Prediction of first lactation total milk yield using part lactation performance trait in Hariana cattle

The present investigation was undertaken to develop prediction models for first lactation total milk yield (FLTMY) in Hariana cattle using lactation and reproductive traits. The study utilised first-lactation performance records of Hariana cows maintained at the Livestock Farm Complex, DUVASU, Mathura, during the period 1964 to 2025. Age at First Calving (AFC), first lactation length (FLL) and 30-days milk yield (30DMY) were considered as predictor variables, while FLTMY served as the dependent trait. Multiple linear regression models were developed using different combinations of predictor traits. Model performance was evaluated using coefficient of determination (R²), root mean square error, mean absolute error, mean absolute percentage error and Theil’s U statistic. Multicollinearity among predictors was examined through variance inflation factor values, which indicated absence of serious collinearity. Among seven models developed, the model including FLL and 30DMY proved most efficient, explaining 64.65 per cent variation in FLTMY with lower error statistics. Although the three-trait model showed marginally higher R², the two-trait model was preferred for simplicity and practical utility. The final prediction equation developed was FLTMY=-620.93 + 4.63(FLL) + 3.82(30DMY).