Asian-Australasian Journal of Animal Sciences
- Volume 10 Issue 1
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- Pages.70-74
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- 1997
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- 1011-2367(pISSN)
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- 1976-5517(eISSN)
DOI QR Code
Definition of Season in Animal Model Evaluation of NiIi-Ravi Buffaloes
- Khan, M.S. (Faculty of Animal Husbandry, University of Agriculture) ;
- Bhatti, S.A. (Faculty of Animal Husbandry, University of Agriculture) ;
- Asghar, A.A. (Livestock Production and Research Institute) ;
- Chaudhary, M.A. (Livestock Production and Research Institute) ;
- Bilal, M.Q. (Faculty of Animal Husbandry, University of Agriculture)
- Received : 1996.05.27
- Accepted : 1996.10.17
- Published : 1997.02.01
Abstract
Data on 2,571 lactation records of Nili-Ravi buffaloes from four institutional herds and four field recording centers were analyzed under an animal model to see the effect of season definition on the error variance of the fitted model. Herd-year-season(HYS) was the main fixed effect along with permanent environment, breeding value and residuals as the random effects. All known relationships among the animals were considered. The error variance differed for various HYS combinations. It was minimum when then months were not grouped into seasons. The four or Five season scenarios were better than the two season scenarios. The average number of lactations represented in a HYS combination varied widely from 6 to 28. Very few subclasses for a given HYS combination warrants the use of fewer seasons for animal model evaluation of buffaloes.