Prediction equation for estimating live body weight of dromedary calves

Abstract

Prediction of live body weight of dromedary calves was attempted through regression models utilising the body dimensions viz. body length, heart girth and height at withers. A total of 46 neonatal dromedary calves of 4 dromedary genotypes comprising 30 males and 16 females were measured up to 14 weeks of age. The breed and sex associated differences were non-significant (P>0.05). Eleven regression models viz., linear, logarithmic, inverse, quadratic, cubic, compound, power, S, growth, exponential and logistic and the three body dimensions were utilised. Heart girth appeared as the most reliable predictor of the body weight at this stage of life. The power regression equation gave the best fit (R2 = 0.92) for the unique measurement of heart girth. Efforts were also made to derive the coefficients utilising the mean values and it was observed that most of the regression models explained the variability to the extent of ≥ 99%. The quadratic equation Ŷ= 18.9162 -0.6845 HG + 0.011645 HG2 and power equation Ŷ = 0.0008684 (HG2.44333) explained the variability to the extent of 99.7% and may be used for the precise estimation of body weight during early months of the life. However, looking at the requirement of estimation of unique live weight, it is recommended that the power equation Ŷ = 0.0008684 (HG2.44333) may be used as the most reliable one by the scientists, veterinarians and animal husbandry men for all practical purposes.