(a) Write short notes on the following systems of breeding: (i) In-breeding; (ii) Line-breeding; (iii) Cross-breeding (b) State three methods of collecting ...
Question 1 Report
(a) Write short notes on the following systems of breeding: (i) In-breeding; (ii) Line-breeding; (iii) Cross-breeding
(b) State three methods of collecting semen from a proven male for use in artificial insemination.
Answer Details
(a) Systems of breeding
(i) In-breeding: The mating of closely related animals, for example brother to sister or parent to offspring, within the same breed. It is used to fix and concentrate desirable characteristics and to produce pure lines, but if continued it can lead to inbreeding depression (loss of vigour and fertility).
(ii) Line-breeding: A milder form of in-breeding in which animals are mated to keep them closely related to one outstanding ancestor (for example grand sire to grand daughter), but not as close as parent-offspring mating. It aims to retain the good qualities of a superior ancestor while reducing the harmful effects of close in-breeding.
(iii) Cross-breeding: The mating of animals of two different breeds. It combines the desirable qualities of both breeds and produces offspring with hybrid vigour (heterosis), which are often more vigorous, faster growing and more productive than either parent.
(b) Three methods of collecting semen from a proven male for artificial insemination
- Use of an artificial vagina.
- Electro-ejaculation (electrical stimulation).
- Massage method (manual massage of the ampullae/rectal massage).
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