Comparative efficiency of different multiple linear regression prediction equations of first lactation 305-day milk yield for sire evaluation in Murrah buffaloes Sahoo Saroj Kumar1,*, Singh Avtar, Ambhore G.S.2, Dash S.K.1, Dubey P.P.1 ICAR-National Dairy Research Institute, Karnal-132 001, Haryana, India 1Department of Animal Genetics and Breeding, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Science University, Ludhiana-141 012, Punjab, India 2Cattle Breeding Farm, Igatpuri, Maharashtra Animal and Fishery Sciences University, Nagpur-440 006, Maharashtra, India *Corresponding author's e-mail: sarojvet6804@gmail.com
Online published on 16 November, 2019. Abstract In this study, first lactation 39059 weekly test-day milk yield records of 961 Murrah buffaloes were used to predict first lactation 305-day milk yield (FL305DMY) by stepwise backward regression method. The best single, two, three and four test day combinations wereselected for prediction of FL305DMYbased on adjusted R2 and RMSEvalues. The sires were evaluated for 305-dayactualand predictedfirst lactation milkyield based on derived multiple regressionequations using four methods viz. least squares (LSQ), simple regressed least squares (SRLS), best linear unbiased prediction sire model (BLUP-SM) and best linear unbiased prediction animal model (BLUP-AM) methods. The effectiveness of different sire evaluation methods were judged by error variance, coefficient of determination, coefficient of variation and spearman's rank correlation. The accuracy of prediction of FL305DMY from weekly test day milk yields were observed to be best for TD-7 (48th day) and TD-22 (153rd day) combination with BLUP-AM as the most efficient method for sire evaluation. It was concluded that the FL305DMY can be predicted as early as 153rd dayof lactation and further can be used for earlygenetic evaluation of Murrah sires. Top Keywords FL305DMY, Murrah buffalo, Sire evaluation, Stepwise backward regression, Weekly test-day. Top |