海狸鼠体重、体长及消化系统的生长发育研究

STUDY ON THE GROWTH AND DEVELOPMENT OF BODY WEIGHT,BODY LENGTH AND DIGESTIVE SYSTEM OF NUTRIA

测定了不同时龄海狸鼠的体重、体长、肠道长度及胃和盲肠的最大容积。其结果为，海狸鼠体重的生长发育高峰在１２０日龄，体长的生长高峰在９０日龄，体长的增长要慢于体重的增长，２４０日龄时体重为初生重的１８．７５倍，体长仅为初生时的４．２３倍。小肠的长度自出生便迅速生长，这种快速生长一直持续到４５日龄左右，但其生长系数不大，这说明小肠在胚胎时期已发育到较成熟的程度；盲肠容积的生长在６０～１２０日龄最快，１２０日龄时为初生时的１０倍左右，２４０日龄仅为初生时的１３倍；胃的生长发育比盲肠的生长慢，２４０日龄时的最大容积为初生时的５．５倍，且生长集中于０～１２０日龄。体重与体长、体重与消化道各指标间的相关系数均大于０．９６，并建立了以体重为自变量，其它指标为依变量的９个回归方程。

The body weight,body and food tube length and the largest volume of stomach and blind gut of nutria ( Myocastor coypus ) at different ages were measured. The results showed that:The growth and development peak of body weight and body length appeared at 120 days and 90 days respectively,the rate of growth of body length was slower than that of the boby weight, the body weight of 240 days was as 18.75 times as birth weight, the body length was only as 4.23 times as birth length. Although the small instestine length grew fast from birth to 45 days, the coefficient of growth of it wasnt large, this showed that the small instestine had been more fully developed at the embryonic period. The growth of blind gut volume was the largest at 60 days to 120 days ,blind gut volume at 120 days and 240 days were about as 10 and 13 times respectively as that of birth, the growth of stomach volume was slower than that of the blind gut, the largest volume of stomach at 240 days was as 5.5 times as that of birth, the growth of it was mainly at 0 to 120 days. The coefficient of correlation of body weight and body length, all characters of digestive system were over 0.96, the 9 regression equations were established based on body weight as independent variable and the others as dependent variable.