豫北小尾寒羊生长模型的拟合与分析

【目的】为了掌握豫北地区小尾寒羊的生长发育特点，认识其生长发育的规律。方法】选择3月龄断奶羔羊公母各30只，进行跟踪体重测量，直到24月龄为止；拟合了Logistic、Gompertz和vonBertalanffy生长曲线，计算了绝对生长和相对生长指标。【结果】表明：三种模型均能较好地描述豫北小尾寒羊的生长过程，拟合度均在0．95以上，但VODBertalanffy模型更符合实际饲养情况，模拟效果更好（公母羊的R2分别为0．9730和0．9764）；公母羊相应的体重极限参数A分别为113．717和71．814，调节参数B分别为0．534和0．464，瞬时相对生长率分别为0．074和f）．094；公羊和母羊的生长拐点日龄分别为191．01d和105．39d，拐点体重分别为33．694kg和21．278kg，最大日增重分别为124．668god-1和100．008god～1。【结论】VOFIBertalanffy模型在模拟3～24月龄豫北小尾寒羊生长状况方面为理想的数学模型，母羊比公羊早熟性更好，绝对生长和相对生长均符合生长发育的一般规律，此研究结果可作为饲养管理和选育改良的重要参考。

Analysis and Fitting on Growth Model of Yubei Small-tail Sheep

Objective ] In order to grasp characteristics of growth and development of yubei small-tail sheep, and understanding its regulation. method] Choice male lamb and female lamb 30 for each. The bodyweight of yubei small-tail sheep form 3 to 24 months old was measured. The growth curve was fitted with Logistic, Gompertz and yon Bertalanffy, three kinds of nonlinear models. The absolute growth and the opposite growth were calculated. Results ] The results showed that growth process of yubei small-tail sheep could be demonstrated fairly good by three models, and all indexes of fitness were very high （more than 0.95）. But yon Bertalanffy model was the best model （male and female lamb＇s R2 were 0.9730 and 0.9764 respectively）, because of its less bias of feed practice. Male and female lamb＇s body weight extreme limit parameter A were 113.717 and 71.814, adjustment parameter B were 0.534 and 0.464, transient relative growth rates were 0.074 and 0.094, the inflection age of growth curve were 191.01 days and 105.39 days, bodyweight at the inflection age were 33.694kg and 21.278kg, max weight increment were 124.668g/d and 100.008g/d, respectively on the growth model. Conclusion ] The von Bertalanffy model was the ideal mathematical model on the growth of yubei small-tail sheep form 3 to 24 months old. The male lamb was better than the female lamb ram early maturity. The absolute growth and the opposite growth conform to the growth general rule. These results could be used in feeding yubei small-tail sheep scientifically and breed selectively im- provement.