Applications Of Azomite, Protease And Citric Acid In Feed Of Grass Carp(Ctenopharyngodon Idella)

An experiment was conducted to investigate the effect of supplementation of AZOMITE on growth performance, intestinal digestive enzyme activities and serum nonspecific immune of grass carp(Ctenopharyngodon idella). Four diets adding respectively 0% (control group), 0.2%, 0.3%, 0.4% AZOMITE were fed to grass carp with initial body mass of(64.20±1.68)g for 8 weeks. The results showed that growth performance of grass carp were increased in different degrees by supplemental AZOMITE in diets, in which weight gain (WG) was increased by 16.65%(P=0.08)and feed conversion rate (FCR) was decreased by 12.90%(P<0.05)by supplementation of 0.2% AZOMITE in diet compared with control group. Condition factor (CF) of fish fed with diet containing 0.2%, 0.4% AZOMITE were significantly higher than control fish(P<0.05). There was no significant difference in the content of muscle moisture, ash, crude fat and crude protein among treatments(P>0.05). Activities of protease, lipase, amylase in intestine and superoxide dismutase (SOD) , alkaline phosphatase(AKP) in serum of fish were enhanced in different degrees(P>0.05)by addition of 0.2%-0.4% AZOMITE in diet. Fish fed with diet containing 0.2% AZOMITE had a significantly higher SOD activity than control fish(P<0.05). Hepatopancreas GOT and GPT activities were not affected by 0.2%, 0.3% AZOMITE addition, but significantly decreased by 0.4% AZOMITE addition. Results of above show that the addition of AZOMITE could improve the growth performance and serum nonspecific immune function. The proper dose of AZOMITE in grass carp diet was suggested to be 0.2%. A 8-week feeding experiment was conducted to investigate the effects of protease PT, citric acid and AZOMITE on growth performance, intestinal digestive enzyme activities and serum biochemistry indexes of grass carp(Ctenopharyngodon idella) with initial body weight of(31.99±0.05). The basal diet was applied as control, in which 175mg/kg protease PT, 0.3% citric acid and 0.2% AZOMITE were added into basal diets as test diets, respectively. The results showed that: The weight gain (WG) in each group were 332.92%,363.0%,363.02% and 346.87%, respectively, the feed conversion rate (FCR)were 1.19,1.09, 1.10 and 1.15, respectively. Compared with control, the WG of in the group of protease PT increased by 9.04% (P<0.05) while FCR decreased by 8.40 %( P<0.01), the WG in the group of citric acid increased by 9.04% (P<0.05) and FCR decreased by 7.56 %( P<0.05). Diets supplemented with AZOMITE could also improved the fish WG and FCR to a certain extent but had no significant effect (P>0.05).No significant difference of moisture, ash, crude fat and crude protein in muscle were observed among the groups (P>0.05). Activities of protease in intestine and activities of SOD , AKP in serum of fish were significantly improved by adding protease PT in diets compared to control (P<0.05), adding citric acid could increased the activities of lipase, SOD and decreased the concentration of BUN (P<0.05). However, SOD, AKP and BUN in serum of fish were improved in varying degree by adding AZOMITE in diets but no significant effect were observed (P>0.05). Results of above show that diets supplemented with protease PT, citric acid could improve the growth performance, intestinal digestive enzyme activities and serum nonspecific immune function.