【摘要】 以初始体质量为(9.87±0.20)g的全雄奥尼罗非鱼(Oreochromis niloticus♀×O.aureus♂)为实验对象,研究饲料中不同水平谷氨酰胺对奥尼罗非鱼生长、饲料利用及抗病力的影响。实验共设6个处理组,每组谷氨酰胺添加量分别为饲料质量的0、0.2%、0.4%、0.6%、0.8%和2.0%,各设3个平行。用开放式流水养殖,饲养8周。之后注射嗜水气单胞菌(Aeromonas hydrophila)进行感染实验,观察7d,计算成活率。结果表明,饲料中添加谷氨酰胺对杂交罗非鱼的增重率、特异生长率、成活率及饲料系数均无显著影响(P>0.05),但对蛋白效率和蛋白质沉积率影响显著(P<0.05)。添加量为0.6%和0.8%组的蛋白质效率显著高于添加量为0～0.4%组(P<0.05),其余各组间差异不显著(P>0.05)。蛋白质沉积率则以添加0.8%组最高,显著高于添加量为0～0.4%组(P<0.05),其余各组间差异不显著(P>0.05)。谷氨酰胺对杂交罗非鱼的肥满度和脾体比有显著影响(P<0.05),但对肝体比和头肾体重比则影响不显著(P>0.05)。用嗜水气单胞菌分别攻毒48h、72h和96h,谷氨酰胺0.6%～0.8%饲料组罗非鱼的存活率影响显著高于0～0.4%组(P<0.05);而对攻毒后1h及24h的存活率各添加组间无显著影响(P>0.05)。综上结果,建议奥尼罗非鱼配合饲料中谷氨胺酰胺的适宜添加水平为0.6%～0.8%。更多还原

【Abstract】 This study was conducted to determine the effects of glutamine with different dietary supplementation levels(0,0.2%,0.4%,0.6%,0.8% and 2.0%)on growth performance,feed utilization,body composition and anti-disease ability of juvenile hybrid tilapia(Oreochromis niloticus ♀× O.aureus ♂)for 8 weeks.Six iso-nitrogenous and iso-energic diets were formulated as experimental diets.The results showed that the diet with glutamine supplementation significantly increase the protein efficiency ratio(PER)and productive protein value(PPV)(P<0.05),but could not significantly increase the weight gain rate(WG),specific growth rate(SGR),feed convention ratio(FCR) and survival rate of juvenile tilapia(P>0.05).The whole condition factor(CF)and spleen body index(SBI)were significantly affected by the dietary glutamine supplementation levels(P<0.05),while there was no signifi cant effect of glutamine supplementation levels on hepatopancrease body index(HBI)and head kidney body index(HKBI)(P>0.05).There were signifi cant differences(P<0.05)in moisture and protein content of whole body, but the variations were not marked(P>0.05)in lipid and ash contents of whole body.The challenge trial was done by intraperitoneal(i.p.)injection of Aeromonas hydrophila at a concentration of 0.2 mL/ind(LD50 around 107 CFU/mL).The control group(non-infective group)was injected i.p.with 0.2 mL at 0.9% NaCl per fi sh.The survival rates of 48 h,72 h and 96 h after challenge against A.hydrophila were signif icantly affected by the dietary glutamine supplementation levels(P<0.05), but survival rate at 1 h and 24 h were not affected(P>0.05).Based on PER,PPV and survival rate after challenge against A.hydrophila,the optimal dietary supplementation levels of glutamine for this diet formulation was 0.6%-0.8%.更多还原