Question 6
(a) Mention five advantages and three disadvantages of castration in livestock production. (8 marks)
(b) (i) Draw and label five parts of the digestive system of a domestic fowl.
(ii) State one function of each of the parts labelled in (b)(i). (12 marks)
Observation
This question was least popular among candidates and many of them avoided it. Although candidates who attempted the question were able to state the advantages and disadvantages of castrating livestock, majority of them were unable to draw the digestive system of a domestic fowl. Many candidates also do not know the functions of parts of the chicken digestive system.
The expected answers include:
(a) Advantages of castration in livestock production
- Prevents indiscriminate mating/breeding control
- Increased animal weight/growth improvement
- Improved meat quality
- Animals are docile for easy handling
- Removal of male odour
- Improvement of market value
Disadvantages of castration in livestock production
- Blood may be lost in the process
- If not well treated, wound may persist
- There could be excess deposit of fat
- Wound may become infected
- Desirable traits may be lost
- It is stressful/painful to the animal
- Death may occur
(b) (i) Drawing of digestive system of domestic fowl
(ii) Functions of parts
Beak - Picks the feed
- Moistens the feed
Oesophagus/gullet/gut/throat - Passage for feed from mouth to crop
Crop - Temporary storage of feed
- Further moistening of feed
Proventriculus - Secretion of gastric juice/digestive enzyme
- Digestion of proteins
Gizzard - Grinding of feed
Ventriculus - Mixing/churning of feed
Small intestine - Digestion of feed
- Secretion of digestive enzymes
- Absorption of nutrients
Large intestines - Absorption of water
Pancreas - Secretion of pancreatic juice
Liver - Secretion of bile
Gall bladder - Storage of bile
Caeca/caecum - Microbial fermentation
- Absorption of water
Rectum - Absorption of water
- Collection of feacal material
Cloaca/anus/vent - Passage for droppings