Environmental factors affecting milk yield in Friesian cows in Punjab [Pakistan]
2004
Javed, K. (University of Veterinary and Animal Sciences, Lahore (Pakistan)) | Afzal, M. | Sattar, A. | Mirza, R.H.
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 plus minus 137.97 kg and 278.40 plus minus 90.17 days, respectively. The two traits were significantly correlated with each other having a correlation coefficient of 0.61 (P less than 0.01). Lactation length and lactation number were significant (P less than 0.01) sources of variation for milk yield. The influence of year and season of calving on milk yield was also significant (P less than 0.01). The milk yield was the highest (3659.48 plus minus 153.47 kg) among the cows calving during autumn and the lowest (3249.36 plus minus 151.83 kg) among those calving during humid hot season. The cows calving during spring, winter and dry hot seasons yielded 3424.38 plus minus 188.16, 3345.91 plus minus 140.12 and 3279.18 plus minus 201.29 kg of milk, respectively.
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