Effects of non-genetic factors on growth traits and survival rate in Karacabey Merino lambs

Abstract

This study was conducted with the aim of determining the growth characteristics and survival rate of Karacabey Merino lambs, as well as the non-genetic factors affecting these traits. The study included data from a total of 17659 lambs and 12263 ewes raised in 30 herds between the years 2011 and 2016 as part of the National Sheep and Goat Improvement Project. The aver-age birth weight of the lambs was determined as 3.73 +/- 0.05 kg, the average 45th day live weight was 18.43 +/- 0.58 kg, the average weaning (average 91.8 days) weight was 31.83 +/- 0.24 kg, and the average daily live weight gain until weaning was 289.1 +/- 3.91 g. The average survival rate of lambs at weaning was calculated to be 95.67% +/- 1.15. The effects of the factors herd, birth year, birth type, birth season and sex were found significant for all traits (p<0.01). It was established that the mortality rate in lambs in large herds was higher during 6 years in which the project was carried out. Due to the high twinning rate in large herds, the number of lambs per worker is increased, and as a result, they cannot be adequately cared for. For this reason, large farms may be encouraged to increase workmanship services in addition to being provided with protective health practices for lambs throughout the birth period. On the other hand, it was determined that the twinning rate was low in small farms. On farms with fewer sheep populations, it may be advised to flush or administer exogenous hormone treatments to ewes in order to increase fertility and help them bear twins.