Derivation of regression equations for body weight prediction from body Morphometry in Murrah buffalo (Bubalus bubalis)

Abstract

Accurate body weight assessment is indispensable for efficient livestock management, yet direct weighing of buffaloes in field conditions remains logistically impractical for most smallholder farmers. The present study was undertaken to derive first-order and second-order polynomial regression equations for predicting body weight (BW) from easily measurable body morphometric traits in Murrah buffaloes across varied age groups, sexes, and physiological states. A total of 227 Murrah buffaloes maintained at the Cattle and Buffalo Farm, LPM Section, ICAR-IVRI, Izatnagar, Uttar Pradesh were examined. Five morphometric traits — body length (BL), heart girth (HG), barrel girth (BG), height at shoulder (HAS), and height at tail (HAT) — were recorded and correlated with actual body weight. Heart girth and barrel girth consistently emerged as the most strongly correlated predictors across the majority of age-sex categories. A general second-order polynomial equation applicable across all animal categories was derived: BW = 179.39 + 4.23×HG-6.84×BG + 0.02×HG² + 0.04×BG²-0.04×HG×BG, achieving an R² of 0.96. Category-specific second-order equations recorded R² values from 0.74 to 0.99. These regression equations offer practical, low-cost instruments for field-based BW estimation in Murrah buffaloes, with direct utility for feed management, health monitoring, genetic selection, medication dosing, and optimal breeding decisions.