Estimation of Growth Curve Parameters Using Non-Linear Growth Curve Models in Sonadi Sheep

Abstract

Sonadi sheep rearing is an important livelihood for a large number of small and marginal farmers in Southern Rajasthan. Growth, defined as changes of body weight over time is an economically important trait in sheep that directly determines meat production. The present study was aimed to estimate the growth curve parameters for live-weight from birth to 12 months age in Sonadi sheep. Data on 56 Sonadi sheep, including 28 males and 28 female which were born in year 2016 maintained at Mega Sheep Seed Project, Vallabhnagar, Udaipur were used. Non-linear growth models, viz. Gompertz, Brody, negative exponential, logistic and Von Bertalanffy were used for estimating the growth curve parameters. Average of live weight (Kg.) in Sonadi sheep from birth to 12^th month of age were 3.27±0.081, 6.72±0.202, 9.06±0.267, 12.19±0.388, 15.01±0.44, 16.21±0.51, 16.75±0.54, 18.54±0.586, 18.59±0.599, 20.86±0.586, 21.51±0.517, 22.10±0.522 and 23.15±0.512, respectively. The value of growth parameters for lamb from Brody model; “A”, “B” and “K” were 26.033±1.109, 0.872±0.016 and 0.160±0.018, respectively. Adjusted determination coefficient (R²_adj), RMSE and AICc were 0.991, 0.599 and – 5.08, respectively. As a result of highest R²_adj and lowest RMSE, AICc, Brody model can be said an appropriate model for drawing growth curve.