Department of Livestock Production Management, College of Veterinary and Animal Sciences, Bikaner, Rajasthan-334001, India
Online published on 19 December, 2013.
The present investigation was carried out to study the influences of environmental factors on the pre weaning growth traits in Chokla sheep maintained at the Livestock farm Sikar,Rajasthan. The data were collected from 2010 to 2012. Means± SE were 2.84 ± 0.009 kg for birth weight, 7.64 ± 0.014 kg for weight at around 60 days of age, 12.64 ± 0.03 kg for weaning weight and 12.55 ± 0.03 kg for weaning weight adjusted to 120 days of age. Statistical analyses were performed by using the mixed procedure of the SAS statistical package program. The model included the effects of year and season of birth, sex, type of birth, parity, age and weight of dam at lambing, and two-way interactions between these factors. Results showed that all pre weaning traits were significantly (P < 0.05) affected by year, sex, interaction between year and season, and interaction between year and sex of lamb. A significant interaction (P < 0.05) between season and sex existed for both weaning traits. In addition, weaning weight adjusted to 120 days was also significantly affected by the interaction between sex and type of birth. Birth weight was affected (P < 0.05) by season, birth type and parity. Age and weight of dam were not significant factors for pre weaning traits. The non-significance of type of birth on pre weaning growth may have been partly due to the low rate of twin births (2%) for Chokla sheep in this population. Findings here suggested that farm management must be appropriately changed to compensate for changes in environmental effects over time.
