酵母产品对凡纳滨对虾的诱食效果及生长性能的影响

Effects of the yeast products on feed attractants and growth performance of Litopenaeus vannamei

试验通过比较凡纳滨对虾对3种酵母产品(鲜酵母粉、酵母核苷酸、啤酒酵母水解物)的诱食效果,研究诱食效果最佳的产品在高低蛋白水平下对凡纳滨对虾生长性能的影响。将基础饲料中3%秘鲁鱼粉等量替换为鲜酵母粉、酵母核苷酸、啤酒酵母水解物,添加氧化钇(Y2O3)、氧化钕(Nd2O3)、氧化镧(La2O3)和氧化镱(Yb2O3)作为惰性标物,用于测定选食偏好。试验设4个重复,将4种饲料等量混合投喂,并收集粪便,分析粪便中惰性元素的比例。研究发现,对虾对不同饲料的选食偏好高低为酵母核苷酸组>鲜酵母粉组>鱼粉组>啤酒酵母水解物组,且各组间差异显著(P<0.05)。为探讨酵母核苷酸在不同蛋白水平下对凡纳滨对虾的生长的影响,试验采用2×2双因素设计2个蛋白水平(36%、45.27%)和2个酵母核苷酸水平(0、0.8%),形成4种试验饲料。选取480尾初始体质量(0.79±0.01)g对虾幼虾,随机分成4组,每组4个重复,试验周期56 d。试验结果显示,低蛋白水平能显著提高对虾存活率、终末体均质量、增重率、特定生长率、摄食量和蛋白质保留率(P<0.05);饲料中添加酵母核苷酸均能显著提高对虾存活率(P<0.05),提高终末体均质量、增重率和特定生长率(P>0.05),降低饲料系数(P>0.05)。各组间的干物质、粗蛋白质、粗脂肪和灰分含量不显著(P>0.05)。综上所述,在本试验条件下,酵母核苷酸具有较好的诱食效果,饲料添加0.8%酵母核苷酸能促进摄食,提高生长性能,在低蛋白水平下作用更显著。

This experiment was compared the attractive effects ofLitopenaeus vannamei on three yeast products(fresh yeast powder,yeast nucleotide and hydrolyzate of beer yeast),and studied the best at⁃tractive effects of yeast products of protein levels on growth ofLitopenaeus vannamei.Three experimen⁃tal diets were formulated with fresh yeast powder,yeast nucleotide or hydrolyzate of beer yeast re⁃placed 3%fish meal in basal diet,respectively.Each diet mixed with one kind of inert element(Y2O3,La2O3,Nd2O3,Yb2O3).Shrimps were fed mixed diet with equal amount of four marked diets.Preference for each diet was estimated by the relative concentration of single inert element.The results showed that there were significantly different about the preference of the four kinds of diets fed shrimps,yeast nucleotides>fresh yeast powder>fish meal>hydrolyzate of beer yeast(P<0.05).A random 2×2 two-factors animal experiment including two different protein levels(36%,45.27%)and two yeast nucleotides levels(0,0.8%)was used to formulate 4 trial diets.Each treatment had 4 rep⁃licates and 480 shrimps with an average body weight(0.79±0.01)g individuals per replicate.The experiment lasted for 56 d.The results showed that low protein level of diet significantly improved the survival rate(SR),average terminal weight,weight gain rate(WGR),specific growth rate(SGR),food intake(FI)and protein deposition rate(PDR)of shrimps(P<0.05).The diet with yeast nucleotide significantly increased SR of shrimps(P<0.05),increased the average terminal weight,WGR,SGR(P>0.05),reduced feed coefficient(P>0.05).There were no significantly influences on dry matter,crude protein,crude lipid and ash contents of whole shrimps(P>0.05).In conclusion,the attractive effects of yeast nucleotide onLitopenaeus vanna⁃mei was the best.The diet added 0.8%yeast nucleotides could promote food ntake and improved the growth performance,especially in low protein level.