STUDYING THE VARIATION OF PRODUCTIVE TRAITS MILK YIELD AND FERTILITY OF DAIRY SHEEP FROM BULGARIAN SYNTHETIC POPULATION AS A RESULT OF CONDUCTED SELECTION

P. Slavova, S. Laleva, Y. Popova

Abstract: Analyzing the level of productivity in individual herds and the entire dairy crossbred population significantly affect the right direction of breeding process, aimed at improving its valuable productive and quality traits. The aim of the study is to observe the changing trends - milk yield and fertility of Synthetic population Bulgarian dairy sheep (SPBM) for the period 2006-2012. Object of the study are dairy sheep from Bulgarian Synthetic population in the farm of Agricultural Institute - Stara Zagora. The selection traits we examined and analyzed are milk yield and fertility at animals of different ages during the period of their economic use 2006-2012 year and on year of birth. Variation of milk yield is observed from I-st to IV-th lactation and fertility - from I-st to IV-it lambing, i.e. up to 5.5 years of age. Part of the animals born in 2008 and 2010 have one more lambing and lactation as they have mated and lambing as (weaned) lambs. Sheep from flock SPBM are characterized with milk yield and fertility, responding to the selection limits for dairy tribal sheep. Fertility increased from first to third lambing - from 126.2% to 140.2% / for 100 ewes / and average daily milk yield increases with the sequence of lactation - from 0.843 l. to 0.997 l. Improvement and consolidation of the main productive traits at breeding activities in the flocks of population should continue through establishing of optimal conditions for the realization of own genetic potentialities of the animals.

Keywords: fertility; milk yield; production traits; sheep

Date published: 2017-03-14