The Effects Of Different Starchin Expanded Feeds On Growth And Biochemical Indexes Of Large Scale Grass Carp

This study was conducted to investigate the effects of different starchsource on growth performance and biochemical indexes of large scale grass carp(400±20 g),in terms of growth and feed cost.Based on these studies,it was aimed to provide theoretical basis for developing efficient,environmental and safe compound feed for large scale grass carp,seek suitable starch source for large scale grass carp,eventually compensating the nutritional standard of large scale grass carp.Five isonitrogenous and isoenergetic diets containing different starch source(wheat,barley,corn,sorghum,cassava)were randomly allocated to triplicate groups of fish and the experiment lasted four months.The results were summarized as follows:1.The weight growth rate(WGR)of large scale grass carp fed diet with corn was the lowest(P<0.05)and the cost of per weight gain was the lowest in cassava group.Blood glucose of fish fed the diet with wheat was significantly lower than that in other treatments(P<0.05).Cholesterol of fish fed diets with barley and sorghum were significantly higher than that in wheat group(P<0.05).Triglyceride of fish fed diets with barley was significantly higher than that in wheat group(P<0.05).The amylase,trypsin and lipase activities of cassava group were significantly higher than wheat group(P<0.05),amylase and trypsin activities of sorghum group were significantly lower than wheat group(P<0.05).The GPT and GOT activities of wheat group were significantly higher than other treatments(P<0.05).The hepatic glycogen contents of cassava group were significantly higher than wheat group(P<0.05),the muscle glycogen contents of barley and cassava groups were significantly higher than wheat group(P<0.05),com group's muscle glycogen was significantly lower than wheat group(P<0.05).In conclusion,with growth index as evaluation standard,cassava was the most suitable type carbohydrate for large grass carp;with feeds' economic benefit as evaluation,under the condition of sane adding proportion,cassava was the most suitable type carbohydrate for large scale grass carp;with physiological and biochemical indicators and visceral injury degree as evaluation,the most suitable type carbohydrate for large scale grass carp was cassava.Taking all various indicators into consideration,suitable sorting of five different types of carbohydrate was:cassava>wheat>barley>sorghum>corn.2.After the winter,the expanded feeds with different starch source resulted in a certain decline on weight,condition factor,visceral somatic index,crude protein of muscle,crude lipid of muscle,blood glucose and blood lipid of large scale grass carp.However,there were no significant differences between dietary treatments.Before and after the winter,the weight drop of barley group was the highest and significantly higher than wheat group(P<0.05).The visceral somatic index drop of the corn group wassignificantly higherthan barleygroup(P<0.05).The hepatopancreas visceral somatic index drop of the cassava group was significantly higher than wheat group(P<0.05).The drop of muscle lipid was higher than muscle protein in all treatments,but there is no significant difference.The serum triglycerides drop in cassava group was the lowest,but there was no significant difference between cassava and wheat groups(P>0.05).In conclusion,with body weight change as evaluation standard,sorghum was the most suitable type of carbohydrate for large scale grass carp.