WAEC SSCE - Animal Husbandry - 2021 (Essay)

Antwoorddetails

(a) Completed table on forage crops

(b) i. Definition of pasture

Pasture is an area of land covered with grasses and legumes (herbage) that is used for grazing or feeding livestock such as cattle, sheep and goats.

(b) ii. Four ways a grass-legume mixture is important in livestock production

• The legume component fixes atmospheric nitrogen through its root nodules, enriching the soil and improving the growth and yield of the companion grass.
• It supplies a balanced diet, since the grass provides energy (carbohydrate) while the legume supplies protein, giving the animal a more complete ration.
• It raises the total feeding value and palatability of the herbage, so animals eat more and gain weight or produce milk faster.
• The mixture gives a denser, all-year ground cover that protects the soil from erosion and suppresses weeds.

(c) Six characteristics of rangelands

• They are large expanses of natural, uncultivated land carrying native grasses, herbs and shrubs.
• The vegetation grows naturally and is not planted or managed by man.
• They occur mostly in semi-arid regions with low and unreliable rainfall.
• Animals feed by grazing and browsing directly on the natural herbage.
• They are generally of low carrying capacity, supporting few animals per unit area.
• The forage quantity and quality vary greatly with season, being lush in the wet season and scarce and dry in the dry season.

Antwoorddetails

(a) Terms used in the slaughtering of farm animals

• Scalding: dipping the slaughtered carcass or bird in hot water so as to loosen the feathers, hair or bristles for easy removal.
• Singeing: passing the carcass over or through a flame to burn off the remaining hair, feathers or bristles left on the skin.
• Evisceration: the removal of the internal organs (viscera such as the intestines, lungs and heart) from the slaughtered carcass.

(b) Four agents involved in the marketing of farm animals and animal products

• Wholesalers
• Retailers
• Middlemen/brokers (commission agents)
• Transporters/processors

(c) Five marketing functions that facilitate the sale of chicken and eggs

• Buying and selling.
• Transportation of the products to the market.
• Storage/preservation of the products.
• Grading and standardisation of eggs and birds.
• Packaging, and advertising/provision of market information.

(d) Three stages in the life cycle of a roundworm

• Egg
• Larva
• Adult worm

(e) Two methods of animal improvement

• Selection
• Breeding (cross-breeding/hybridisation), or introduction/artificial insemination.

Antwoorddetails

(a) Four ways in which livestock is important

• Source of food such as meat, milk and eggs.
• Source of income and foreign exchange to the farmer and nation.
• Source of raw materials for industry (hides, skin, wool, bone).
• Source of organic manure for crop production, and of draught (work) power.

(b)(i) Six organs of the digestive system in rabbits

• Mouth
• Oesophagus
• Stomach
• Small intestine
• Caecum (large in the rabbit)
• Large intestine (rectum/anus)

(b)(ii) Two functions of the alimentary canal

• Digestion of food into simple absorbable forms.
• Absorption of digested nutrients into the blood, and egestion of undigested material.

(c)(i) Four functions of the liver

• Secretes bile which emulsifies fat during digestion.
• Stores glycogen, vitamins and minerals (e.g. iron).
• Detoxifies harmful/poisonous substances in the body.
• Deaminates excess amino acids and destroys worn-out red blood cells.

(c)(ii) Two parasites found in the liver of cattle

• Liver fluke (Fasciola species).
• Hydatid cyst (larva of the tapeworm Echinococcus).

(d) Two differences between the digestive systems of a goat and a rabbit

Antwoorddetails

(a) Six activities carried out in the brooding of chicks

• Providing artificial heat/warmth for the chicks with a heat source (charcoal pot, electric bulb or gas brooder).
• Supplying clean, cool drinking water in shallow drinkers.
• Providing feed (chick starter/mash) in clean feeders.
• Spreading clean, dry litter/bedding on the floor and replacing wet litter.
• Providing adequate lighting and ventilation in the brooder house.
• Vaccinating and medicating the chicks and guarding them against predators and rodents.

(b) Management practices

• Deworming: the administration of anthelmintic drugs to animals to remove or destroy internal parasites (worms) living in the digestive tract, so as to improve health and productivity.
• Culling: the removal (and disposal) of unproductive, sick, deformed or unwanted birds from the flock so that only healthy, productive birds are kept.
• Debeaking: the trimming of part of the upper (and sometimes lower) beak of birds to prevent cannibalism, feather pecking, egg eating and feed wastage.
• Delousing: the treatment of birds with insecticides/pesticides to destroy external parasites such as lice and mites.

(c) Four signs of ill health in poultry

• Dullness and reduced activity, with the bird often isolating itself from the flock.
• Loss of appetite and reduced feed and water intake.
• Ruffled or rough feathers and a drooping appearance.
• Sudden drop in egg production, and diarrhoea with a soiled vent.

(d) Two organs of the circulatory system of farm animals

• The heart.
• The blood vessels (arteries, veins and capillaries).

Antwoorddetails

(a)(i) Meaning of brooding

Brooding is the rearing and care of young chicks under artificial heat/warmth from day-old until about six to eight weeks of age, when they are able to regulate their own body temperature and no longer need extra heat.

(a)(ii) Four routine activities carried out in a brooder house

• Providing and regulating artificial heat for the chicks.
• Supplying clean feed and water.
• Cleaning the house and replacing wet/dirty litter.
• Vaccinating/medicating the chicks and removing dead or sick ones.

(b) Four effects of parasites in livestock production

• They reduce productivity (lower weight gain, milk and egg yield).
• They cause or transmit diseases.
• They cause anaemia through blood sucking and damage tissues/organs.
• They cause emaciation and may lead to the death of the animal.

(c) Four ways of controlling liver fluke in sheep production

• Drain marshy/waterlogged grazing land.
• Control the snail intermediate host using molluscicides.
• Drench the sheep with anthelmintics/flukicides.
• Practise rotational grazing and avoid grazing wet pasture in the early morning or late evening.

(d)(i) Definition of artificial insemination

Artificial insemination (A.I.) is the mechanical introduction of semen collected from a selected male into the reproductive tract of a female animal without natural mating.

(d)(ii) Four advantages of artificial insemination in cattle production

• It allows a single superior bull to serve many cows.
• It prevents the spread of breeding/venereal diseases.
• Semen can be stored and transported over long distances.
• It reduces the cost of keeping many bulls and overcomes size differences between animals.

Antwoorddetails

(a) Five ways of preventing malnutrition in farm animals

• Providing a balanced/adequate ration that supplies all needed nutrients.
• Supplementing feed with vitamins and minerals (e.g. mineral licks).
• Providing clean, adequate drinking water at all times.
• Avoiding overcrowding so that every animal has access to feed.
• Deworming animals regularly to reduce nutrient loss to parasites, and feeding according to age and physiological status.

(b) Rickets in farm animals

(i) Causes:

• Deficiency of vitamin D in the diet.
• Deficiency or imbalance of calcium and phosphorus in the ration.

(ii) Symptoms:

• Bent, bowed or deformed leg bones.
• Swollen joints, weak bones and stunted growth/lameness.

(iii) Control measures:

• Supply vitamin D and expose animals to sunlight.
• Provide adequate calcium and phosphorus in a balanced ration.

(iv) Animals which could be affected:

• Young growing poultry (chicks).
• Young pigs, calves, lambs and kids.

(c) Meaning of additive

An additive is a non-nutrient substance added to animal feed in very small quantities in order to improve the quality, palatability or keeping quality of the feed, promote growth or prevent disease.

(d) Five reasons why additives are included in animal feed

• To promote faster growth and improve feed efficiency.
• To prevent and control diseases (medication/coccidiostats).
• To improve the palatability of the feed.
• To supply extra vitamins and minerals.
• To preserve the feed and prevent spoilage/rancidity, and to improve product quality (e.g. yolk colour).