Utilization Of Sunflower Meal And Three Kinds Of Cottonseed Meal With Different Protein Contents In Diets For Grass Carp (Ctenopharyngodon Idella)

Using grass carp as the test objects, four plant protein materials—general cottonseed meal (GCM), high-protein cottonseed meal (HCM), degossypolled cottonseed meal (DCM) and sunflower seed meal (SSM) were used in practical feed formulation. In the test, each formula was designed with low and high levels (high level increased by 45% compared with low level), eight grass carp formulas were designed while the levels of protein, fat and energy were consistently. Each formula was made by two different feed processing methods into expanded feed and hard pellet, and there were 16 tests in total. Grass carps were divided into 16 groups randomly; each group had 3 parallel tests. Grass carps were fed in net cage for 62 days. At the end of breeding, growth rate, feed efficiency, some physiological and biochemical indexes, and amino acid composition of grass carps were analyzed in order to study the practical application effect of four plant protein materials and their combinations in the formula of grass carp.The results showed that:1. GCM, HCM, DCM and SSM in the feed had significant effect on the growth rate of grass carp (P<0.05). The specific growth rate of DCM group was 1.8%/d, it was significantly lower than other groups (P<0.05). Feed conversion ratio(FCR) and protein efficiency of grass carp were not significantly different (P>0.05) between different groups. Under the same formulation system, the feed processing technology had no significant effect(P>0.05) on the specific growth rate of grass carp. However, the specific growth rate, feed conversion ratio, and protein efficiency of grass under two processes of the same raw material were significantly different (P <0.05).2. The effect of four plant protein materials on SOD, GSH-Px enzyme activity and MDA content in liver tissue of grass carp showed significant differences (P<0.05), but it had no significant effect on DAO in serum, D-lactic acid (P> 0.05).3. The apparent digestibility of histidine, methionine and isoleucine were significantly different (P<0.05). Under the same feed formulation system, intestinal amino acids composition and the apparent digestibility of essential amino acids of grass carp were not significantly different between expanded feed group and hard pellet group(P <0.05).4. The test feeds had no significant effects (P<0.05) on amino acids composition of whole fish, muscle and hepatopancreas of grass carp (P<0.05). The combination of raw materials had no significant effect (P>0.05) on intestinal amino acids composition and the apparent digestibility of essential amino acids of grass carp.In summary, the measured results such as apparent digestibility of feeds, specific growth rate, feed conversion ratio, antioxidant stress index of blood, intestinal permeability index and the amino acid composition of grass carp showed that:①GCM, HCM, DCM and SCM could be used in the expanded feed and hard pellet feed of grass carp, and achieved good growth results.②Two levels (22% and 32% of GCM, 18.5% and 26.5% HCM, 15.5% and 25.5% of DCM, 22% and 28% of SCM) of the same material were not affected the health growth of grass carp.③GCM and DCM were more conducive to the growth of grass carp when processed into expanded feed. HCM was more conducive to the growth when processed into hard pellet. Two processing technology of SSM had no significant effect on the growth of grass carp .