Observation

            Question 3 was a bit challenging for many candidates and marks were below average.

1. Although many candidates were able to state the functions of progesterone

and androgen, very few of them could state the functions of oestrogen
and luteinizing hormone.

1. Many candidates displayed poor knowledge of botanical names and type of common forages. They also failed to follow the scientific convention of writing botanical names of species; thus losing marks.

The expected answers include:

(a)        Functions of reproductive hormones in livestock
            (i)         Progesterone

• Ensures implantation of fertilized ovum
• Maintains pregnancy
• Inhibits oestrus
• Causes the development of alveoli in the mammary gland
• Supports lactation
• Supports thyroid function

            (ii)        Androgen

• Initiates spermatogenesis
• Responsible for the development of male secondary sexual characteristics
• Maintains sex drive/libido
• Sustains the life of sperms in the epididymis
• Reduces fat deposition
• Enhances muscular growth
• Enhances skeletal growth
• Promotes the growth of accessory sex glands

            (iii)       Oestrogen

• Stimulates growth of ducts in the udder
• Promotes egg production
• Induces rapid multiplication of epithelium in the vagina
• Increases blood supply to uterus
• Increases the water content of uterus
• Prepares the uterus for reception of fertilized ovum
• Stimulates the development of female secondary sex characteristics
• Increases cilliary activities and mucous secretion in the vagina

            (iv)       Luteinizing hormone

• Causes rupture of graafian follicle
• Stimulates release of ova
• Stimulates secretion of oestrogen and progesterone

 (b)       Completion of table

           
(c)        Methods of natural mating in animal production

• Pen mating
• Flock mating /herd mating
• Hand/stud mating
• Pasture mating