Strategies for Enhancement in Food Reproduction — BIOLOGY STD 12 Science — Question
Gujarat BoardEnglish MediumSTD 12 ScienceBIOLOGYStrategies for Enhancement in Food Reproduction3 Marks
Question
Explain out-breeding, out-crossing and cross-breeding practices in animal husbandry.
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Answer
Out-breeding: Out-breding is the breeding of the unrelated animals, which may be between individuals of the same breed but having no common ancestors for 4-6 generations (out-breeding) or between different breeds (cross-breeding) or different species (inter-specific hybridisation).
Out-crossing: This is the practice of mating of animals within the same breed, but having no comon ancestors on either side of their pedigree up to 4-6 generations. The offspring of such a mating is known as an outcross. It is the best breeding method for animals that are below average in productivity in milk production, growth rate in beef cattle, etc. A single outcross often helps to overcome inbreeding depression.
Cross-breeding: In this method, superior males of one breed are mated with superior females of another breed. Cross-breeding allows the desirable qualities of two different breeds to be combined. The progeny hybrid animals may themselves be used for commercial production. Alternatively, they may be subjected to some form of inbreeding and selection to develop new stable breeds that may be superior to the existing breeds. Many new animal breeds have been developed by this approach. Hisardale is a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Marino rams.
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