Effects Of Attractant Complex On Growth,Immune Indexes And Digestive Enzymes Of Gift Tilapia

With the rapid development of aquatic industry in China,the increasingly scarce protein feed resources have become the limiting factor.In order to solve this problem,domestic feed enterprises and scientific research institutions are exploring new and cost-effective animal and plant protein sources.However,adding low-priced plant protein sources to the feed will lead to poor feed intake and low feed utilization.At present,the exploration of new attractants complex plays an important role in improving the attractiveness,palatability and feed conversion rate of feed.In order to study the effects of adding attractant complex A(mainly composed of allicin,dimethyl-?-propionate,trimethylamine oxide,and starch)or attractant complex B(mainly composed of taurine,arginine,glutamic acid,alanine,glycine,nucleotides,starch compounded amino acid composite attractant)at different concentrations in feed on growth,immune indicators and the activity of intestinal digestive enzyme,thirty hundred and seventy five fish with similar health,body length,and weight were selected for this test.They were randomly divided into 5 treatments,each with 3 replicates,each replicate.25 fish.The first treatment group was a control group,and the diets of treatment groups 2 and3 were added with 0.1% and 0.2% of attractant complex A,respectively,and the treatments of groups 4 and 5 were added with 0.1% and 0.2% of attractant complex B,respectively.The results show as follow:1.The growth results showed that compared with the control group,the 0.2% attractant complex A group significantly increased the growth,feed intake,specific growth rate and relative weight gain rate(P < 0.05).The 0.2% attractant complex B significantly reduced the feed conversion rate of tilapia(P <0.05).2.The results of health indicators showed that there was no significant difference between the experimental groups in terms of fullness and hepatopancreas index(P> 0.05).However,the fullness index of the group treated with 0.2% attractant complex A was slightly higher than other groups.At the same time,the hepatopancreas index of the test group with added attractant was slightly lower than that of the control group;the visceral ratio index of the control group was significantly higher than that of the test group with 0.2% compoundattractant A and 0.2% compound attractant B(P <0.05).3.The results of whole fish composition showed that the crude protein content of the0.2% complex attractant B was significantly higher than that of control group(P <0.05).4.The results of serum biochemical and immune indicators showed that the four treatment groups with adding attractant had no significant differences in blood glucose,uric acid,and total serum protein indicators compared with the control group(P> 0.05).However,the total protein content of serum after adding compound attractant was higher than that in control group;in terms of the total triglyceride index,the test group added attractant complex was significantly lower than that in control group(P <0.05).In terms of total cholesterol,the test group added compound attractant A was significantly lower than that in control group(P<0.05).There was no significant difference in terms of aspartate aminotransferase and alanine aminotransferase(P> 0.05).5.In the SOD indicator,the 0.2% complex attractant A was significantly higher than that in control group(P <0.05).In terms of lysozyme index,the 0.2% complex attractant A was significantly higher than that in control group(P <0.05).6.The activities of intestinal digestive enzyme showed that the activities in fish fed adding attractant complex B was higher than that of all other groups.Among them,the 0.2%complex attractant B had the strongest vigor.In summary,the addition of 0.2% compound attractant A in diet can significantly increased the feed intake,specific growth rate and relative weight gain rate of Gift tilapia,and significantly increased the serum lysozyme content of Gift tilapia.As well as the activity of intestinal digestive enzymes and serum SOD was improved.The 0.2% compound attractant B reduced the feed conversion rate of tilapia,significantly increased the activity of intestinal digestive enzymes,and significantly increased the crude protein content.Based on the above indicators,compound attractant A has a better effect on the healthy growth of tilapia than compound attractant B,but in terms of reducing the feed coefficient,compound attractant B has a better effect than compound attractant A.