Genetic and environmental influences on calf birth weight of Butana cattle breed in Sudan

Abstract

This study was conducted to estimate the effect of some genetic and environmental factors 
on calf birth weight of Butana cattle breed. The study included 1839 records of 562 Butana 
cows at Atbara Livestock Research Station covering the period from 1949 to 1999. The 
analysis of variance revealed that sire, parity number and sex of calf influence significantly 
(P<0.05) calf birth weight, while year season of calving did not (P>0.05). 
The least squares mean for calf birth weight was found to be 25.26±0.305 kg with a 
coefficient of variation of 13.26%. Also the result showed that the calf birth weight had a 
heritability of moderate magnitude (0.20±0.15). The genetic correlations of birth weight 
with lactation milk yield, lactation length, dry period, calving interval and age at first 
calving were -0.21±0.22, 0.42±0.22, 0.41±0.25, 0.08±0.26 and 0.22±0.27 respectively. The 
phenotypic and environmental correlations with all traits studied were small and negative.