Effect of genetic and non-genetic factors on lactation yield in Sahiwal cattle

Abstract

The aim of the present study was to evaluate the effect of genetic and non genetic sources of variations on lactation yield in Sahiwal cows maintained at Uttar Pradesh Livestock- cum- Agriculture Farm, Chak Ganjaria, Lucknow, U.P. Data comprising a total of 2985 records on lactation yield spanning over a period of 62 years (1949 to 2011) were analysed by least squares analysis using suitable statistical model. The overall least squares mean for total lactation yield was found to be 2069.2280.69 kg.Lactation yield was significantly influenced by sire (P<0.01), period of calving (P<0.01), season of calving (P<0.05) year and parity (P<0.05). The heritability for total milk production was estimated to be 0.105±0.035 and breeding values of sires ranged from − 121.38 to 103.69. Genetic, phenotypic and environmental trends for lactation yield were −4.46, −116.26 and −111.80, respectively.