ENVIRONMENTAL FACTORS AFFECTING MILK YIELD IN FRIESIAN COWS IN PUNJAB, PAKISTAN

University of Veterinary and Animal Sciences, Lahore,
¹Livestock Production Research Institute, Bahadurnagar, Okara,
²Research Institute for Physiology of Animal Reproduction, Bhunikey (Pattoki) Distt. Kasur, Pakistan

Abstract   

    Data on 823 performance records of 537 Friesian cows maintained at the Livestock Experiment Station Bhunikey (Pattoki) District Kasur during the years from 1984 to 2001 were used to investigate various sources of variation for milk yield. The Harvey’s least squares analysis was carried out. The least squares means for milk yield and lactation length were 3391.66 ± 137.97 kg and 278.40 ± 90.17 days, respectively. The two traits were significantly correlated with each other having a correlation coefficient of 0.61 (P<0.01). Lactation length and lactation number were significant (P<0.01) sources of variation for milk yield. The influence of year and season of calving on milk yield was also significant (P<0.01). The milk yield was the highest (3659.48 ± 153.47 kg) among the cows calving during autumn and the lowest (3249.36 ± 151.83 kg) among those calving during humid hot season. The cows calving during spring, winter and dry hot seasons yielded 3424.38 ± 188.16, 3345.91 ± 140.12 and 3279.18 ± 201.29 kg of milk, respectively.    

Key words: Friesian cows, milk yield, season, parity.