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

STRUCTURE OF ONBS

• The structure is in the form of a pyramid. It consists of three-tier multiplication systems, namely the nucleus tier, multiplier tier and the commercial tier.

Nucleus tier

• It is composed of top parental breeding stock. It consists of 10 – 15% of total breed population and these are selected exclusively on their breeding value. This tier acts as selector and supplier of replacement male and female breeding stock for itself and for multiplier tier at farm level and commercial tier at field level. It is stationed at a particular place with all necessary inputs of land, feed, labour and favourable environment.

Multiplier tier

• This is constituted by about 30-40 percent of breed population. It acts as multiplier and tester population. It exclusively receives stud males and sometimes breeding females from the nucleus herd with the sole purpose of producing sufficient number of breeding animals therby satisfy the demands of herds in the commercial tier.

Commercial tier

• This is constituted by about 40 – 60 percent of breed population and generated using males and females that are produced under multiplier herds with the intention of increasing the production and the genetic improvement. It acts as terminal tier of hierarchical breeding structure.
• ONBS concept involves introduction of superior quality females to the sire breeding nucleus, like semen stations from other tiers of breeding. Although bulls are considered as the chief architect genetic improvement in cattle and buffaloes due to high selection intensity and advent of AI and frozen semen technology the expected genetic gain is limited. This is overcome by ONBS to some extent where both males and females contribute to the total annual genetic gain in this system. The expected genetic gain may be increased by 10 – 15 per cent.