Modeling Lactation Curve for Test Day Milk Yields in Holstein Friesian Crossbred Cattle

Rohit Gupta; Saroj Kumar Sahoo; Simarjeet Kaur; Shakti Kant Dash; Puneet Malhotra

doi:10.5455/ijlr.20200618053135

Authors

Rohit Gupta M.V.Sc., Department of Animal Genetics and Breeding, GADVASU, Ludhiana, Punjab, INDIA
Saroj Kumar Sahoo Assistant Animal Geneticist, Department of Animal Genetics and Breeding, GADVASU, Ludhiana, Punjab,
Simarjeet Kaur Animal Geneticist, Department of Animal Genetics and Breeding, GADVASU, Ludhiana, Punjab,
Shakti Kant Dash Assistant Professor, Department of Animal Genetics and Breeding, GADVASU, Ludhiana, Punjab, INDIA
Puneet Malhotra Dairy Manager, Department of Animal Genetics and Breeding, GADVASU, Ludhiana, Punjab, INDIA

DOI:

https://doi.org/10.5455/ijlr.20200618053135

Keywords:

Holstein Friesian, Lactation Curve, Monthly Test Day, R2, RMSE

Abstract

The present study was conducted on first lactation monthly test day milk yield records of 466 Holstein Friesian× Sahiwal crossbred cattle maintained at Directorate of Livestock Farms, GADVASU, Ludhiana. Four mathematical models viz. Mixed Log (MLF), Exponential (EF), Inverse Polynomial (IPF) and Polynomial Regression functions (PRF) were compared for monthly test day milk yield records. The adjusted R2 values of these functions were 88.80, 86.68, 99.90 and 99.31%, respectively; whereas the root means squares error (RMSE) with these functions were 0.161, 0.176, 0.172, and 0.035 kg, respectively. The PRF was adjusted best fit based on adjusted R2 and root mean squares error (RMSE) values. The best fit lactation curve functions will be helpful for milk yield prediction as well as genetic evaluation and selection of superior sires using records of their daughters.