PRODUCTIVE PERFORMANCE AND HERITABILITY OF SOME TRAITS OF THE SYNTHETIC POPULAION BULGARIAN MILK SHEEP

N. Stancheva

Резюме: A study was initiated with the aim to make a productive characterization of some traits as affected by year of birth, as well as to carry out an evaluation of their heritability in the sheep from the Synthetic Population Bulgarian Milk (SPBM). It assigned 851 ewes borne during the period 2004-2008 on the experimental farm of Agricultural Institute – Shumen. It was established that the average milk yield per standard 120-day lactation period after first and second parity is highest in the ewes borne in the year 2008 (107.01 l and 106.54 l respectively), the performance of those borne in 2007 being also relatively high (96.97 l and 109.16 l respectively), all of which are in compliance with and over the requirements for class I and class Elite of the population. Highest is the biological prolificacy of the ewes borne in 2008 – 1.40 lambs per ewe at the age of 2.5 yr, 1.55 at 3.5 yr, and 1.75 at 4.5 yr. Year of birth showed to plays highly significant effect on the traits 120-day milk yield at second lactation and live weight at all ages. Though to lesser extent, also significantly affected are milk yield at first lactation and biological prolificacy at 2.5 yr. The significance of the effect of linage on 120-day milk yield at first lactation and live weight at 9 monts is high, while that on live weight at 1.5 and 2.5 yr is marginal. The established heritabil¬ity coefficients of the studied traits, subjected to selection in the herd, have from low to moderately high values.

Ключови думи: heritability; live weight; milk yield; prolificacy; Synthetic Population Bulgarian Milk Sheep; year of birth

Дата на публикуване: 2017-05-23