五龄饲育温度对家蚕营养代谢及饲料效率的影响——Ⅱ.对饲料粗蛋白质的摄取和利用的影响

本试验调查了在不同饲育温度条件下,五龄对桑叶粗蛋白质的食下消化,蛋白质的异化代谢及留存分配等情况,探讨了五龄饲育温度对蛋白质利用率的影响。初步结果为:在20℃-30℃范围内,较低温度使发育减慢,龄期延长,从而使蛋白质的食下量,消化量增多;20℃区的蛋白质平均消化率为64.32％,比30℃区高2.3％,达显著差异水平。蛋白质的异化代谢似乎不受饲育温度的影响,各温度区的蛋白质消费率大致相仿,留存率均在90％左右。较低温度使留存蛋白较多地分布于茧层,而较高温度使蛹体蛋白含量增高,差异达显著水平。30℃区的食下蛋白的茧层转化率为35.58％,20℃区则为38.03％。五龄期偏低温度饲育较明显地提高了蛋白质利用率。

Influnces of different rearing tem-perature in the 5th instar on the nutrional metabo-lism and dietary efficiency: I . On the digestion and utilization of crude protein in the diet. Sci.

In this experiment it was investigated that influnces of different rearing temperature in the 5th instar larvae of the silkwom on digestion, catabolism and residual distribution of crude protein in the mulberry leaf.The preliminary testing results were as follow; (1) In the experimental plot at 20C, average of the digestibility of the protein was 64.32% that was higher about2.3% than plot at 30C, the difference had the satistical significance. < 2 ) Catabolism of the protein almost wasn't influnced with rearing temperature, protein consumptive rate of each experimental plot was similar. ( 3 ) Larvae rearing at lower temperature made reserving protein distribute more over cocoon shell, while rearing at a higher temperature was able to raise the protein content in the pupal body was significantly higher. ( 4 ) In the testing plot at 30C, percentage of cocoon shell weight of digesting protein was 35.58%, but at 20% was 38.03%. Thus, using a lower rearing temperature could raise the utilising rate of proteins.