WAEC SSCE - Animal Husbandry - 2017 (Essay)

Answer Details

(a) Six causes of low egg production in chicken

• Poor feeding/inadequate nutrition (especially low calcium).
• Diseases and parasite infestation.
• Poor breed/inferior genetic make-up.
• Old age of the laying birds.
• Stress from heat, noise or rough handling.
• Inadequate lighting/short day length and overcrowding.

(b) Three parts of the digestive system of pigs

• Mouth
• Stomach
• Small intestine (also oesophagus, large intestine and anus)

(c) Six ways in which cattle production is important in West Africa

• Source of meat (beef) for food.
• Source of milk and milk products.
• Source of income and foreign exchange.
• Source of hides and skin for industry.
• Provide manure for crop production and draught (work) power.
• Source of employment and a means of savings/wealth.

(d) Five uses of poultry eggs

• Source of food rich in protein.
• For hatching to produce chicks.
• Raw material in baking and confectionery.
• Used in vaccine production.
• Used in cosmetics/pharmaceuticals and as a source of income.

Answer Details

(a) Three management systems in farm animal production

• Extensive system
• Semi-intensive system
• Intensive system

(b) Three ways in which housing is important

• Protects animals from adverse weather (rain, sun and cold).
• Protects animals from predators and thieves.
• Eases management (feeding, cleaning, medication and record keeping) and prevents animals from wandering.

(c) Four advantages of each system

(i) Deep litter:

• Requires less labour to manage.
• Birds have room to exercise, reducing boredom.
• The litter provides warmth and vitamin B and can later be used as manure.
• Cheaper to construct than cages.

(ii) Battery cage:

• Allows efficient use of space (high stocking density).
• Poor layers are easily identified and removed.
• Eggs are clean and rarely soiled or broken.
• Reduces cannibalism/egg eating and eases disease and parasite control.

(d) Three features of a suitable housing unit for rearing

(i) Snails:

• Moist/humid environment with loose, well-drained soil.
• Shaded/covered from direct sunlight.
• Escape-proof and protected from pests.

(ii) Grasscutter:

• Strong, escape-proof pen.
• Dry and well ventilated.
• Easy to clean and protected from predators, with hiding/nesting space.

Answer Details

(a) Four functions of carbohydrates in farm animals

• Provide energy and heat for body activities.
• Excess is stored as fat (reserve energy) and glycogen.
• Spare protein so that it is used for growth rather than energy.
• Provide raw material for the formation of fat and milk.

(b) Four organs associated with respiration

• Nostrils/nose
• Trachea (windpipe)
• Bronchi
• Lungs (also air sacs in birds and the diaphragm)

(c) Two diseases that affect the respiratory system

• Pneumonia
• Chronic respiratory disease (CRD), also infectious bronchitis and contagious bovine pleuropneumonia (CBPP)

(d) Definitions of terms used in animal physiology

• (i) Exhalation: the breathing out or expulsion of air (rich in carbon dioxide) from the lungs to the atmosphere.
• (ii) Inhalation: the breathing in or taking in of air (rich in oxygen) from the atmosphere into the lungs.
• (iii) Peristalsis: the wave-like rhythmic contraction and relaxation of the muscles of the alimentary canal that moves food along the gut.
• (iv) Ovulation: the release of a mature ovum (egg) from the ovary.
• (v) Rumination: the regurgitation, re-chewing and re-swallowing of cud by a ruminant animal.

Answer Details

(a) Three reasons for keeping goats

• For the production of meat (chevon), which is a valuable source of animal protein.
• For the production of milk, especially from dairy breeds such as the West African Dwarf and Saanen.
• For the production of skin and hair, and for the sale of animals to earn income.

(b) i. Definition of oestrus

Oestrus (heat) is the period during the reproductive cycle when a female farm animal is sexually receptive and willing to accept the male for mating, and during which ovulation normally occurs.

(b) ii. Three signs of heat in a sow

• Swelling and reddening of the vulva.
• Restlessness with frequent mounting of, or standing to be mounted by, other pigs.
• A mucous discharge from the vulva and the standing (immobility) reflex when pressure is applied to the back.

(c) Completed table

Answer Details

(a) Definition of animal improvement

Animal improvement is the application of scientific principles and techniques (mainly selection and breeding) to develop farm animals with more desirable/superior qualities such as higher yield, faster growth and disease resistance from one generation to the next.

(b)(i) Meaning of introduction

Introduction is the bringing in of animals of superior/improved breeds from another place or country into a new environment in order to improve the local stock or for production.

(b)(ii) Advantages and disadvantages of introduction

Three advantages:

• It is quicker/faster than developing a breed through breeding.
• It brings in superior, high-yielding breeds.
• It may introduce disease-resistant breeds and saves the cost of local breed development.

Three disadvantages:

• Introduced breeds may fail to adapt to the new climate/environment.
• They may introduce new diseases and pests.
• Importation is expensive and the breeds may not perform as expected without special management.

(c)(i) Definition of progeny selection

Progeny selection is the selection of breeding animals based on the performance/qualities of their offspring (progeny) rather than on the individual animal's own performance.

(c)(ii) Five desirable characteristics used in selecting animals for improvement

• High productivity (milk, meat or egg yield).
• Fast growth rate.
• Disease resistance.
• High fertility/prolificacy.
• Good feed conversion efficiency and good body conformation.

(d) Three advantages of artificial insemination

• A single superior sire can serve many females.
• It controls the spread of breeding diseases.
• Semen can be stored and transported over long distances, reducing the cost of keeping males.

Answer Details

(a) Definition of digestion

Digestion is the process by which large, complex, insoluble food substances are broken down (mechanically and chemically by enzymes) into simple, soluble and absorbable forms in the alimentary canal of the animal.

(b) Four differences between the digestive systems of a chicken and a goat

(c) Five methods of improving rangeland

• Controlled/rotational grazing.
• Reseeding with improved forage species.
• Application of fertilizer or manure.
• Weed control.
• Irrigation and controlled burning.

(d) End product of digestion of each nutrient

• (i) Carbohydrate: glucose (simple sugars).
• (ii) Protein: amino acids.
• (iii) Fat and oil: fatty acids and glycerol.

(e) Four functions of proteins in farm animals

• Growth and building of body tissues.
• Repair of worn-out tissues.
• Formation of enzymes and hormones.
• Production of antibodies for immunity (and of milk and eggs).

(f) Two digestive enzymes found in the small intestine of a pig

• Trypsin
• Lipase (also maltase and pancreatic amylase)