AGB 211: Livestock and Poultry Breeding (2+1)

CROSS BREEDING

• Cross breeding is mating of two individuals from different breeds. Breed represents tremendous resources of varying genetic material. Cross breeding is done. Cross breeding is done to exploit hybrid vigor or heterosis and to sell the crossbred to market. Every time, the parental breeds have to be crossed for producing market animal.
• Crossbreeding has been used in recent years to establish a broad genetic base in the development of new breeds or synthetics: one or two crosses between the two or more populations are made in order to produce a single population of animals containing genes from each of the population involved. Once a synthetic has been formed then the main aim is to improve it as rapidly as possible by selection within it. For example: Santa Gertrudis, The Jamaica Hope, the Norwegian Red and White, the Australian Milking Zebu, Hissardale, Karan Swiss, Sunandhini, Taylor breed. The main guidelines to be followed in crossing to produce a synthetic are:
• Ensure that the animals used in the original crossings have been intensely selected in terms of relevant characters; it is of no use starting a synthetic with inferior animals.
• Maximise variance in breeding values amongst the foundation animals in the synthetics using as many unrelated animals as possible from each of the contributing populations.