Open Nucleus Breeding System (ONBS)
The basic idea of Open Nucleus Breeding System (ONBS) using Multiple Ovulation and Embryo Transfer (MOET) is to set an elite herd (or a few elite herds) of males and females and carry out intensive selection and testing within herd/s selecting males and females at an early age using family information and not on their progenies as in the case of the Progeny Testing Programme or just on their parents as in the case of pedigree selection.
Since the merit of males is judged on the basis of performance of their sisters and half-sisters – referred to as sibling test – and not on the performance of their progenies, the generation interval is considerably reduced. Although, the accuracy of selection under sibling test is lower than that achieved in the progeny test, the benefits of reducing the generation interval outweighs the loss of accuracy. The genetic response under a well-run ONBS could be as high as that is achieved under the conventional progeny-testing programme. As selection and testing is done within a herd or in a few herds, the greater degree of control on the determinants of genetic change i.e. intensity of selection, generation interval and accuracy of selection is possible.