Effects Of Broad Bean And Pea On Growth Performance And Flesh Quality Of Grass Carp,Ctenopharyngodon Idellus

Grass carp is an important freshwater economic fish in China.Feeding grass carp with broad bean can make the fish become “crispy”,the flesh is hardly boiled,and the flavor is unique.However,the direct feeding of broad bean is cumbersome,the workload is large,and it is contamination to the water;at the same time,the growth of grass carp is slow as well.It is necessary to develop a grass carp embrittlement formula diet.In addition,feeding pea also has a certain improvement on the muscle quality of grass carp.Therefore,this paper explored the effects of different forms of broad bean and pea on growth and flesh quality of grass carp.Exp.1 Effects of broad bean-based diets on growth performance and flesh quality of grass carpTo investigate the effects of supplemental nutrient additives in broad bean-based diet on growth and flesh quality of grass carp,five diets were prepared,including complete formula diet(Control),soaked broad bean(SBB),and three broad bean-based diets containing 80% broad bean without(BBD1)or with the supplementation of methionine(BBD2),and methionine+vitamins+minerals(BBD3),and fed grass carp(171.9±1.1)g for 84 d.The results showed that broad bean-based diets significantly increased weight gain rate(P<0.05)and reduced feed conversion ratio(P<0.05)of grass carp when compared to the SBB;the weight gain rate of the BBD3 group increased by 237.17% than the SBB group and reached the similar levels of weight gain rate and feed conversion ratio to the control group(P>0.05).Grass carp fed broad bean-based diets had lower flesh steaming water loss(P<0.05),higher muscle fiber density(P<0.05)and higher collagen contents(P<0.05)in muscle and skin than the control;particularly,the flesh steaming water loss decreased by 4.63%,muscle fiber diameter reduced by 12.90% and density increased by 31.63%,while collagen contents in muscle and skin raised by 19.30% and 12.71%,respectively,of the BBD3 group.The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in the BBD3 and SBB groups than in the other groups(P<0.05).In conclusion,the combination of methionine,vitamins,and minerals in broad bean-based diet promoted the growth of crisped grass carp,and improved the flesh quality and collagen gene expression when compared to the formula diet.Exp.2 Effects of dried and germinated broad bean-based diets on growth and flesh quality of grass carpTo investigate the effects of dried and germinated broad bean-based diets on growth performance and flesh quality of grass carp,four diets were prepared,including complete formula diet(Control),germinated broad bean(GBB),and two broad bean-based diets containing 80% dried and germinated broad bean(DBBD & GBBD),respectively,and fed grass carp(1056.1±30.3)g for 84 d.The results showed that the dried and germinated broad bean-based diets increased weight gain rate by 15.89%,17.30%(P<0.05),and reduced feed conversion ratio by 16.69%,18.00%(P<0.05)respectively,when compared to the GBB,but the weight gain rate of these two groups were still lower than that of the control group(P<0.05).When compared with the control,feeding grass carp with dried and germinated broad bean-based diets and sole germinated broad bean reduced muscle steaming loss by 25.98%,25.14% and 25.09%(P<0.05),significantly decreased centrifuge and thawing loss as well(P<0.05),increased hardness and chewiness(P<0.05),decreased muscle fiber diameter and increased density(P<0.05),and increased flesh collagen content by 26.79%,27.55%,and 28.30%,respectively(P<0.05).The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in germinated broad bean and two broad bean-based groups than in the control group(P<0.05).There was no significant difference in muscle moisture,crude protein,crude lipid,and ash contents among all treatments(P>0.05).In conclusion,dried and germinated broad bean-based diets promoted the growth of grass carp when compared to the sole germinated broad bean,and improved the flesh quality by increasing collagen content and collagen gene expression in muscle when compared to the formula diet.Exp.3 Effects of dried and germinated pea-based diets on growth and flesh quality of grass carpTo investigate the effects of dried and germinated pea-based diets on growth performance and flesh quality of grass carp,four diets were prepared,including complete formula diet(Control),germinated pea(GP),and two pea-based diets containing 80% dried and germinated pea(DPD & GPD),respectively,and fed grass carp(1056.1±30.3)g for 84 d.The results showed that the GPD increased weight gain rate by 12.67% and reduced feed conversion ratio of grass carp when compared to the GP(P<0.05),but its weight gain rate was still lower than the control group(P<0.05).When compared with the control,dried and germinated pea-based diets and sole germinated pea significantly reduced the steaming loss by 24.20%,25.46%,and 25.35%(P<0.05),increased hardness and chewiness(P<0.05),decreased muscle fiber diameter and increased density accordingly(P<0.05),and increased flesh collagen content by 21.13%,21.51%,and 23.0%(P<0.05),respectively.The relative expressions of COL1A1 and COL1A2 mRNA in muscle and skin were significantly higher in germinated pea and two pea-based groups than in the control group(P<0.05).There was no significant difference in muscle moisture,crude protein,crude lipid,and ash contents among all treatments(P>0.05).In conclusion,germinated pea-based diet promoted the growth of grass carp when compared to the sole germinated pea,and improved the flesh quality by increasing collagen content and collagen gene expression in muscle when compared to the formula diet.