草鱼对饲料中磷需要量的研究

采用酪蛋白—明胶(7:1,W/W)为基础的精制饲料,以磷酸二氢钙作磷源,用梯度法进行草鱼对饲料中磷需要量的试验,证实草鱼的生长受饲料中磷含量的影响较大。饲料中磷不足,草鱼生长缓慢,饲料系数高,整条鱼体水分、灰分、钙、磷和钙磷比低下,脂肪积累,脊椎骨磷含量低下。饲料中磷含量过高引起草鱼生长缓慢,甚至死亡。根据鱼的增重率、饲料系数等分析判断:草鱼饲料中磷的适宜范围为0.95—1.10％,草鱼对饲料中有效磷的需要量为0.85—1.00％。试验表明:草鱼饲料中的盐类添加应以磷为主体。

REQUIREMENT OF PHOSPHORUS IN DIETARY OF GRASS CARP

An experiment on requirtment of phosphorus in the dietary ofgrass carp Ctenopharyngodon idellus was catrried out. By the use of casein-gelatin asbasic diet with mono calcium phosphorus as source of phouphorus, the gradientmethod was applied. The results of the experiment demonstrated that the dietaryphosphorus played a great effect on the growth of grass carp. The deficiency ofphosphorus in the diet would cause a slow growth of the fish and high expense offood. By analysing, the whole fish body contains a lower level of water, ash, calcium,phosphorus and Ca/P ratio, but high content of fat with low phosphorus in vertebrae.The over-high phosphorus, however, would also result in slow growth of the fishand even lead to mortality. Thus judging from the growth rate and food consumptionof the fish, the appropriate value of phosphorus in the grass carp diet should be0.95--1.10% and the requirement of available phosphorus in the diet of grass carp is 0.85--1 .00%. The experiment indicated that phosphorus should be the principalmineral in the additive of diet.