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Senior Four Agriculture FARM STRUCTURES Farm structures are physical constructions put up on the farm to facilitate the production process. …


Senior Four Agriculture

FARM STRUCTURES Farm structures are physical constructions put up on the farm to facilitate the production process. Examples of farm structures include;
  • Buildings;(stores, offices, animal houses).
  • Water storage structures (dams, boreholes, tanks and reservoirs)
  • Fences (barbed wire fence, plain wire, wooven wire fence, electric fence, trench fence and live fence)
  • Animal handling structures (spay races, cattle dips, crushes).
FENCES: A fence is a barrier made out of some wood, metal stakes, nails or wires and living plants for the purpose of keeping animals from straying or keeping intruders out of the farm. IMPORTANCE OF FENCES ON THE FARM
  • Fences provide privacy and security to the farm i.e. keep out trespassers and thieves.
  • Fences help to demarcate the farm boundaries hence avoiding land disputes with neighbours.
  • Fences can facilitate rotational grazing on the farm by dividing the farm into paddocks.
  • Fences are used in controlling breeding by reducing inbreeding and random mating as males can be kept away from the females.
  • Fences make it easier to practice mixed farming by protecting crops from animals.
  • Double fencing is very effective in controlling ticks and other internal worms on the farm.
  • Live fences can act as wind breaks hence controlling wind erosion and destruction of farm structures.
  • A network of fences add beauty to the farm.
  • Fences can increase the value of the farm since they are assets.
  • Fences make it easier to regulate the water supply by distributing water troughs in the various paddocks.
  • Fences reduce the labour requirement as animals can be left to graze on their own.
  • Availability of capital; with enough capital, fences like electric fences can be used.
  • Topography; hilly areas may not favour trench and concrete fences since they can be damaged.
  • Animals to be confined; small livestock such as goats, sheep and poultry can be confined in woven fence but not on barbed wire.
  • Fences enable grouping of animals according to their age, making feeding easier or confines livestock in paddocks.
  • Skills of the farmer; highly sophisticated fences like electric fence can only be handled by skilled people.
  • Farmers’ interest; some fences may be highly preferred by the farmer hence used on the farm.
  • Maintenance costs; fence with high maintenance cost are least preferred by the farmers.
TYPES OF FENCES: LIVE FENCE; this is made of living plants, trees and shrubs planted in rows to form a hedge that is thick enough to prevent penetration by animals or intruders. The common shrubs used in making live fences are; Kei apple, sisal, tick berry milk plants euphorbia spp etc.Udemy style 15 ADVANTAGES OF LIVE FENCES:
  • Planting materials can be obtained locally hence cheap.
  • Little maintenance is needed once plants have established.
  • When they are mature they help to conserve soil and water by acting as wind breaks.
  • Thorny species like Kei apple, sisal effectively discourage intruders and trespassers.
  • Live fences can last for a long period of time if well managed.
  • If well planted and managed live fences can give a pleasant look of the farm.
  • The pruned branches and leaves can provide supplementary source of food to animals.
  • Live fences may take many years to grow and make an effective fence.
  • The growth of live fences may be irregular leaving some gaps which appear only later to allow both animals, thieves and intruders to pass through easily.
  • Hedges without thorns create good hiding places for thieves, wild animals and vermin.
  • Hedges require regular triming and gap filling which is both labourious and expensive.
  • Hedges may compete with crops for nutrients.
  • Some hedge plants are poisonous to animals.
  • Some hedges harbour pests that attack both animals and crops.
  • Live fences can not be used effectively to sub divide land into paddocks for grazing.
  • Some varieties of hedges like Kei apple may be dangerous to farm animals, man and his transport systems like bicycles.
  • Select a desirable plant species and obtain the planting seeds. They should be free from pests, diseases and viable.
  • Clear the area and dig out any perennial weeds within the reach of one meter.
  • Make planting holes large enough and in straight lines depending on the land boundaries.
  • Sow the seeds in the holes and cover with top soil mixed with manure.
  • Keep watering the seeds until they have germinated.
  • Carry out gap filling and thinning after germination of seedlings.
  • Control weeds frequently to reduce weed competition with seedlings for growth factors.
  • Control pests and diseases to enable the hedge to grow vigorously.
  • Pruning should start at an early stage to encourage lateral growth which helps to remove all gaps in the fence.
  • Regular pruning to control height and to allow lateral branches.
  • Regular spraying with pesticides and fungicides to control pests and diseases which affect the growth of the hedge.
  • Gap filling by re-planting with new plants.
  • Regular weeding to reduce competition for growth factors and to encourage vigorous growth.
  • Control of fire destruction by clearing the vegetation around the hedge one meter (1m) wide.
  • Pass 2 to 3 strands of barbed wire in non-thorn hedges to discourage the attempts by the animals to break through.
BARBED WIRE AND POST FENCES: This is made up of barbed wires tightly stretched and supported upright on posts that are well set on the ground. The wire is fixed onto poles by means of staples which are U-shaped. The commonly used posts are made of wood, metal and concrete. The wire is tightened using a wire strainer.Udemy style 16 EQUIPMENTS FOR A BARBED WIRE FENCE;
  • Posts; wood, metal or concrete.
  • Wire; barbed wire or plain wire.
  • Staple nails or U-nails.
  • Wire strainer.
  • Hammer, hand saw, measuring tape and a pair of pliers.
STRAINER/CORNER POST; this is the biggest of all the posts. It is normally fixed at the corners and gates. Strainers are always braced with struts to resist the strain of the pull of wires. STANDARD OR ORDINARY POST; this is a medium post used everywhere to hold the wire except at the corners and gates. Standards experience less strain since the wire pulls them in both directions. DROPPER; this is long thin piece of wood which are usually woven upright between the posts. Droppers reduce wire sag and discourage any animal that may try to push itself through the fence. STRUT; this is a post fixed on the corner post and into the ground to support the corner post. BRACE POST; this is the first post after the corner post. PROCEDURE OF CONSTRUCTING A BARBED WIRE FENCE:
  • Determine the area on the ground where the fence line is to pass.
  • Clear the land where the fence line is to pass to a width of about two meters to allow ample working space and ensure it is right land to be fenced.
  • Locate the corners where the corner posts are to be fixed.
  • Dig holes at the corners and along the corners using a straight line.
  • Fix the corner posts.
  • Using the recommended spacing, mark out the sites where the holes for gate posts, foot path should be fixed.
  • Nail struts to the corner posts and gate posts.
  • Fix standards.
  • Fix the wire starting from the lower one, the number of strands will depend on the docility of the animals to be contained.
  • Droppers are then fitted in between the standard posts.
  • The fence is less attacked by termites and fire.
  • The fence can last for long especially if wooden posts are treated or if the posts are metal or concrete.
  • Wire fences do not compete with crops for growth requirements as in live tree fencing.
  • Wire fences do not become hosts for pests and diseases.  Wire fences can be established easily/quickly.
  • It is easy to establish.
  • Requires skill to establish it.
  • Barbed wire can damage the hides and skins of animals.
  CALCULATIONS INVOLVING FENCES  Teso College Aloet school farm has a rectangular piece of land measuring 1500 meters by 600 meters around which a four-strand perimeter barbed wire fence is to be constructed. Given that the length of the barbed wire roll is 600 meters and the spacing between the fence posts is 5 meters and no gate should be provided, calculate;
  1. The number of fence posts required to fence the farm.


Establish first the perimeter of the farm land. Perimeter = 2 (length + width) P       = 2(1500 +600) = 3000 + 1200


But, the spacing between the poles is 5 meters, Therefore, the number of poles  =       perimeter of the land Spacing between posts No. of poles                               =        4200      + 1 5

                                                   =       841 poles

  1. The number of rolls of wire required to fence the farm land.
No. of rolls =        perimeter of farm land x No. of strands
                    Size of the roll of wire.
=   4200 x 4           = 16800
        600                      600

                               =      28 rolls of wire

  1. The number of staples required to fence the farm land.
Solution; No. of staples         =        No of poles x No of strands =       841 x 4

                             =       3364 staples

  1. If the cost of one roll of barbed wire is 60,000 shs. Calculate the total cost on barbed wire. Solution;
Total cost of barbed wire = No. of rolls x cost of rolls
= 28 x 60000
Total cost of barbed wire = 1,680,000=
ELECTRIC FENCES: These are movable fences made of posts, insulators, fencing wire and a 6 Volt battery or source of electricity. When in operation, any animal that touches the fence gets a shock though not enough to harm it. ADVANTAGES OF ELECTRIC FENCE:
  • It is suitable of strip grazing.
  • Can easily be relocated to another area.
  • It is very effective in protecting crops from big wild animals.  Reduces labour requirement.
  • It is very expensive to establish/maintain.
  • Requires reliable power source.
  • Unapproved electric controller units can be dangerous.
  • It requires skills to install.
  • Continuous shocks frighten the animals reducing their productivity.
TOPIC: ANIMAL HANDLING LAYOUTS These are structures used when handling farm animals for specific purposes. The handling layouts include;
  • The Crush.
  • The Plunge Dip/ Dip tank.
  • Spray race.
  • Handling yards.
THE CRUSH: A crush is a structure used for enclosing/restraining animals during routine husbandry practices.Udemy style 17 Operations that can be carried out in a crush include;
  • Vaccination
  • Deworming/drenching
  • Castration
  • Taking blood samples
  • Milking
  • Foot triming
  • Hand spraying or hand dressing of ticks
  • Weighing of animals
  • Artificial insemination
  • Dehorning
  • Branding /identification
  • Close examination of sick animals
  • Pregnancy tests
  • It should be made up of sliding bars at the entrance to hold the animal back while in the crush.
  • It should be made up of steel pipes or wooden posts.
  • It should have a gate for exit.
  • It should have entrance for the animal to enter into the crush.
  • It should have head yoke to hold or fix the head.
It should share dimensions 2meters long, 1.5 meters wide and 0.75 meters wide. TYPES OF CRUSHES
  1. Three -post crush; this is used when restraining one animal. It has an entrance and is enclosed at the other end.
Diagram of a three-post crush:
  1. A continuous / variable length crush; this is used when handling many animals. It is made of two parallel fences. It is made in such a way that its narrow at the bottom and wide at the top or it may be vertical from top to bottom. It can be as long as is convenient for the operation to be carried out.
  • A crush can be used for a variety of operations.
  • It is constructed using locally available materials
  • There is no risk of loss in milk production or condition of animals due to trekking to far off communal dips.
  • The farmer can properly control the strength of the acaricide.
  • No risk of animals collecting or spreading diseases at the communal dip.
  • Can be used to spray both sick and pregnant animals.
It can help in operations like milking, vaccination, Artificial insemination that can not be done in a dip. DISADVANTAGES OF CRUSHES:
  • It is not durable unless it is made out of steel posts and rails.
  • It is not convenient for handling so many animals in operations like spraying.
  • The animal may not be covered well with acaricide.
  • Crushes waste acaricide since it is not reused. Ø Crushes may not be able handle calves.
  A PLUNGE DIP / DIP TANK. A dip tank is a structure used to control ticks by total submergence of the animals in the acaricides.Udemy style 18 CHARACTERISTICS OF A GOOD CATTLE DIP.
  • The collecting yard should have adequate space for holding cattle.
  • The collecting yard should be made of concrete for easy cleaning.
  • The entrance race should be made of concrete to reduce the amount of dung /dirt carried on feet into the dip tank.
  • The entrance race to the dip tank should have a slanting jumping point, to allow easy jumping into the dip tank.
  • It should have a cut-walk / side walk for the farmer to guide animals through, across the dip wash.
  • The footbath should be filled with adequate clean water to remove dirt and dung from the feet of animals.
  • The drainage race should be slopping backwards to allow the acaricide to flow back into the dip tank.
  • The drainage race should be long enough to allow the acaricide to drain from the animals.
  • The cattle dip should have walls made of concrete with no cracks to avoid loss of acaricide through seepage.
  • The dip should have a leak-proof roof to avoid dilution by rain water and reduce evaporation.
  • The exit ramp/steps should have gentle slopes to allow the animals move out of the dip tank easily.
  • It should have a concrete floor /rough surface from the collecting yard to the drainage race to avoid sliding of animalsThe dip tank should have adequate capacity to hold enough dip wash to cover the animals.
The return pipe should be slopping towards the dip tank to allow excess acaricide to flow back in the dip tank.
  • Should have a soak-away pit to allow proper disposal of used acaricide.
  • The drainage pipe should slope outside to divert rain water from entering dip tank.
  • It should have a sump which collects and filters the acaricide from the drainage race before it is returned to the tank.
  • Do not dip sick animals because they can collapse inside the dip.
  • Pregnant animals and small animals should not be dipped for they can get injured.
  • Do not dip on a rainy day because the acaricide can be washed a way before it sticks properly.
  • Dipping should be done during cool hours of the day to avoid absorption of the acaricide by dilated veins of the animals.
  • Animals should not be dipped when they are thirsty because they can be tempted to drink the acaricide.
  • Ensure correct level of the dip wash in the tank.
  • Ensure correct concentration of the acaricide in the dip tank.
  • Ensure there is enough water/disinfectant in the foot bath.
  • Ensure the acaricide is uniformly mixed before dipping.
  • Ensure the roof is leakproof/not leaking.
  • Replenish the dip wash regularly.
Assemble the animals in the colleting yard.
  • Allow the animals to drink water before dipping starts.
  • Check the level and concentration of the dip wash and replenish if necessary.
  • Fill up the footbath with clean water.
  • Open the pipe that returns the dip wash from the drainage race to the tank.
  • Animals are allowed or forced to move trough the entrance race in a line and plunge into the swim bath where they are completely immersed into the wash.
  • Animals then walk out of the swim bath using the exit ramp.
  • Animals are held in the drainage race so that excess dip wash drains off their bodies.
  • The first 10 to 20 animals to be dipped should be dipped again as they could have passed through the dip wash before it was well mixed.
  • The animals are then allowed to leave the drainage race.
  • Maintain the dipping routine.
  • Avoid dipping on a rainy day.
  • Mix the acaricide in the correct proportion.
  • Ensure that the roof is leak proof.
  • Ensure the correct level of dip wash in the dip tank.
  • Open the drainage pipe during dipping and close it after dipping.
  • Replenish the dip wash regularly.
  • Ensure that there is always adequate clean water in the foot bath to clean the hooves of the animals.
  • Close the return pipe after dipping to avoid dilution of the dip wash by rain.
  • Use acaricide that has not expired.
  • Ensure that the acaricide is thoroughly mixed before dipping.
  • Failure to follow the dipping routine.
  • Mixing a weak concentration of the acaricide.
  • Improper mixing of acaricide.
  • Leaking roof leading to dilution of the acaricide.
Dipping in a rainy day or hot day as rain washes away the acaricide before it sticks and can evaporate due to heat.
  • Low level of the dip wash in the dip tank.
  • Failure to replenish the acaricide.
  • Use of expired acaricide.
  • Accumulation of mud in the dip tank.
  • Animals are fully covered by the dip wash since total immersion allows complete body coverage.
  • Dip wash can be used several times especially when the strength of the wash is maintained.
  • Recommended for commercial livestock farmers where large numbers of animals are kept.
  • Spoilage of the acaricide is minimal.
  • It is cheaper in the long run.
  • It requires little labour to use.
  • It requires less technical skills to use than the spray race.
  • The cost of installing it is quite high for small scale farmers to afford.
  • It requires skills to detect concentration of wash.
  • It can not be used on calves, pregnant cows, sick animals and other small animals.
  • Animals can be injured especially when the level of the dip wash falls below the recommended level.
  • Dip wash can poison animals if poorly diluted or may not be effective if it is too dilute.
  • It is labour intensive and time consuming to empty and to refill.
  • Rain water may dilute the dip wash if wind blows off the roof.
  • It is not economical where there are few animals.
  • Contagious diseases such as foot and mouth can easily spread in the herd.
  • There may be leakage at the bottom and cracks on the wall when the construction is poor.
  • Pipes may accumulate pathogens like virus and bacteria
  • Seal off cracks once they appear in the dip tank to avoid losses of dip wash through leakage.
  • When emptied, the swim bath should be thoroughly cleaned and all sediments removed.
  • Vegetation around the dip tank should be slashed to avoid concealment. Uproot trees and shrubs that grow near the tank as their roots can damage the walls of the tank.
  • Repair leaking roofs to avoid dilution of dip wash by rain water and excessive evaporation during hot weather.
  • The dip tank should be fenced to avoid children and stray animals from falling in and drowning.
  • Top dip wash level where necessary.
  • Gammertox
  • Supona
  • Bacdip
  • Coopertox
  • Delnav
  • Decatix
  • Toxaphane
  • Supamix
  • Supona extra
Dip filling; this involves mixing and filling the dip tank with formulated acaricide.
  • Take note of the tank capacity
  • Take note of the acaricide to be used and recommended mixing ratio.
Example: An acaricide X(Decatix) is to be used in a dip tank whose capacity is 18,600 L. the recommended mixing ratio is 1: 500. The acaricide to be formulated will be; Mixing ratio x tank capacity 1 x 18,600 500

                             37.2L of acaricide

Boosting the tank; this is topping up of the dip tank with specified amount of formulated acaricide.
  • Take note of the tank capacity at the start of dipping i.e. 18,600L
  • Take note of the tank capacity after dipping i.e. 16,000L
Therefore; the amount of water to be added to the dip tank will be; 18,600 L – 16,000L   = 2,600L If the recommended acaricide ratio is 1:500, then the acaricide to be added to the dip tank will be; Ratio of mixing acaricide x   amount of water to be added. =      1 x 2,600 500 =        5.2 L of acaricide Dip testing; This involves checking whether the concentration of the dip wash is still effective. Dip wash concentration usually decreases with time and the frequency at which it is used. Farmers using the dip are advised to collect the well stirred dip wash in the bottle and take to the veterinary laboratory. The bottle should be labelled with information below; Farmer’s name, location, dip number, capacity of the dip tank, name of the acaricide used, the dipping interval   A SPRAY RACE: This is a farm structure that is used to control external parasites like ticks, mites and biting flies on animals. It consists of an enclosed race in which cattle are exposed to a dense spray delivered at a high pressure from a system of appropriately arranged jets/nozzles. The discharged fluid drains to the sump from which it is re-pumped as a spray. To ensure the efficiency of the spray race, the nozzles must be kept clean and so should the screen that traps dirt before the acaricide mixture returns to the sump.  Structure of a spray race.Udemy style 19     COMPONENTS OF A SPRAY RACE.
  • Has an entrance race where animals gather before moving into the crush. Ø Has a system of pipes with nozzles pointing inwards from all directions.
  • Has a foot bath for cleaning the hooves of animals before they move into the spray race.
  • Has two parallel walls that trap the splashing spray.
  • Has a concrete floor to minimize contamination of a spray wash and mud.
  • Has a roof which prevents rain water from entering and to trap the splashing spray wash.
  • Has a drainage race where the animals are retained for some time so that excess spray wash drips from their bodies.
  • Has a pump that forces the spray wash to move under pressure along the pipes.
  • Has filters which trap particles in the spray wash and prevent blockage of nozzles.
  • Has a sump/ reserviour where the spray wash is stored.
  • The spray wash is pumped from the sump or reserviour and forced to move along pipes at a high pressure.
  • The spray wash emerges through the nozzles which break it down into small misty droplets.
  • The animals are allowed to walk through the race towards the drainage race in a line/single file and they are fully covered by the spray wash.
  • The sprayed wash and that dripping from the animals drain back to the reserviour via filters that remove foreign particles then it is re circulated to the system.
  • It is cheaper to install than a dip tank and thus easier for individual farmers to install and maintain it.
  • It uses a small quantity of spray.
  • The farmer is able to change the type of acaricide at every spraying without the expense of having to re-fill a large tank capacity.
  • Many animals can be sprayed in a short time. Ø Less labour is needed to operate a spray race.
  • It can be used to spray small animals such as goats and sheep.
  • It can also be used to spray calves and pregnant cows that are about to deliver since it causes fewer disturbances on the animals.
  • Fresh acaricide is used always thus ensuring good quality and effectiveness of the spray wash.
  • Nozzles can easily be blocked by dirt in the spray.
  • There are possibilities of certain parts of the animal’s body not being covered by spray wash.
  • Requires technical skill to operate the spray race.
  • It needs reliable power source to run the pump at the required speed. Ø It is only economical with a large herd.
HANDLING YARDS. These are enclosures attached to every animal handling layout for gathering animals together before they are directed into dips and spray races. They are also used for;
  • General handling of livestock
  • Culling
  • Sorting out animals for sale
  • General observation of the animals.

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