Inbreeding - Practice Questions & MCQ

• Animal breeding aims at increasing the yield of animals and improving the desirable qualities of the produce.
• A group of animals related by descent and similar in most characteristics like general appearance, features, size, configuration, etc., are said to belong to a breed.
• Animal breeding is of two types:
  • When breeding is between animals of the same breed, it is called inbreeding.
  • When crosses are made between different breeds, these are called outbreeding.

Inbreeding:

• Inbreeding refers to the mating of more closely related individuals within the same breed for 4-6 generations. 
• The breeding strategy is as follows – superior males and superior females of the same breed are identified and mated in pairs.
• The progeny obtained from such matings are evaluated and superior males and females among them are identified for further mating. 
• A superior female, in the case of cattle, is the cow or buffalo that produces more milk per lactation. 
• On the other hand, a superior male is a bull, which gives rise to superior progeny as compared to those of other males.
• Inbreeding increases homozygosity.
• Thus inbreeding is necessary if we want to evolve a pure-line in any animal.
• Inbreeding exposes harmful recessive genes that are eliminated by selection.
• It also helps in the accumulation of superior genes and the elimination of less desirable genes. 
• Therefore, this approach, where there is the selection at each step, increases the productivity of the inbred population. 
• However, continued inbreeding, especially close inbreeding, usually reduces fertility and even productivity. 
• This is called inbreeding depression.
• Whenever this becomes a problem, selected animals of the breeding population should be mated with unrelated superior animals of the same breed. 
• This usually helps restore fertility and yield.