuda - wheatU. maidis- Maize. This produces large number of black spores, which forms black masses on maize tassels and maize cob. ControlHot water treatment of the seeds. Use of certified seedsCrop rotation. Field hygiene e.g. rogueing and proper disposal of previous crop residue. 4. Coffee Berry Disease CBD Cause Colletotricum coffeanum. It attacks the flowers, leaves and berries. Flowers and leaves have dark brown spots. Spots on leaves develop along the margin and later spread to the rest of the leaf causing defoliation. The disease attacks both green and ripe berries. Attacked green berries fail to form beans and are hollow. Attacked ripe berries have sunken wounds and are difficult to pulp process. ControlSpraying with appropriate copper based fungicides. Open pruning. Resistant varieties e.g. Ruiru 11. Other Fungal DiseasesDamping off. Pythium spp. Powdery mildew. Root rots Armillaria spp. Downey mildew Peranospara spp. Early blight Alternaria spp. Anthracnose Colletotricum lindemuthianum2. Viral DiseasesAll viruses are parasitic and very small. They are only able to reproduce and multiply in living tissues.


Anthracnose Colletotricum lindemuthianum2. Viral DiseasesAll viruses are parasitic and very small. They are only able to reproduce and multiply in living tissues. When outside living tissues, they form spores in cysts, which remain inactive until they get into a living tissue. They are therefore obligate parasites. Viral infections interfere with important life processes of plant such as photosynthesis, respiration, transpiration, and nitrogen utilisation. Symptoms of Viral infectionsLeaf chlorosis loss of chlorophyll. Leaf curling. Mosaics production of light green patches on leaves. Malformations distortions of plant parts e.g. galls swellings , small leaves etc. Rosetting production of abnormally short nodes hence stunting. NB Insect vectors such as aphids and mealy bug transmit viral diseases. Infected vegetative parts such as sugar cane cuttings also transmit viral diseases. Examples of Viral diseasesMaize streak. Formation of white yellow stripes on leaves parallel to midrib. Greening disease attacks leaves of citrus. Tristeza attacks citrus trees. The leaves fall off and there is dying of twigs. Cassava mosaic -Brown streak of cassavaPotato leaf rollTobaccoGroundnut rosette. Viral diseases are controlled by controlling the vectors. C. Bacterial DiseasesBacteria are facultative parasites. They are single celled and microscopic. Not all bacteria are harmful. Some are beneficial to man e.g. Rhizobium spp which is a nitrogen fixing bacteria. They may be transmitted through insects, wind, raindrop splashes, manures, seeds, irrigation water, cultivation implements and pruning knives. They enter plants through openings such as stomata, lenticels and wounds. Symptoms of Bacterial DiseasesWilting even when water is in adequate amount due to blockage of xylems. Cankers results into the death of plant tissues. Gall formation in the infected tissues. I Bacterial Blight of Coffee BBC Cause Pseudomonas syringe. Bacteria enter plant through wounds and natural openings. It s common in areas experiencing hailstorms. SymptomsDark necrotic lesions with water soaked margins on affected parts. Shoot die back. Cankers on mature bark and wood killing the whole plant. ControlSpraying chemical eg.


Shoot die back. Cankers on mature bark and wood killing the whole plant. ControlSpraying chemical eg. Supanil, before, during and after the flowering periods especially during the wet weather. Bacterial wilt Pseudomonas solanacearum Attack potatoes, tomatoes and other solanaceae plantsAffected plants wilt even when the soil is moist. Leaves droop and plants eventually dieHigh temperature accompanied by wet conditions favour the disease. Black arm of cottonBlack rot of cabbageHalo blight of beansNutritional disordersWhen crops do not get enough nutrients, deficiency symptoms appear egYellowing of leavesDrying of leavesFalling of leaves, flowers and fruitsStunted growthDeath. E OTHER CAUSESFlooding. During flooding ammonia may be formed. Since ammonia is toxic, it has burning effect to plants. ChemicalToxic chemical compounds in the soil may be absorbed by the plants leading to death of the plant eg. Cyanides. Poor weather. Extreme day and night temperature may be injurious to the crop. Eg very cold temperature causes frost injury in tea. StressStressful conditions on the plant such as irregular watering may causes physiological disorders such as blossom end rot in tomatoes. Control of crop diseasesCultural methodsThis involves the use of crop husbandry practices that discourages the outbreak of diseases without the use of chemicals. They include;Planting resistant crop varieties that can withstand the effect of certain diseases without lowering the yields eg Ruiru II is a coffee variety resistant to CBD. Practicing proper spacing of crop. Overcrowding results to quick spread of diseases. Use of health planting materials. Some diseases are seed borne and can effectively be controlled by use of artificial seeds for planting. Practicing field hygiene eg burning of crop residue destroying infected plants etc. Drying of cereals and pulses to a moisture content of 12 13 before storage. This discourages attack by moulds fungi Heat treatments of some planting materials eg treating sugar cane cutting with water at 500c for 30 minutes control ratoon stunting disease effectively. Proper pruning of crop destroys the micro- climate that may have encouraged build up of diseases causing organisms. Chemical controlChemical control should be practised only when all other methods have proved to be ineffective and when it s economical.


This discourages attack by moulds fungi Heat treatments of some planting materials eg treating sugar cane cutting with water at 500c for 30 minutes control ratoon stunting disease effectively. Proper pruning of crop destroys the micro- climate that may have encouraged build up of diseases causing organisms. Chemical controlChemical control should be practised only when all other methods have proved to be ineffective and when it s economical. Chemical control measures include:Seed dressingThis is the application of fungicides before planting seeds. The fungicides prevent attack on the planted seeds. SprayingThis is the application of chemical such as fungicides using a sprayer. Soil fumigation. This is the application of chemical fumigants in the soil. The chemical are usually in dust or granule form and are mixed with the soil to kill soil borne diseases causing organisms in the soil eg in the control of Bacterial wilt in potatoes. Advantage of chemicalsChemical act faster in controlling diseases. Effective Chemical requires less labour in application. Disadvantages of chemicalsExpensiveRequires skills in applicationToxic to humans and livestockPollutes environmentSome do not break down easilyc .Legislative methodThis involves imposing of regulations and laws in cases of diseases outbreaks to prevent the introduction and spreading of diseases. REVISION QUESTIONS1 Below is a diagram of a bird which is a crop pest. I Identify the bird mk ii State two ways by which the bird causes loss in crops. 1mk iii State four methods which are used to control the pest. 2mks 2. Study the diagram below and answer the questions that follow. A Identify the fungal disease indicated above b State the causal organism of the disease identified above 1mk c State two symptoms of the disease above lmk d State one control measure for the disease in the control field lmk 3.The diagram below shows a kale seedling attacked by a pest.


1mk iii State four methods which are used to control the pest. 2mks 2. Study the diagram below and answer the questions that follow. A Identify the fungal disease indicated above b State the causal organism of the disease identified above 1mk c State two symptoms of the disease above lmk d State one control measure for the disease in the control field lmk 3.The diagram below shows a kale seedling attacked by a pest. A Identify the pest. 1mk b What damage does the pest cause to the crop? 1mk c State one method of controlling the pest. 1mk d Name two other insect pests other than the one identified in a above that attack kale in the field. 2mks 4.Describe the physical and cultural measures employed in the control of pests in crop production. 20 marks 5. Given the pest shown in the diagram belowName the barrier you would put on a grain store to control the pestApart from the use of barriers list four other physical methods of pest control in and out store. 2mks 6 a Identify farm storage pests shown below 1 mks b Name crop products attacked by each of the above pests 1 mks c Name one chemical control of the above pests mk 7. Define the following terms as used in crop pests and diseases; 2mks a Economic Injury Level. EIL b Integrated Pest Management IPM 8. Below is an illustration of a maize cob attacked by smut disease. Study: it carefully and answer thequestions that follow:a Beside w hat is visible on the maize cob. State two other symptoms of the disease. 2mks b State three control measures of the above disease. 3mks 9. Study the crop pest illustrated below. A Identify the crop pest. 1mk b State two effects of the above pest. 1mk c State three methods of controlling the pests. 3mks 10 Describe the methods of disease control in crops under the following headings.


1mk b State two effects of the above pest. 1mk c State three methods of controlling the pests. 3mks 10 Describe the methods of disease control in crops under the following headings. Cultural methods 14 Marks Chemical methods 6 Marks 11 The diagram below represents crop pests a Identify the pest ... mk b Name Two crops that are attacked by the above pests 1mk c Give three control measures 1 mks ANSWERS1. I Identify-A-Weaver bird 1x mkii 2 ways bird causes damagei Eats grass2 Causes the grains to fall off3 Exposes maize cobs to rain leading to rotting4 Strips the leaves 2x 1mk 2. A Blight 1x mk b phytophthora infestans 1x1 1 mk - fruits rot and fall prematurely-Brown lesions on stems, leaves and fruits 2x 1 mk d Spraying using fungicides Bordeaux mixture lx1 mk 3.a -Cut worm . 1 x 1 1mk b Cuts the stem of seedlings 1 x 1 1mk c -Application of appropriate pesticide dust soil with aldrin and rake into soil. 1 x 1 1mk d i Aphidsii Sawfly. 2 x 1 2mks 4.Physical and cultural measures employed in control of pests in crop productionPhysical methodsPhysical destruction of pests which involve hand picking or trapping and killing them eg moles in the gardenFlooding-some pests like cut worms and army worms will be drawn if flooded. Flooding may be used to kill underground pests like molesProper drying of the produce-drying of grains make them hard for pests to break and penetrate hence discouraging the growth of mould. Grains should be dried to moisture content of about 11-13 moisture contentUse of electromagnetic radiation-certain wavelength of electromagnetic radiation like radioactive.


I Identify-A-Weaver bird 1x mkii 2 ways bird causes damagei Eats grass2 Causes the grains to fall off3 Exposes maize cobs to rain leading to rotting4 Strips the leaves 2x 1mk 2. A Blight 1x mk b phytophthora infestans 1x1 1 mk - fruits rot and fall prematurely-Brown lesions on stems, leaves and fruits 2x 1 mk d Spraying using fungicides Bordeaux mixture lx1 mk 3.a -Cut worm . 1 x 1 1mk b Cuts the stem of seedlings 1 x 1 1mk c -Application of appropriate pesticide dust soil with aldrin and rake into soil. 1 x 1 1mk d i Aphidsii Sawfly. 2 x 1 2mks 4.Physical and cultural measures employed in control of pests in crop productionPhysical methodsPhysical destruction of pests which involve hand picking or trapping and killing them eg moles in the gardenFlooding-some pests like cut worms and army worms will be drawn if flooded. Flooding may be used to kill underground pests like molesProper drying of the produce-drying of grains make them hard for pests to break and penetrate hence discouraging the growth of mould. Grains should be dried to moisture content of about 11-13 moisture contentUse of electromagnetic radiation-certain wavelength of electromagnetic radiation like radioactive. Radiation may be used to deactivate enzymes in some insects and pestsUse of lethal temperature-this involves the use of extreme temperatures either too cold or too hot conditions to control pests by inhibiting their survival i.e. use of hot water to control pink ball wormUse of physical barriers-this include use of materials that prevent pests from getting to the crop i.e. rat guard metal plates on posts of raised granaries.


Radiation may be used to deactivate enzymes in some insects and pestsUse of lethal temperature-this involves the use of extreme temperatures either too cold or too hot conditions to control pests by inhibiting their survival i.e. use of hot water to control pink ball wormUse of physical barriers-this include use of materials that prevent pests from getting to the crop i.e. rat guard metal plates on posts of raised granaries. Construction of fences around the field and trenches to control large animalsSuffocation-has been used in Hermetic Cyprus bins where build up of carbon iv oxide is used to suffocate pestsUse of scarecrows-are used in scaring large animals and birds out of the farmCultural methodClosed season-the period in which a susceptible crop is not grown in order to control a certain pest or group of pests. During this period crop residues are collected and disposed off to ensure destruction of the pest. Timely planting-early planting of crops are more likely to escape pest attack than late planted ones eg maize stalk borersTimely harvesting- some storage pests like grain weevils attack the crop while in the field therefore early harvesting will enable the crop escape the attackProper tillage- field cultivation will expose the pests which are soil borne like white grubs. The pest is exposed and scorched by the sun or eaten by birds and other predatorsPlanting resistant crop varieties-plant breeders have developed plants which have natural protective mechanisms against pest attack i.e Goose necked sorghum against birdsField hygiene- this means keeping the field free from any plant materials harbouring pests i.e. Rogueing and removal of crop residues from the fieldAlteration of environmental conditions-creations of certain micro-climate that is not conducive to some insects i.e. open pruning in coffee to discourage antestia bugs, mulching reduces thripsTrap cropping-a crop which is planted before or together with the main crop purposely for attracting away from the main crops. The pest is then killed by either spraying with chemicals, ploughing the crop or rogueing. Crop rotation-crops which are more preferred by a particular pest are rotated with those that are not or less preferred i.e. groundnuts and potatoes that control nematodes. This starves the pest to death. Destruction of alternative hosts-some weeds act as alternative host to crop pests.


Groundnuts and potatoes that control nematodes. This starves the pest to death. Destruction of alternative hosts-some weeds act as alternative host to crop pests. The removal of such weeds reduces pest infestationCrop nutrition- application of fertilizers and manure makes the crops to grow strong and be able to resist and escape attack. Use of clean planting materials- this prevent introduction and spreading of crop pests. Seeds, suckers and crowns should be free from pestsProper spacing- proper spacing makes it difficult for pests to move from plants to plant while close spacing in groundnuts discourage AphidsUse of organic manure-FYM, compost manure has been found to discourage various pests ie eel wormsIrrigation-overhead irrigation is able to control Aphids in cabbages20x1 20 marks6. A Identify farm storage pests shown below. A Maize weevil b Bean weevil bean bruchid Flour weevil. B Name crop products attacked by each of the above pests. A Maize wheat barley sorghum grains; b Bean bonavist bean butter bean seeds; Maize wheat barley sorghum millet flour c Name one chemical control of the above pests. Use of actellic powder on dry grains and seeds of maize and beansRespectively primiphos-methy organophosphate. 1 2 mark it is the level at which the tolerance of a plant has been exceeded. 1mk It is the combination of many methods to effectively control pests. 1mk 8 a -Severe dwarfness-Increased tillering b -Planting resistant varieties-Use of certified seeds-Field hygiene-Crop rotation9 a -Maize weevil b -Makes tunnels beneath the seed coat-Make circular holes on the surface of the grain c -Dusting maize cob with malaltion-Fumigate maize with methyl bromide-Proper storage hygiene-Ensure grains are stored at correct moisture content10 a Cultural methods of crop disease control. Using healthy planting materials to prevent the crops from being infected by seed borne diseases. Practicing field hygiene such as a burning crop residue using clean implements, clean weeding to destroy micro-habitat for diseases. Proper seedbed preparation e.g. Control of root rot disease.


Practicing field hygiene such as a burning crop residue using clean implements, clean weeding to destroy micro-habitat for diseases. Proper seedbed preparation e.g. Control of root rot disease. Proper spacing to control dumping off diseases especially in nursery bed. Heat treatment to control ratoon stunting disease in sugar cane. Proper drying of cereals and pulses for proper storage. Use of disease resistant varieties e.g. Ruiru II, Resistant to CBDAny 7, 1 for mentioning and 1 for explaining 7 x 2 14 marksb Chemical disease control in cropsThrough seed dressing application of fungicides on seeds before planting. Sol fumigation application of fumigants in soil to control soil borne diseases. Spraying application of fungicides insecticides. Any three 1 for mentioning and 1 for explaining 3 x 2 6 marksFORM FOUR AGRICULTURE NOTESLIVESTOCK PRODUCTION V POULTRY PRODUCTION IntroductionThe term poultry refers to all kinds of domestic birds kept for meat or eggs production. They include turkeys, ducks, geese, guinea fowls, chicken, ostriches and pigeons. The management of poultry aims at production of high quality eggs and meat to meet the ever increasing market demand. Selection and BreedingSmall scale farmers increase their flock by keeping breeds that go broody. However commercial poultry farmers buy day old chicks from recognized hatcheries such as Kenchic and Muguku. Hybrids are not recommended for breeding as their hybrid vigour would decline in their offspring and many do not go broody. Broodiness is the desire to sit on the eggs. The birds selected should have the following characteristics. YoungHealthyAble to go broodyProlificGood mothering ability. Commercial farmers should also consider the following. Whether the enterprise is for meat or egg productionAge, that is either day-old or at point of laying. Breed of birds in respect to egg colour and size of birds. Production, which is percentage laying or growth rate. NB . After the selection of the breeding stock, cocks are allowed to run with hens daily to ensure that all the eggs are fertilisedComposition of an EggThe parts of an egg include the following. The shellThe shell membraneAir spaceEgg white albumen ChalazaeYolk.


NB . After the selection of the breeding stock, cocks are allowed to run with hens daily to ensure that all the eggs are fertilisedComposition of an EggThe parts of an egg include the following. The shellThe shell membraneAir spaceEgg white albumen ChalazaeYolk. The shellIt forms about 10-12 of the total egg content and is largely made up of calcium and phosphorous compounds which make it hard. It gives the egg its shape and provides protection to the inner contents of the egg. The egg shell is porous and allows gaseous exchange to take place. This makes it possible for the embryo to develop. Shell membraneThis forms the inner lining of the shell and makes about 1 of the egg content. It is formed of two separate membranes which closely adhere to each other. The two membranes separate at the broad end to form an air space air cell. The inner membrane is about 0.015mm thick and the outer one is about 0.05mm thick. The air in the air space is used by the developing embryo during incubation. Albumen Egg whiteThe albumen forms about 55-60 of the total egg content. It is a jelly like colourless fluid when fresh and turns white when cooked. It is divided into four major parts: chalazae and chalaziferous albumen, thin inner albumen, thick albumen and outer thin albumen. The albumen surrounds the yolk and serves as a food reserve to the developing embryo. It is mainly protein. ChalazaeThis forms about 3 of the albumen and it s a dense white mass floating all over the place within an egg. It has two twisted cords which hold the yolk in place at the centre of the egg. The two chalazae hold the yolk from both ends of the egg thus allowing the yolk to move the germinal disc always to the top position. This is important during incubation for the purpose of heat transfer to the developing embryo. If the chalazae are broken the yolk is displaced from its normal position. The YolkIt is divided into three major parts and forms about 33 of the total egg content. It is yellow in colour and spherical. Its main function is to supply for all the embryo requirements since it contains food reserves for the developing chick.


The YolkIt is divided into three major parts and forms about 33 of the total egg content. It is yellow in colour and spherical. Its main function is to supply for all the embryo requirements since it contains food reserves for the developing chick. The yolk is rich in vitamins, fats, minerals and proteins. The three parts are:Germinal discPigmentsVitelline membrane. The germinal disc: this is formed from the ovary after fertilization and is always found at the top of the yolk as a small spot regardless of what position an egg is resting. The disc is joined to the centre of the yolk by a funnel shaped structure called the streak latebra. This allows maximum heat transfer to the developing embryo within the yolk. The egg pigments: The pigment contained in the yolk always comes from the food the bird eats and also from its body. This pigment is known as Xanthophylls and is responsible for the colour of the shell and that of the yolk yellow The vitelline membrane: the vitelline membrane surrounds the yolk and therefore gives the yolk its shape. If the egg is not properly stored, this membrane may break up causing the yolk to come out of it. Incubation of eggsThis refers to the embryonic development of a fertilized into a chick under correct conditions which will ensure that a chick is hatched from the egg. In chicken these conditions must be provided for 21 days while in turkeys and ducks this takes 28 days. Selection and Care of Eggs for IncubationEggs for incubation should have the following characteristics. Should be fertilizedMedium sized-55-60gm in weight. Lighter or heavier weight lowers hatchability. Have smooth shellOval in shapeFree of any cracks in the shellClean to ensure that the pores are openNot have abnormalities such as blood spots, meat spots or double yolkShould be fresh collected within one week and not more than 10 days. NB . The internal condition of the egg is examined through egg candling. Egg CandlingThis is the method used to check the freshness of an egg for physical abnormalities or likelihood of being hatched. It is done by passing a strong light through the egg in a dark room. The source of light may either be a torch, candle or electric bulb.


Egg CandlingThis is the method used to check the freshness of an egg for physical abnormalities or likelihood of being hatched. It is done by passing a strong light through the egg in a dark room. The source of light may either be a torch, candle or electric bulb. Procedure of candlingThe egg is pace over a hole made on a card board box. A light under the box is then put on. The observer then looks at the egg against the light below. The following can be observed through egg candling. The size of the air spaceIf the egg is fertilised the germinal disc will be seen as a black spot . Whether the yolk has blood spots. Whether the shell has cracksWhether the egg shell is brokenWhether the shell is very porous. Incubated eggs are candled two or more times. First candling is done between the 5th and 7th to check for fertility. If they are fertile, blood veins are seen. If they are not they appear clear. The second candling is done on the 18th day to confirm the presence of the chick. An egg with a living embryo clearly shows a large section containing the embryo and a smaller section which is clear containing the air space. Methods of IncubationNatural incubationThis method involves the use of a broody hen to sit on the eggs. The hen provides the necessary conditions for incubation e.g. warmth, turning the eggs etc. The hen must sit on the eggs for 21 days for successful embryonic development. A hen normally shows some signs when it is about to go broody. Signs of Broodiness in PoultryProlonged moultingTendency to sit on the eggs after layingNumber of eggs laid are fewPlucking of feathers from the abdomen breast regionProduces a characteristic sound and becomes aggressive. Preparation and Management of Natural IncubationEnsure the hen is completely broody. I.e. shows the ability to sit on the eggs for long hours. The broodiness can also be induced by use of China clays. Prepare the nest in a secluded place of the poultry house. The nest can be a wooden box, karai, a woven basket or a carton box. The nesting box should be spacious to allowmovement of the hen.


Prepare the nest in a secluded place of the poultry house. The nest can be a wooden box, karai, a woven basket or a carton box. The nesting box should be spacious to allowmovement of the hen. The nest should be lined with some nesting materials such as dry grass, sawdust or wood shavings to maintain warmth in the nest. Give an adequate number of eggs to the broody hen i.e.10-15eggs. A hen may not cover more than 15 eggs hence low hatchability. Set the eggs in the evening or night but not in the morning so that the chicks will start emerging on the evening or night of the 21st day. When the chicks start emerging in the morning, the hen will walk out with a few chicks and leave the un-hatched ones to die. Regularly dust the hen with appropriate pesticides so as to control external parasites such as fleas, mites etc. Allow the bird to occasionally move out to scratch and exercise. Feed the brooding hen daily and provide adequate clean water. NB . The hen should not be disturbed at all. Advantages of Natural IncubationLess skill is requiredIt is not labour intensive as there is no turning of the eggs and checking of temperatures. It s a cheap way of multiplying birds i.e. small scale farmers who cannot afford incubators can multiply their flocks using this method. Hatchability is very high compared to artificial incubation therefore reducing the risk margin. DisadvantagesOnly few chicks can be hatched at a time by one henEgg production is reduced when the birds go broody. It s only possible with breeds that go broody. The farmer cannot plan when to incubate. Diseases and parasites can easily be transmitted to the chicks from the hen if it is infected. 2. Artificial IncubationUnder this method all the conditions necessary for the hatching of the eggs are provided artificially by equipment called an incubator. Conditions Necessary for Artificial IncubationTemperature: Temperature should be maintained at 37.5oC 39.4oC. Lower or higher temperature would kill the developing embryo. Fresh Air Ventilation: There should be adequate fresh air circulating in the incubator. The fresh air is required by the developing embryos. Ventilation facilitates gaseous exchange and helps to control humidity. Relative Humidity: It should be about 60 . If it is too low, the embryos may lose moisture and die.


Ventilation facilitates gaseous exchange and helps to control humidity. Relative Humidity: It should be about 60 . If it is too low, the embryos may lose moisture and die. Water is placed in a tray within the incubator to maintain the humidity. The damp cloth also assists in maintaining the relative humidity. High humidity lowers hatchability and leads to production of large chicks which look abnormal. It also results into dampness which predisposes the eggs to infections. Egg Turning: This is quite important in the management of an artificial incubator. This helps to avoid the germinal disc sticking onto the egg shell leading to the death of the embryo. Wrong turning of the egg may lead to breaking of the blood vessels. Turning should always be done along the axis of the eggs and each time in a different direction. Some incubators have automatic turning devices. Management of the IncubatorThe following should be observed for artificial incubation. The incubator should be cleaned and disinfected or fumigated before putting in the eggs. Eggs should be turned every 6-8 hours each day. However in the first 24 hours and the last three days they should not be turned. These are the critical stages of embryonic development. They should be turned around 180oC. Any egg found to be infertile on the 5th day should be removed. Remove any broken eggs. Maintain temperature within the set rangeAdd water as necessary to maintain the correct humidity. Advantages of Artificial IncubationIt s possible to plan when to have the chicks. Many chicks are hatched at onceIf management is good, there is no danger of infecting the chicks with diseases and parasites. The incubator is usually ready when required. Egg production is not affected by incubation as the hens do not go broody. DisadvantagesIncubator is expensive to buy hence has high capital investment. More labour intensive. More skills requiredHave high risks of damaging all the eggs if the requirements such as temperature or relative humidity are not strictly observed and controlled. Only viable in large scale hatcheries. Sources of ChicksFor success in the poultry enterprise, the following factors should be put into consideration. Reputation of the supplierThe type of chicks required in relation to size, breed, sex etcTime factor i.e. how long the chicks will take in transit from the hatchery to the farm. Very long hours of transportation cause stress to the chicks.


Reputation of the supplierThe type of chicks required in relation to size, breed, sex etcTime factor i.e. how long the chicks will take in transit from the hatchery to the farm. Very long hours of transportation cause stress to the chicks. Arrangement should be made to feed the chicks on transit if the source is very far. The most reputable sources of chicks in Kenya are;Muguku Poultry Farm- Kikuyu. Lake Chicks Hatcheries KisumuKenchic Hatcheries Athi riverStockplan Hatcheries MombasaSigma Supplies NairobiKen Bird NairobiBrooding and Rearing of ChicksBrooding is the rearing of chicks from one day old to the time they are taken to the main house. Brooding is a very critical and difficult period in the management of birds. There are two methods used in brooding the chicks. Natural BroodingArtificial Brooding. Natural BroodingThis follows natural incubation. The hen is allowed to provide warmth and other requirements to the chicks. Feed and water should be provided for both the hen and the chicks. The hen stays with the chicks until they are old enough to feed themselves. AdvantagesIt is cheapIt is suitable for most small poultry farmers. It is less labour intensiveDisadvantagesOnly possible where the hens go broodyIt is not suitable for large scale production of birds. Lowers the egg production during the brooding period. Artificial BroodingThis refers to keeping of the chicks in a structure called a Brooder where food and other requirements are provided. Chicks remain in the brooder for 6-8 weeks. Requirements in an Artificial BrooderLitter: this should be in the form of wood shavings. This should be on the floor. It maintains warmth and absorbs moisture. Fresh air: holes for ventilation should be made on the walls of the brooder for gaseous exchange. The holes however should not allow draught into the brooder. Heat source: there should a wire guard round the heat source to prevent the chicks from being burnt. Correct temperature should be maintained at 32-35oC in the first week, 29-33oC in the second week and 26-300C in the third week. The heat sources include electric bulbs, charcoal burners, lantern, kerosene and gas burners. The heat source should be withdrawn gradually to avoid stress.


Correct temperature should be maintained at 32-35oC in the first week, 29-33oC in the second week and 26-300C in the third week. The heat sources include electric bulbs, charcoal burners, lantern, kerosene and gas burners. The heat source should be withdrawn gradually to avoid stress. If it were withdrawn at once, the chicks would overcrowd at one point of the brooder resulting in deaths. A thermometer should be used to check the temperature. The behaviour of the chicks can also be used to tell whether the temperature is correct. When the chicks move away from the heat source then the temperature is too high, while overcrowding around the heat source means the temperature is too low. When the temperature is optimum the chicks are found evenly spread all over the brooder floor. The brooder should have sufficient lighting to allow the chicks to see water and food. Very bright light makes the chicks toes to shine hen toe pecking and also makes the chicks blind. Dim light is therefore recommended. Shape of the brooder. There should be no sharp corners in the brooder. Such corners would encourage overcrowding hence suffocation of the chicks. EquipmentFeeder: There should be sufficient feeders for the chicks. If the chicks overcrowd during feeding then more feeders should be made available. The feeders should be kept clean. During feeding the chicks should be given a feeding allowance of 1 inch per chick during week 1-2 and 2 inches per chick from weeks 3-6. The feeders should have a rotating bar to avoid the chicks contaminating the feed by stepping or defecating on the feed. Waterers: The waterers should also be made in such a way that the chicks do not defaecate or step into the water. They should be pointed at the top so that the chicks cannot perch. They should always be kept clean. During the first to second week the appropriate spacing for the waterers should be 0.2 inches per chick and 0.4 inches per chick from week 3 to week 8. Brooder and Brooder Managementa Preparation before the chicks arrives. The brooder should be made ready 2-3 days before arrival of the chicks. The brooder house should be washed and disinfected. Spread litter then cover it with newspapers. Newspapers help to prevent the chicks from eating the litter. Place water and feed equipment in the brooder house. Ensure they are clean.


Newspapers help to prevent the chicks from eating the litter. Place water and feed equipment in the brooder house. Ensure they are clean. Place food in the feeders and water in the waterers. Provide heat source in the brooder. Check to ensure the heat source is functional. Turn on the heat source on the day of chicks arrival. B Day of arrival of chicks. Vaccinate them if they were not vaccinated in the hatchery. Remove any dead chicks and dispose off properly. C FeedingRemove the newspapers after the chicks have learnt to eat from the feed troughs. Provide chick mash till the eighth week. Chick mash has 20-22 DCP and vitamins A and D. it is highly digestible. Ensure the chicks are given adequate amounts of feeds at all times. In the sixth week introduce grit or sand to help in digestion. Also introduce roosts for the chicks to perch. In the seventh week, introduce growers mash. Start with growers mash mixed with chick mash at a ratio of 3:1 respectively. Gradually reduce the amount of chick mash as the amount of growers mash is increased. When the chicks are 8 weeks old, they are removed from the brooder. At the ninth week, chicks are fed on growers mash only and are now taken to the main poultry house. Clean the troughs and waterers daily. Provide adequate clean water daily. NB . On average a chick uses 1.5-2.2 kg of chick mash during the brooding period of 8 weeks. D Parasite and disease controlVaccinate chicks against Gumboro after 2 weeks, Newcastle, 3-4 weeks and fowl typhoid at 7 weeks of age. Dust chicks with appropriate pesticides such as pyrethrins to control external parasites e.g. mites, lice etc. Provide antibiotics mixed in chick mash or drinking water to protect against disease attacks e.g. coccidiostats are incorporated in drinking water to control coccidiosis. Isolate and treat sick chicksDispose off dead chicks properlyDisinfect the feeders and waterers. Provide a footbath at the entrance of the poultry house. E Other management practices. Debeaking should be done 8-10 days towards the end of the brooding period. Keep proper records of the feeding programme, treatment and the number of deaths of the chicks.


E Other management practices. Debeaking should be done 8-10 days towards the end of the brooding period. Keep proper records of the feeding programme, treatment and the number of deaths of the chicks. Management of Growers 9th week-20th week i.e. point of lay From the 9th week the birds are referred to as growers or pullets. A FeedingFeed the growers on 115 grams of growers mash per bird per day. Growers mash contains 16-17 crude protein, vitamins and mineral salts. Supplement the growers mash with grains and greens. Hang the greens to provide exercise for the birds. Introduce layers mash from the 16th week and increase gradually. At the 12th week onwards soluble grit should be provided. This provides enough calcium which is necessary for hard egg shell formation. Provide clean water ad libitum. B Parasite and disease control. At the 18th week vaccinate against fowl pox. Give a booster vaccine against Newcastle disease at 20 weeks of age. Drench the birds regularly against internal parasites. Dust the birds with appropriate pesticides against pests such as fleas, mites and lice. Control predatorsClean and disinfect waterers and feeders daily. C Other management practices. Provide more floor space for the birds as compared to when they were in the brooder. Keep litter as dry as possible by turning it regularly or scattering grains on it to facilitate turning of the litter by the birds. NB. Birds start laying at 18-21 weeks of age depending on the breed. Light breeds begin to lay at 18-20 weeks, some hybrids start laying at 18 weeks while indigenous breeds begin to lay at 23-27 weeks. Feeding and Rearing of LayersProvide enough floor space, roosts, feeders, and waterersGive each hen about 120 grams of layers mash per day. The layers mash contains 14-16 DCP, Vitamins A, B, C and minerals. Provide clean water alwaysVaccinate every 6 months against Newcastle and fowl typhoidKeep the litter as dry as possible. Provide enough laying nests in the poultry house. Collect eggs twice, noon and eveningHang green leaves to keep the birds busy preventing cannibalismIncorporate grains at the rate of 65 grams per bird per day.


Provide clean water alwaysVaccinate every 6 months against Newcastle and fowl typhoidKeep the litter as dry as possible. Provide enough laying nests in the poultry house. Collect eggs twice, noon and eveningHang green leaves to keep the birds busy preventing cannibalismIncorporate grains at the rate of 65 grams per bird per day. Cull non layers and cannibalsProvide soluble grit or oyster shells all times to ensure strong shelled eggs and efficient digestion. Feeding and Rearing of BroilersBroilers are referred to as table birds. They are kept for meat production. They exhibit high growth rate and have a very high feed conversion ration. They usually achieve a weight of 2kg in about 60 days. The following practices are carried out. FeedingChicks kept for broiler production are fed on broiler starter mash. The feed contains 20-24 DCP, vitamins and minerals essential for rapid growth. Provide adequate clean water alwaysFrom week 4-5 gradually introduce broiler follow on mash or pellets. It contains 18-20 DCP. It encourages development of lean meat i.e. discourages over fattening. The feed should be provided ad libitum. From 8th week up to slaughter the birds are given broiler finisher pellets. Parasite and disease controlDe-worm regularlyDust the birds to control external parasitesVaccinate against common disease e.g. Newcastle disease at 3rd-4th weeksIncorporate coccidiostats in the broilers pellets. Dispose off dead birds properly. C HousingBroilers are best managed under the deep litter system. Its floor space requirements are low, about one square foot per bird. The house should be well ventilated for efficient air circulation. Broilers should be kept in dimly lit houses to reduce their activity, ensuring that most of the feed taken in is used for growth. Rearing SystemsThe method of keeping poultry is referred to as rearing system. The choice of the system to use depends on the following factors. Land availabilityLabour availabilityCapitalSecurityMarketAvailability of appropriate equipmentTopography of the land to facilitate easy drainageKnowledge of the farmer. There are four main rearing systems i.e.


The choice of the system to use depends on the following factors. Land availabilityLabour availabilityCapitalSecurityMarketAvailability of appropriate equipmentTopography of the land to facilitate easy drainageKnowledge of the farmer. There are four main rearing systems i.e. Free rangeFold systemDeep litterBattery cage system1 Free Range Extensive systemBirds are allowed to move freely in a fenced ground that has a house to provide shelter at night and during the rainy seasons. The laying nests are also put in the house. Feed and water troughs are placed outside but should be protected against rain. RequirementsLand. Should be adequate, well drained and with trees for shade. It should be fenced. About 100 birds should be kept in 1 acre. Runs. The land should be partitioned to allow rotation. This reduces diseases and parasite build up. The partitioned areas are called runs. House. The house should be movable or at the centre of the runs. AdvantagesCannibalism and egg eating are reduced as the birds are not overcrowded. Birds exercise hence good growthNo need to provide grit as the birds can pick it from the groundLess feed is used as the birds supplement with insects and grass. Manure is evenly spread in the runs hence vegetation regenerationIt requires low capital investmentLow labour requirement. DisadvantagesA lot of land is needed for the birdsBirds can be eaten by predators or stolenEggs get lost in the runsDirty eggsDifficulty in close supervision of individual birdsBreeding programme not easily followedIf the perimeter fence is not adequate the birds can damage crops on the farm. The range area may become contaminated with diseases and parasites2 Fold System Semi Intensive System. This is a system where birds freely eat vegetation but are confined in small houses called folds or arks. A fold system measures 3.5m long, 1.5m wide and 1.5m high. Such a fold can accommodate 10-15 birds. 1 3 of the fold is roofed to provide shelter and the rest is open but enclosed by chicken wire mesh. The unroofed part allows sunlight and is used for exercise and feeding on the grass. The folds should be moved to a new ground daily. This reduces pest and disease build up, provides fresh grass to the birds and avoids accumulation of droppings.


The unroofed part allows sunlight and is used for exercise and feeding on the grass. The folds should be moved to a new ground daily. This reduces pest and disease build up, provides fresh grass to the birds and avoids accumulation of droppings. AdvantagesManure is uniformly spread in the fieldLess feeding costs since the birds supplement the feed with insects and grassThere is no need of fencingReduced pest and disease build up. DisadvantagesFolds don t last long due to too much handlingFew birds are kept per foldVery laboriousEgg production records per bird are difficult to keepThe returns per unit land are relatively low. 3 Deep Litter System. This is an intensive system. In this system, birds are confined within a big house. Requirements of a deep litter systemi SiteThe land should be well drained. Ii HouseShould be leak proofThe leeward side should be open from 60-90cm above the ground. This area should be covered with a wire mesh. The floor should have litter. The litter keeps the floor warm and absorbs moisture. Litter materials include crushed maize combs, coffee husks, sawdust, wood shavings etc. The litter should be 15-30cm deep. Litter should be turned regularly to mix the droppings. Grains should be thrown regularly on the litter for the birds to scratch for the grains thus turning the litter. The floor space requirement should be 1m2 per 2- 3 birds. Iii Feeders and WaterersThey should be enough and should always be cleaned daily to avoid any infections. Iv Roosts and PerchesRoosts are timber frames on which the birds perch for rest. They should about 30cm per bird and should be about 1-1.2m. They should be movable for easy removal of droppings and for easy cleaning. Diagramsv Laying NestsProvide laying nests in the poultry house. Requirements for laying nestsShould be dimly lit to discourage egg eatingLarge enough to accommodate the bird comfortably. Nests are of two types, individual type and communal type. Individual type should measure 25-30cm wide, 30-35cm high and 30-36cm long.


Requirements for laying nestsShould be dimly lit to discourage egg eatingLarge enough to accommodate the bird comfortably. Nests are of two types, individual type and communal type. Individual type should measure 25-30cm wide, 30-35cm high and 30-36cm long. Communal nests can accommodate 50-60 birds and they measure 1.35m 1.5m long, 30cm wide and 35cm high on the front side and 75cm on the back side. It should have a door measuring 20x20 cm wide. Place dry clean beddingsAdvantages of the deep litter systemHigh stocking rateSystem can be used for rearing a breeding stockFast accumulation of manureBirds are safe from predators and thievesLess loss of eggsLow labour requirements once everything is in place. DisadvantagesThere is a likelihood of pest and disease accumulation in the litterCannibalism, egg eating, feather plucking and toe pecking are common. Individual egg production record is not possibleLitter may be difficult to find in some areasFeeders and waterers may be contaminated by litter if not properly placedEggs may become dirty if they are laid on the floor or if the laying nests are not clean. MILK AND MILKINGMilkWhite substance secreted in the mammary glands of female animals. It is secreted as food for their young ones. It is also processed into products such as butter, cheese and ghee. Composition of milkThe composition of milk varies from one animal to another as shown below. It contains proteins, carbohydrates lactose fats, minerals and water. Factors affecting the milk compositionAge of the animal; young animals produce milk with high butter fat content than old animals. Physiological Condition of the animal; under conditions such as extreme emaciation, the butter fat content significantly drops. Pregnant animals also produce milk low in butter fat content. Completeness of milking; the last milk to be drawn has the highest butter fat content. Also the milk drawn form animal in the evening has higher butterfat content as compared to that obtained in the morning. Stage of lactation and pregnancy; butterfat content, proteins and minerals in milk are usually higher at the middle of the lactation period and drop towards late gestation.


Completeness of milking; the last milk to be drawn has the highest butter fat content. Also the milk drawn form animal in the evening has higher butterfat content as compared to that obtained in the morning. Stage of lactation and pregnancy; butterfat content, proteins and minerals in milk are usually higher at the middle of the lactation period and drop towards late gestation. Type of food eaten by the animal; animals eating a lot of roughages produce milk rich in fats, proteins and lactose than animals which is fed on a lot of grains. This is because roughages produce a lot of acetic acid a volatile fatty acid which is used as a source of energy in the mammary glands to synthesize milk . Breed differences; different breeds produce milk wit5h different percentage composition as shown below. Season of the year; fats increase during the cold season. The solids not fats decrease during the hot season. Other factors animals under treatment produce milk of variable composition depending on the drugs used. Animals suffering from mastitis have reduced lactose because the mastitis bacteria attack the milk sugars. Milk Secretion and Let-downThe structure of the mammary glandIt is the organ responsible for milk production in mammalian animals. It is composed of balloon shaped secretory cells called alveoli alveolus . The alveoli are surrounded by a dense network of blood capillaries. These alveoli are joined together by a capsule to form a lobule with a duct. The alveoli drain their content into the lobule. Several lobules are grouped together to form a lobe which is drained by the lactiferous duct. Many lobes form one quarter of the udder. Several lactiferous ducts drain into the gland cistern of the quarter. The quarters of the udder are anatomically separated and drain into separate te4at cisterns. Each teat has an opening called a teat orifice canal whose opening and closing is controlled by the a sphincter muscle. Milk secretionMilk is made from products of digestion such as blood sugar, amino acids and fatty acids. These nutrients are carried by blood into the alveoli where they are manufactured into lactose, casein and butter. Other milk components such as vitamins and minerals are also added to milk through filtration by the alveoli cells. Milk synthesis or lactogenesis is controlled by the hormone prolactin.


These nutrients are carried by blood into the alveoli where they are manufactured into lactose, casein and butter. Other milk components such as vitamins and minerals are also added to milk through filtration by the alveoli cells. Milk synthesis or lactogenesis is controlled by the hormone prolactin. Low levels of oestrogen during late gestation period stimulate the secretion of the hormone prolactin by the pituitary gland. Prolactin activates milk secretion process in the mammary glands. Milk secreted is stored in the hollow cavities of the alveoli and within the lactiferous ducts. Some milk however drains into the gland cistern where it is stored until milking. Milk let downThis is the flow of milk from the upper region of the udder alveolar region to the lower part of the udder gland cistern and teat cistern . This process of milk let down is caused by the hormone oxytocin released by the pituitary gland. Oxytocin causes contraction of the muscle fibres surrounding the alveoli. This contraction forces milk into the gland and teat cisterns. However some external factors also influence the milk let down process. These are:Taking the cow into the milking shedSight or smell of food in the feed troughRattling sound of the bucketsSight of the milkmanMassaging or washing the udder with warm waterSight of the calf for cows used to suckling calvesSuckling by the calfNB. Milk let down lasts for about seven to eight minutes hence the person milking must be very fast in order to remove as much milk as possible. Proper stimulation of the udder when milking is therefore very necessary throughout the milking process. The secretion of adrenaline from the adrenal glands suppresses the effects of oxytocin. Adrenaline inhibits the supply of blood to the alveolar region causing relaxation of the muscles fibres thus there is no milk let down. Other factors that may contribute to inhibition of milk let down include;Excitement or frightening of the cow. HungerChange of milkmanChange of the milking scheduleEffects of the oestrusFeeling of painStrange surroundingsBefore milking the alveolar cells are turgid but after milking they appear long and thin.


Adrenaline inhibits the supply of blood to the alveolar region causing relaxation of the muscles fibres thus there is no milk let down. Other factors that may contribute to inhibition of milk let down include;Excitement or frightening of the cow. HungerChange of milkmanChange of the milking scheduleEffects of the oestrusFeeling of painStrange surroundingsBefore milking the alveolar cells are turgid but after milking they appear long and thin. Clean milk productionCharacteristics of clean and high quality milkFree from disease causing organismsHas no hair, dirt or dustHas high keeping qualityHas a good flavourIts chemical composition is within the expected standardsEssentials of clean milk productionAvoid flavours in milk- bad flavours in milk are caused by feedstuffs and oxidation. Silage and feedstuffs such as Mexican marigold, onions and other fruit wastes can cause bad flavours in milk. Such feedstuffs should be given to the animals after and not before or during milking. Oxidation of milk fats occurs when milk has been exposed to the sun for a long time or if put in containers with traces of copper or iron giving it a bad flavour. Milk should therefore be protected from sunlight and should be stored in containers which are free from of traces of copper or iron. Healthy milking herd. Cows should be tested regularly for milk borne diseases such as tuberculosis and brucellosis. A strip cup should always be used to check for mastitis. Clean milking cows. The flanks, underline and the whole udder should be washed and dried thoroughly before each milking. Two towels should be used. One for cleaning the udder and the other one for drying. Any long hair on the udder and flanks should be clipped. Healthy and clean milkman. Any milkman suffering from contagious diseases should not handle milk or do the milking. The milkman should keep his finger nails short and should have his hair covered. He should preferably wear an overall when milking. Clean milking shed. The milking parlour should be kept clean. It should have a good drainage and easy to clean. It should be cleaned after every milking. Clean milking utensils. The milking utensils and equipment should be seamless and smooth to facilitate thorough cleaning. They should be washed with hot water and detergent. Keeping them in the sun during the day sterilises them.