日粮添加壳聚糖对鹅生长性能、血脂及脂代谢相关基因表达的影响

摘要

The objective of this study was to investigate the effect of dietary chitosan (CTS) levels on the growth performance and mechanism of dietary CTS levels on the hepatic lipid metabolism of geese.Three hundred and sixty 14-day-old healthy Yangzhou male geese were randomly divided into five groups with 6 replicates per group and 12 geese each.Geese were respectively fed with basal diet (control group),normal diet + 250 mg/kg CTS diet (group Ⅰ),normal diet + 500 mg/kg CTS diet (group Ⅱ),normal diet + 1 000 mg/kg CTS diet (group Ⅲ) and normal diet + 2 000mg/kg CTS diet (group Ⅳ) for fifty and six days,respectively.The results showed that:1) Supplement of 250-500mg/kg CTS significantly increased ADFI and ADG and 70-day-old body weight (P＜0.05);2) Compared with the control group,serum TC and LDL concentrations significantly decreased with supplement of CTS within 250-1 000 mg/kg range (P＜0.05).Serum TG and HDL-C concentration had no significant difference among five groups;3) Supplement of 250-500 mg/kg CTS reduced ACC activity and the mRNA expression of ACC and FAS.The expression of PPAR-α was up-regulated with the increasing of CTS dose;4) The CTS dose had no significant effect on FAS and LPL activity in the liver (P＞0.05).The HL activities of 500 and 1 000 mg/kg CTS groups were significantly decreased.In conclusion,supplemental CTS increased ADFI and ADG,decreased serum TC and LDL levels,affected liver lipid metabolism enzyme activity and related genes expression.The optimal dietary of 250-500 mg/kg chitosan in diet was recommended.%为研究日粮中添加不同剂量的壳聚糖对内仔鹅生长性能、血脂成分、肝脏脂代谢关键酶及其mRNA表达的影响,探讨壳聚糖调控鹅脂质代谢的机理.选取14日龄扬州鹅公仔鹅360只,随机分为5组各6个重复,每个重复12只.即基础饲粮组(对照组,C),基础饲粮+250 mg/kg(Ⅰ),基础饲粮+500 mg/kg(Ⅱ)、基础饲粮+1 000 mg/kg(Ⅲ)及基础饲粮+2 000 mg/kg(Ⅳ)壳聚糖组,试验期56 d.结果表明:1)饲粮中添加250和500mg/kg的壳聚糖均能显著提高试验鹅日采食量(ADFI)、日增重(ADG)及70日龄体重(P＜0.05);2)在250～1 000 mg/kg范围内,和对照组相比,试验组血清总胆固醇(TC)及低密度脂蛋白(LDL)浓度显著降低(P＜0.05);不同处理组间血清甘油三酯(TG)、高密度脂蛋白(HDL)差异不显著(P＞0.05);3)饲粮中添加250和500 mg/kg的壳聚糖能够显著降低肝脏乙酰辅酶A羧化酶(ACC)活性,并抑制ACC和脂肪酸合成酶(FAS) mRNA的表达(P＜0.05).试验鹅肝脏过氧化物酶体增殖物激活受体α(PPAR-α) mRNA表达水平随着壳聚糖水平提高,显著上调;4)在250～2 000 mg/kg范围内,壳聚糖添加量不影响试验鹅肝脏FAS及LPL活性(P＞0.05).但500和1 000 mg/kg壳聚糖能显著降低其肝脏HL活性.综上所述,壳聚糖能够通过影响肝脏脂肪代谢酶活性及脂代谢相关基因的表达,调控试验鹅血脂代谢,提高其生长性能,添加量以250～500 mg/kg效果最佳.