The influence of birth type and sex on rearing of Polish Heath and Żelaźnieńska lambs

Abstract

The aim of the study was to determine the effect of birth type and sex on lambs survival parameters of polish heath and żelazneńska sheep. The research included data, which was used to determine the prolificacy index, the percentage of live-born lambs and the lambs rearing index up to 100 days of age. A higher prolificacy index (P≤0.01) and a higher percentage (P≤0.01) of reared lambs were determined in the polish heath compared to the żelazneńska sheep. In the herd of the first breed, a greater proportion of twin and more numerous litters than singleton births were noted. Single and twin litters were dominant in the żelazneńskie sheep. The rearing rate of lambs from single litters was at a similar level in both observed breeds. However, in the herd of polish heath sheep, lambs from multiple litters shoved also high rearing rate. Single ram lambs were characterized by higher (P≤0.01) body weight at birth and at 56 days of age compared to twin born and ewe lambs, both in polish heath sheep and żelazneńska sheep. Statistical differences (P≤0.01) in body weight at birth and on 56th day of age were also recorded between twins and triplets in polish heath sheep. The analysis of the distribution of lambs' mortality during the rearing period has shown that the most critical is the first week of life of the born offsprings.

Keywords

• sheep
• breed
• lamb rearing
• type of birth