高精料日粮对奶山羊肝、脾炎性因子表达的影响

doi:10.11843/j.issn.0366-6964.2020.07.017

摘要/Abstract

摘要： 为探究饲喂高精料日粮对泌乳奶山羊肝、脾组织的影响及机制，将14只泌乳初期关中奶山羊随机分为对照组（6只）和试验组（8只），对照组饲喂普通（精粗比35：65）日粮，试验组饲喂高精料（精粗比65：35）日粮，试验期19周。于试验的0、1、4、8、12、15、16、18、19周每周采集所有羊乳汁测定乳脂率，6~18周每周日采集所有羊粪便测定pH，试验结束当日采集肝、脾组织，制作组织切片观察肝、脾组织形态变化；采用RT-qPCR检测肝、脾组织中炎性因子及TLR4通路关键蛋白的基因表达；采用Western blot技术检测TLR4通路关键蛋白的表达水平。结果显示，长期饲喂高精料日粮造成奶山羊乳脂率降低，试验的16、18和19周与对照组差异显著（P<0.05）；试验组奶山羊粪便pH均值从第9周开始下降，13~18周与对照组差异显著（P<0.05）；试验组奶山羊肝细胞颗粒变性或空泡变性，肝小叶中央静脉周围有炎性细胞浸润，脾组织无明显变化；肝组织中促炎因子IL-6和TNF-β以及TLR4与NF-κB2基因表达显著升高（P<0.05）；脾组织中促炎因子TNF-β和抗炎因子IL-10以及TLR4基因表达显著升高，NF-κB2基因表达显著降低（P<0.05）；肝组织中与TLR4通路相关的p38、JNK、ERK和p65这4种蛋白的表达变化不明显，脾组织p38、ERK和p65表达与对照组相比虽差异不显著，但都呈现下降趋势。综上所述，长期饲喂高精料日粮导致奶山羊乳脂率和粪便pH降低，通过上调NF-κB的基因表达诱导肝组织中IL-6和TNF-β基因表达升高，从而对肝造成炎性损伤，对脾组织影响不明显。

关键词: 奶山羊, 高精料日粮, 肝和脾, 炎性因子

Abstract: To explore the effects and mechanism of high concentrate diet on hepatic and spleen tissues in dairy goats, 14 Guanzhong dairy goats at the early stage of lactation were randomly divided into control group (CG, n=6) and experimental group (EG, n=8). The CG was fed with a normal diet (concentrate:roughage=35:65), and the EG was fed with a high concentrate diet (concentrate:roughage=65:35). The trial lasted for 19 weeks. The milk from all goats was collected at 0, 1, 4, 8, 12, 15, 16, 18 and 19 weeks to analyze milk fat. Every Sunday from 6 to 18 weeks, all sheep feces were collected for pH determination. After autopsy at the end of the experiment, hepatic and spleen tissues were collected and tissue sections were made to observe the morphological changes of the hepatic and spleen tissues. The gene expression of inflammatory cytokines and key proteins of the TLR4 pathway in hepatic and spleen tissues were detected with the RT-qPCR method. The expression level of key proteins in the TLR4 pathway was analyzed using the Western blot method. The results showed that milk fat of EG decreased and was significantly different from those of CG at 16, 18 and 19 weeks (P<0.05). Average fecal pH of EG declined from the 9th week, and the difference was significant between EG and CG from 13 to 18 weeks (P<0.05). Hepatocyte was granule or vacuole degeneration and there was inflammatory cell infiltration around central vein of hepatic lobular. The spleen tissues' change was not obvious. The expression of pro-inflammatory factors IL-6 and TNF-β, as well as TLR4 and NF-κB2 genes were significantly increased in hepatic tissues (P<0.05). The expression of TNF-β, IL-10 and TLR4 genes were significantly increased, while the expression of NF-κB2 was significantly decreased in spleen tissues (P<0.05). p38, JNK, ERK and p65 proteins' expressions in hepatic tissues were not significantly changed, while the expressions of p38, ERK and p65 proteins in spleen tissues showed decreased trend. Those indicated that the decline of milk fat and fecal pH were induced by long-term feeding high-concentration diet. Upregulating of NF-κB gene expression led to the increased expression of IL-6 and TNF-β genes in the hepatic tissues of dairy goats, which caused inflammatory damage to the hepatic tissues, but had no obvious effect on the spleen tissues.

Key words: dairy goat, high concentrate diet, hepar and spleen, inflammatory cytokine

中图分类号:

S852.2

胡永林, 张祥胤, 毋程飞, 李贤, 穆杨, 丛日华. 高精料日粮对奶山羊肝、脾炎性因子表达的影响[J]. 畜牧兽医学报, 2020, 51(7): 1646-1655.

HU Yonglin, ZHANG Xiangyin, WU Chengfei, LI Xian, MU Yang, CONG Rihua. Effects of High Concentrate Diet on Expression of Inflammatory Factors of Liver and Spleen in Dairy Goats[J]. Acta Veterinaria et Zootechnica Sinica, 2020, 51(7): 1646-1655.

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