Effect of some factors (parity, birth type and litter size) on the milk productivity in sheep from the Bulgarian Dairy Synthetic Population

Nevyana Stancheva, Teodora Angelova, Daniela Yordanova, Jivko Krastanov

Резюме: The aim of the study was to determine the effect of some factors (parity, birth type and litter size) on milk productivity in the test-day (TDY), milk yield per milking period (TMM), average daily milk yield per milking period (ADMYmilking period) and milk yield per standard 120-day milking period (TMM120) in sheep from the Bulgarian Dairy Synthetic population from the flock of the Agricultural Institute – Shumen. The data on the milk productivity of 1078 ewes born in 2007–2017 and produced in the period 2009–2020 were analyzed. The statistical analysis included fixed factors: parity, litter size in a specific lambing for each successive lactation, birth type, permanent environmental effect, effect on individual genetic value and effect caused by other unobserved factors. Mean values for TDY 0.903 l ± 0.35; TMM 125.625 l ± 40.16; The ADMYmilking period of 0.875 l ± 0.25 and TMM120 of 105.117 l ± 30.22 were found at the suckling period of 51 ± 13.18 days and a milking period of 143 ± 19.79 days. A highly significant effect was found for the parity factor on all studied traits (P ≤ 0.001). The birth type did not affect only the milk yield on the test day, and litter size had an effect only on the average daily milk yield for the milking period (P ≤ 0.05).

Ключови думи: birth type; Bulgarian Dairy Synthetic Population; litter size; milk yield; parity; sheep

Дата на публикуване: 2022-12-21