蜡样芽孢杆菌对银鲑生长性能、血清生理生化指标、肝脏抗氧化能力及肠道的组织结构影响

Effects of Dietary Bacillus cereus on Growth Performance,Serum Physiology and Biochemical Indices,Liver Antioxidant Capacity and Intestinal Histological Structure of Coho Salmon(Oncorhynchus kisutch)

在水温10~18℃下,将初始体质量(130.2±10.5)g的银鲑(Oncorhynchus kisutch)饲养在流水水泥池中1×1×0.8(m^(3))的网箱中,每箱20尾,投喂喷淋活蜡样芽孢杆菌(Bacillus cereus)菌液的饲料,添加量分别为0 CFU/g(CK对照组)、8×10^(11)CFU/g(H组)、4×10^(9)CFU/g(M组)和2×10^(7)CFU/g(L组)6周,每组设3个重复,研究饲料中添加不同浓度的蜡样芽孢杆菌对银鲑生长性能、血清生理生化指标、肝脏抗氧化能力以及肠道组织结构的影响。结果表明,投喂添加蜡样芽孢杆菌饲料的银鲑增重率(WGR)、肝体比(HSI)、存活率(SR)和特定生长率(SGR)均显著高于对照组(P<0.05),饲料系数(FCR)显著降低(P<0.05),蛋白质效率(PER)显著提高(P<0.05);各试验组银鲑血清中总胆固醇(T-CHO)、血清葡萄糖(GLU)、血清总蛋白(TP)含量与血清白蛋白(ALB)含量均显著提高(P<0.05)。其中,蜡样芽孢杆菌M组CHO、GLU、TP与ALB含量较其余实验组显著提高(P<0.05);各实验组银鲑血清谷丙转氨酶(GPT)与谷草转氨酶(GOT)活性与对照组无显著差异(P>0.05)。各实验组血清碱性磷酸酶(AKP)与空白对照差异显著(P<0.05);各试验组银鲑肝脏超氧化物歧化酶(SOD)、过氧化氢酶(CAT)以及谷胱甘肽过氧化物酶(GSH-PX)酶活性较对照组显著提高(P<0.05),H组和M组丙二醛(MDA)较对照组显著降低(P<0.05),L组MDA与对照组降低但差异不显著(P>0.05),各实验组还原性谷胱甘肽(GSH)较对照组显著增高(P<0.05),H组和M组总抗氧化能力(T-AOC)较对照组显著增高(P<0.05),L组与对照组并无显著差异(P>0.05)。各实验组肠道肌层高度、绒毛长度、隐窝厚度较对照组均有提高,其中M组后肠各指标显著提高(P<0.05)。综上所述,饲料中添加4×109CFU/g蜡样芽孢杆菌可以促进银鲑的生长,改善血清生化指标,提高肝脏抗氧化能力,改善肠道健康。

Coho salmon(Oncorhynchus kisutch)with an initial body weight of(130.2±10.5)g were housed in 1×1×0.8(m^(3))cages in a flowing cement pond at stocking density of 20 individual per cage,and fed the diets sprayed with Bacillus cereus solution at a dose of 0 CFU/g(CK control group),8×1011 CFU/g(H group),4×10^(9) CFU/g(M group)or 2×10^(7) CFU/g(L group)at water temperature of 10-18℃with three replicates in each group for 6 weeks to evaluate the effects of B.cereus supplementation with different concentrations on the growth performance,serum physiological and biochemical indices,liver antioxidant capacity and intestinal histological structure of coho salmon.The results showed that the coho salmon fed the diets containing B.cereus had significantly higher weight gain rate (WGR), hepatosomatic ratio (HSI), survival rate (SR) and specific growth rate (SGR) than those in the control group did (P < 0.05), with significant decrease in feed conversion ratio (FCR) (P < 0.05). There were significantly increase in protein efficiency (PER) and contents of serum total cholesterol (T-CHO), serum glucose (GLU), serum total protein (TP) and serum albumin (ALB) in the treatment groups(P < 0.05). The contents of CHO, GLU, TP and ALB were shown to be significantly higher in M group than those in other groups (P < 0.05), without significant differences in activities of serum glutamic-pyruvate transaminase (GPT) and glutamic-oxalacetic transaminase(GOT) between the treatment groups and the control group(P > 0.05), and significant differences in serum alkaline phosphatase(AKP) between the treatment groups and the control group (P < 0.05). The activities of superoxide dismutase(SOD), catalase(CAT) and glutathione peroxidase(GSH-Px) in liver were significantly increased in the treatment groups compared with the control group(P < 0.05) and the malondialdehyde(MDA) content in H and M groups was significantly decreased compared with the control group(P < 0.05). Compared with the control group, MDA content in the L group was decreased, without significant difference(P > 0.05), reduced glutathione(GSH) was significantly increased in all treatment groups compared with the control group (P < 0.05). Total antioxidant capacity (T-AOC) in H and M was significantly increased compared with the control group (P < 0.05), without difference between L and the control groups(P > 0.05). Compared with the control group, the muscular height, villus length and crypt thickness of intestinal mucosa in all treatment groups were increased, and the indices of posterior intestine were significantly increased in M group(P < 0.05). In conclusion, dietary supplementation with 4×10^(9) CFU/g B. cereus can promote the growth of coho salmon, and improve the serum biochemical indices, the antioxidant capacity of liver, and intestinal health of coho salmon.