饲料中不同含量豆粕对乌苏里拟鲿生长、体成分及表观消化率的影响
EFFECTS OF REPLACING FISH MEAL WITH SOYBEAN MEAL ON GROWTH PERFORMANCE, BODY COMPOSITION AND APPARENT DIGESTIBILITY COEFFICIENTS OF PSEUDOBAGRUS USSURIENSIS
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摘要: 以初始体重(0.500.00) g的乌苏里拟鲿(Pseudobagrus ussuriensis)稚鱼为试验对象, 在室内进行为期8周的摄食生长实验, 研究饲料中豆粕替代鱼粉蛋白对乌苏里拟鲿生长、体成分及消化率的影响。以豆粕分别替代对照饲料(S0)中10%(S10)、20%(S20)、30%(S30)、40%(S40)、50%(S50)和60%(S60)的鱼粉蛋白, 另外,60%组添加0.3%蛋氨酸(SM60), 共配制8种等氮等能试验饲料。结果表明, 随着饲料中豆粕替代比例的增大,试验鱼的增重率、特定生长率和蛋白质效率均逐渐降低, 但10%40%替代组与对照组之间差异不显著(P0.05), S50和S60显著低于对照组(P0.05); 与S60组相比, SM60组增重率和特定生长率有所提高(P0.05),但显著低于0%40%替代组(P0.05); 饲料系数的变化规律与增重率的趋势正好相反; 当饲料中豆粕替代水平由0%增加到20%时, 乌苏里拟鲿的摄食率由3.22%提高到3.55%, 而后随着替代比例进一步增加, 摄食率逐渐降低, 但方差分析表明, 差异不显著。饲料中豆粕替代鱼粉对乌苏里拟鲿全鱼水分和灰分含量的影响不显著, 肌肉水分随着替代比例的升高而逐渐升高; 全鱼和肌肉粗蛋白含量随着替代比例的升高而逐渐降低, 其中, S60和SM60组显著低于其他组(P0.05); 随着替代比例的升高, 全鱼和肌肉粗脂肪呈现升高的趋势, S60和SM60组显著高于其他替代组(P0.05); 肥满度在各组间差异不显著(P0.05); 当豆粕替代鱼粉蛋白比例为60%时, 肝体比、脏体比指数显著高于其他组(P0.05), 而其他组间差异不显著(P0.05)。50%和60%替代组的蛋白质和干物质的表观消化率显著低于040%替代组(P0.05), 而040%替代组之间差异不显著(P0.05);随着豆粕替代比例由0升高到60%, 磷表观消化率由36.07% 升高到66.50%。在实验条件下, 豆粕替代乌苏里拟鲿饲料中40%鱼粉蛋白, 不会影响乌苏里拟鲿的生长和饲料利用, 而高比例替代对生长和鱼的健康有负面影响。Abstract: An 8-week feeding trial was conducted in indoor culture system to evaluate effects of replacing fish meal with soybean meal (SBM) on growth performance, body composition and apparent digestibility coefficients of juvenile Pseudobagrus ussuriensis initial body weight of (0.500.00) g. Seven isonitrogenous diets groups were formulated to replace fish meal protein by SBM at 0 (S0), 10% (S10), 20% (S20), 30% (S30), 40% (S40), 50% (S50) and 60% (S60). To investigate the effect of supplementation with methionine, S60 added 0.3% methionine to formulated the 8th group (SM60). Weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) linearly decreased with increasing SBM replacement level from 0 to 60%. There were no significant differences in WGR, SGR and PER among groups of S0, S10, S20, S30, and S40 (P0.05), but S50 and S60 groups had lower WGR, SGR and PER than S0 group (P0.05). No significant differences were observed in growth between S60 group and SM60 (P0.05) group, but both of them had significantly lower growth than S0 group. Feed conversion ratio (FCR) had an opposite trend with WGR and SGR. S0 group had significantly lower muscle moisture content than other groups (P0.05). Whole body and muscle protein contents decreased with increasing dietary SBM levels, and S60 and SM60 groups had significantly lower protein content than other groups (P0.05). Whole body and muscle lipid contents increased with increasing dietary SBM levels, and S60 and SM60 groups had significantly higher lipid contents than other groups (P0.05). S60 and SM60 groups had higher VSI and HSI than other groups (P0.05). Apparent digestibility coefficients (ADC) of protein and dry matter of S50 and S60 groups were significantly lower than other groups (P0.05). The ADC of phosphorus significantly increased with increasing SBM levels in the diet (P0.05). These results suggest that SBM at not more than 40% of fish meal protein replacement have no significantly negative effect on growth or feed efficiency, but higher dietary SBM levels reduce fish performance.