Estimation of growth curve characteristics of Hemsin male and female sheep

摘要

In the present study, we examined the suitability of seven asymptotic nonlinear models to describe body weight growth of Hemsin male and female sheep from birth to 36 months of age and, using the selected functions, to provide a biological interpretation for this growth. The weight?￠????age data for this study were obtained from records of 108 Hemsin female and male sheep held in variety breeder flocks of Artvin province in Turkey. The sheep records were collected between 2008 and 2010 with measurements taken at birth, 2nd, 3rd, 6th, 12th, 18th, 24th, and 36th months of age. Body weight?￠????age data from Hemsin sheep were used to obtain a growth pattern for sheep, with the use of Negative exponential, Brody, Gompertz, Logistic, Bertalanffy, Richards, and Janoschek nonlinear functions. Comparisons between these functions were based on coefficients of determination and residual squared error. The R 2 values of the models ranged from 0.971 to 0.989 for males and from 0.951 to 0.991 for males. In both sexes, the Brody, Richards, and Janoschek models, with equal R 2 as 0.99, were superior to the others. However, the Brody was precise on its parameters and easy to interpret than Richards and Janoschek functions.