S. BOIKOVSKI, N. STANCHEVA, G. STEFANOVA and D. DIMITROV
Agricultural Institute, BG-9700 Shumen, Bulgaria
BOIKOVSKI, S., N. STANCHEVA, G. STEFANOVA and D. DIMITROV, 2003. Influence of some factors on milk yield trait of sheep from the Newly created milk sheep breed. Bulg. J. Agric. Sci., 9: 243–249
The objective of this study was to investigate the effect of some factors on milk yield trait in sheep from the Newly created milk sheep breed in Bulgaria. It was established that in young sheep (at 1st lactation) there was linear differentiation in respect to milk yield trait and inbreeding depression in closely related animals, which was surmounted at older age.
The birth year as a source of variation significantly influenced milk yield at 1st and 2nd lactation in sheep from the Newly created milk sheep breed (P < 0.001). The heritability coefficients (h2) of milk yield trait at 1st and 2nd lactation (complete and 200-day standard lactation) had very high values, which showed that the phenotypic selection in sheep by this trait would be successful at this stage of breeding.