Study on Growth Fitness Models of the F1 Lambs of Poll Dorset and Qinghai Semi-Fine Wool Sheep in Qinghai Plateau

The early growth process of both crossbred F1 lambs of Poll Dorset and Qinghai Semi-Fine Wool Sheep and lambs of Qinghai Semi-Fine Wool Sheep was studied by fitting of Gompertz and Logistic models,The results showed that the fitnesses(R2) of two models were above 0.98,of which the Gompertz model had both higherR2 value and better prediction effectiveness of body weight.As a result,Gompertz model was used to estimate the parameters of maximum body weight,inflection agebody weight at inflection age,instantaneous relative growth rate(K),relative growth rate(RGR) and instantaneous growth rate(GR).Consequently,the crossbred F1 lamb grows more rapidly than that of Qinghai Semi-Fine Wool Sheep.