Effects of Rapeseed Meal Replacing Fish Meal on Growth,Antioxidant Capacity and Intestinal Health of Black Carp(Mylopharyngodon piceus)
This experiment aimed to investigate the effects of rapeseed meal replacing fish meal on the growth,antioxidant capacity and intestinal health of black carp(Mylopharyngodon piceus).Six isonitrogen and isolipid diets were designed and prepared by replacing 0(control group),10％(10％group),20％(20％group),30％(30％group),40％(40％group)and 50％(50％group)of fish meal with rapeseed meal based on a basal diet,respectively.The black carp with an initial body weight of(6.73±0.70)g were fed the experimen-tal diets for 8 weeks.Each experimental diet was fed to 4 breeding buckets with 35 fish per bucket.The results showed as follows:1)there were no significant differences in weight gain rate(WGR)and specific growth rate(SGR)among the control group,10％group and 20％group(P＞0.05),while the WGR and SGR in the 30％group,40％group and 50％group were significantly lower than those in the control group and 10％group(P＜0.05).With the rapeseed meal replacement level increasing,the condition factor(CF),hepa-tosmatic index(HSI)and intestinosomatic index(ISI)were decreased,and the feed conversion ratio(FCR)firstly decreased and then increased.The FCR in the 50％group was significantly higher than that in the control group and 10％group(P＜0.05).2)There were no significant differences in the moisture and ash content of whole fish among groups(P＞0.05);the crude protein and crude lipid contents of 30％group,40％group and 50％group were decreased with the rapeseed meal replacement level increasing,and those in the 40％group and 50％group were significantly lower than those in the control group(P＜0.05).There were no significant differences in moisture,ash and crude lipid of muscle among groups(P＞0.05),while the crude protein con-tent of muscle in the 30％group,40％group and 50％group was significantly decreased compared with the control group(P＜0.05).3)There were no significant differences in the apparent digestibility coefficients of dry matter and crude lipid among groups(P＞0.05).The apparent digestibility coefficient of crude protein in the 30％group,40％group and 50％group was significantly lower than that in the control group(P＜0.05).When the fish meal replaced by rapeseed meal exceeded 10％,the activities of intestinal trypsin,lipase and amylase in intestine were significantly decreased compared with control group(P＜0.05).4)The total antioxi-dant capacity(T-AOC)and superoxide dismutase(SOD)activity in serum showed a decreasing trend among the experimental groups,but there were no significant differences among groups(P＞0.05).When the fish meal replaced by rapeseed meal exceeded 20％,serum catalase(CAT)activity was significantly decreased(P＜0.05),and serum malondialdehyde(MDA)content was significantly increased(P＜0.05).5)The intes-tinal villi length,villi width and muscle thickness decreased significantly when the fish meal replaced by rape-seed meal exceeded 10％(P＜0.05).At phylum level,the dominant microbial phyla in intestinal flora of black carp were Proteobacteria,Bacteroidetes and Actinobacteria.At genus level,the dominant microbial genera in intestinal flora of black carp were Chrysobacillus,Achromobacillus and Aeromonas.The relative abundances of Proteobacteria and Aeromonas were when 20％and 50％fish meal replaced by rapeseed meal.In summary,an appropriate proportion of rapeseed meal instead of fish meal in the diet of black carp should not exceed 20％,which will not have noticeable adverse effects on the growth and antioxidant capacity of black carp.[Chinese Journal of Animal Nutrition,2024,36(6):3876-3891]
black carprapeseed mealfish mealgrowthanti-oxidationintestinal health
万方数据
维普
