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Lactation Curve Modeling for Murrah and Surti Buffalo Breeds in Sri Lanka
ABSTRACT: Lactation curves are useful in deriving complete lactation records for genetic selection from incomplete records which is a common problem in dairy buffaloes in Sri Lanka. A data set of 12,518 monthly lactation records of purebred Murrah and Surti cows from seven government farms in Sri Lanka were used to model lactation curves. The models proposed by Gaines, Wood, Rook and Dijkstra were fitted using nonlinear regression procedures. With only two parameters, the Gaines’s model failed to provide a satisfactory fit. Rook’s model provided the best fit for both breeds, while the Dijkstra’s model was the second best. Thus, a four parameter mechanistic model such as Rook’s model can be recommended for lactation curve modeling of buffaloes in Sri Lanka. The performance levels of both breeds showed the need for improvement in management standards in addition to genetic improvement.
Keywords:
Buffalo
modeling
Lactation curve
