A suitable prediction model of body weight and trait measurements of Lanzhou fat-tailed sheep

Lanzhou fat-tailed sheep are an excellent local livestock genetic resource. This study investigated the growth and development patterns of Lanzhou fat-tailed sheep. Three models were screened for accuracy to fit growth curves for body weight and trait measurements in female Lanzhou fat-tailed sheep from birth to 24 months of age. The results showed that the Von Bertalanffy model was the optimal growth curve model for this species. The inflection point for weight growth of female Lanzhou fat-tailed sheep was 2.40 months old (18.77 kg) and that for chest circumference growth was 1.64 months old (30.67 cm). Growth pattern analysis revealed that the fastest growth and development period of female Lanzhou fat-tailed sheep was at 2 to 4 months. After 4 months, the development rate of weight and trait measurement decreased gradually with the increase in monthly age. The results showed that female Lanzhou fat-tailed sheep possessed significant advantages of rapid growth and development at an early stage with a high weight gain rate; thus, they are an excellent germplasm resource for developing the sheep industry in arid and semi-arid areas of northwest China. This study can provide a theoretical basis for the conservation and innovative use of genetic resources of Lanzhou fat-tailed sheep.