Dynamics of the selection traits milk yield and fertility in sheep from the Bulgarian Dairy Synthetic population

Margarit Iliev, Genoveva Staykova, Todor Tsonev

Abstract: The subject of the study were 254 ewes from the Bulgarian Dairy Synthetic population, owned by
the Institute of Agriculture – Karnobat, born in the period 2013–2018. The aim of the study was to
establish the dynamics of milk yield and fertility in sheep. The selection traits of milk yield of a standard
120-day period, duration of milking period and biological fertility by years of birth in animals
of different ages have been studied and analyzed. The dynamic of milk productivity for 120 days was
monitored from I to IV lactation, and biological fertility was monitored from I to IV lambing, until
reaching 5.5 years. The data from the performed controls were processed by the method of variation
statistics. It was established that the average milk yield for a standard 120-day period (108.6l), average
daily milk yield (0.905 l) and duration of the milking period (140.6 days) were the highest during
third lactation. Biological fertility of sheep increased from 134.2% to 154.1% during the time from the
first to third lambing. The analyses of the obtained results indicate sufficient perspectives for increasing
the potential and real productivity of sheep from the studied herd of Bulgarian Dairy Synthetic
population.

Keywords: Bulgarian dairy Synthetic sheep; fertility; milk yield; selection traits

Date published: 2022-04-26