投喂频率对珍珠龙胆石斑鱼生长性能、免疫、血清及肝脏生化指标的影响

Effects of Feeding Frequency on Growth Performance,Immune,Serum and Hepatic Biochemical Indexes in Grouper(Epinephelus fuscoguttatus♀×E.lanceolatu)

本试验旨在研究投喂频率对珍珠龙胆石斑鱼(Epinephelus fuscoguttatus♀×E.lanceolatu)生长性能、免疫、血清及肝脏生化指标的影响。在摄食高脂饲料的条件下,采用4种投喂频率(1、2、3、4次/d)投喂初始质量为(11.51±0.02)g的石斑鱼56 d,共360尾,每种投喂频率设3个重复,每个重复1个0.3 m 3玻璃钢桶,每桶30尾鱼。结果表明:1)1次/d组石斑鱼终末体质量(FBM)、增重率(WGR)及特定生长率(SGR)显著低于其他各组(P<0.05),其他各组间无显著差异(P>0.05)。2次/d组饲料系数(FCR)最低,显著低于1次/d组(P<0.05)。投喂频率对石斑鱼脏体比(VSI)、肝体比(HSI)与肥满度(CF)无显著影响(P>0.05)。2)1次/d组血清甘油三酯(TG)含量显著低于其他各组(P<0.05)。各组间血清总胆固醇(TC)含量无显著差异(P>0.05)。随着投喂频率的升高,血清低密度脂蛋白(LDL)含量呈逐渐降低趋势,在1次/d组有最大值,显著高于其他各组(P<0.05),血清高密度脂蛋白(HDL)含量则呈相反趋势,在1次/d组有最小值,显著低于其他各组(P<0.05),血清过氧化氢酶(CAT)与超氧化物歧化酶(SOD)活性呈上升的趋势,在4次/d组有最大值,显著高于其他各组(P<0.05)。血清总抗氧化能力(T-AOC)呈先上升后稳定的趋势,3、4次/d组显著高于1、2次/d组(P<0.05)。3)1次/d组肝脏T-AOC,CAT、SOD、溶菌酶(LYS)活性及免疫球蛋白(IgM)含量显著低于其他各组(P<0.05)。4)4次/d组肝脏TG含量显著高于其他各组(P<0.05)。1次/d组肝脏TC含量显著高于其他各组(P<0.05)。4次/d组肝脏极低密度脂蛋白(VLDL)含量显著低于其他各组(P<0.05)。4次/d组肝脏脂蛋白脂酶(LPL)活性显著高于其他各组(P<0.05),肝脏肝脂酶(HL)活性呈现上升趋势,3、4次/d组显著高于1、2次/d组(P<0.05)。3次/d组肝脏甘油三脂酶(ATGL)活性显著高于其他各组(P<0.05)。综上所述,适宜的投喂频率能提高石斑鱼的生长性能、抗氧化能力和脂代谢能力。本试验条件下,摄食高脂饲料石斑鱼的最佳投喂频率为2次/d。

This experiment was conducted to investigate the effects of feeding frequency on growth performance,immune,serum and hepatic biochemical indexes in grouper(Epipehelus fuscoguttatus♀×E.lanceolatu).Under the conditions of feeding a high-lipid diet,a total of 360 groupers with an initial body weight of(11.51±0.02)g were fed at 4 feeding frequencies(1,2,3,4 times/d)for 56 days,with 3 replicates per feeding frequency and one 0.3 m 3 fiberglass barrel per replicate,with 30 fish per barrel.The results showed as follows:1)the final body mass(FBM),weight gain rate(WGR),and specific growth rate(SGR)of the 1 time/d group were significantly lower than those of the other groups(P<0.05),with no significant differences among the other groups(P>0.05).The 2 time/d group had the lowest feed conversion ratio(FCR),significantly lower than the 1 time/d group(P<0.05).Feeding frequency did not affect the visceral somatic index(VSI),hepatosomatic index(HSI),and condition factor(CF)of the groupers(P>0.05).2)The serum triglyceride(TG)content of the 1 time/d group was significantly lower than that of the other groups(P<0.05).There were no significant differences in serum total cholesterol(TC)content among the groups(P>0.05).As feeding frequency increased,the serum low-density lipoprotein(LDL)content showed a gradually decreasing trend,with the highest value observed in the 1 time/d group,which was significantly greater than that of the other groups(P<0.05).In contrast,the serum high-density lipoprotein(HDL)content exhibited an opposite trend,with the lowest value found in the 1 time/d group,which was significantly less than that of the other groups(P<0.05).The activities of catalase(CAT)and superoxide dismutase(SOD)increased,with the highest values in the 4 time/d group,significantly higher than that of the other groups(P<0.05).The total antioxidant capacity(T-AOC)showed an increasing and then stable trend,with the 3 and 4 time/d groups were significantly higher than the 1 and 2 time/d groups(P<0.05).3)The liver T-AOC and CAT,SOD,lysozyme(LYS)activities,and immunoglobulin M(IgM)content of the 1 time/d group were significantly lower than those of the other groups(P<0.05).4)The liver TG content of the 4 time/d group was significantly higher than that of the other groups(P<0.05).The liver TC content of the 1 time/d group was significantly higher than that of the other groups(P<0.05).The very-low-density lipoprotein(VLDL)content of the 4 time/d group was significantly lower than that of the other groups(P<0.05).The liver lipoprotein lipase(LPL)activity of the 4 time/d group was significantly higher than that of the other groups(P<0.05),and the hepatic lipase(HL)activity showed an increasing trend,with the 3 and 4 time/d groups significantly higher than the 1 and 2 time/d groups(P<0.05).The very low density lipoprotein(ATGL)activity of the 3 time/d group was significantly higher than that of the other groups(P<0.05).In summary,an appropriate feeding frequency enhances the growth performance,antioxidant capacity,and lipid metabolism in groupers.Under the conditions of this experiment,the optimal feeding frequency for groupers fed with a high-lipid diet is 2 time/d.