Prediction of first lactation 305 day milk yield from monthly test day milk yield using multiple linear regression model in Jaffarabadi buffaloes

Abstract

The records first lactation monthly test day milk yields of 213 Jaffarabadi buffaloes spread over a period of 24 years (1991 to 2014) maintained at Cattle Breeding Farm, Junagadh Agricultural University, Junagadh were used to predict first lactation 305 day or less milk yield using multiple linear regression model with backward elimination procedure. The data were collected at 30 days interval from 4^th day till 304^th day post calving. The accuracy of prediction model was calculated by estimating R²-value. Analysis carried out revealed that when all the monthly test day records (1 to 11) were incorporated in an equation to predict first lactation 305 day or less milk yield, the accuracy (R²-value) was maximum with 97.06%. However, early best prediction of 305 days milk yield based on monthly test day milk yields was found up to 6^th monthly test day milk record. The optimum equation had total four variables viz. 2^nd, 4^th, 5^th and 6^th monthly test day milk yield records, which gave an accuracy of prediction of 78.28%. Therefore, it is concluded that first lactation 305 days smilk yield could be predicted as early as 6^th month of lactation with higher degree of accuracy.