寡果糖诱导瘤胃急性酸中毒对山羊瘤胃发酵、蹄组织结构及炎症因子、金属蛋白酶表达的影响

本试验旨在研究寡果糖诱导瘤胃酸中毒对山羊瘤胃发酵、蹄组织结构、蹄部炎症因子及金属蛋白酶表达的影响。采用随机区组设计,将8头健康装有永久性瘤胃瘘管的波杂山羊(波尔山羊×长江三角洲白山羊)随机分为对照组和诱导酸中毒的试验组,每组4头。其中试验组山羊瘤胃寡果糖灌注量为21 g/kg BW。分别于灌注前(0 h)和灌注后4、8、12、24和48 h采集瘤胃液,同时分别在0、4、8、24和48 h通过颈静脉采集血液,灌注后48 h屠宰2组山羊,采集蹄组织。结果表明:与对照组相比,试验组山羊瘤胃液p H、挥发性脂肪酸浓度平均值显著降低(P0.05),血液和瘤胃液中乳酸和脂多糖浓度平均值显著提高(P0.05);组织形态学结果显示,与对照组相比,试验组山羊蹄组织中次级表皮蹄小叶和次级真皮蹄小叶的长度变短,蹄小叶形状不规则;实时定量PCR检测结果显示,较对照组比较,试验组山羊蹄组织中基质金属蛋白酶组织抑制物-1的mRNA的相对表达量显著降低(P0.05),白细胞介素-6、膜型基质金属蛋白酶-1和基质金属蛋白酶-2的mRNA的相对表达量显著升高(P0.05)。结果提示,寡果糖诱导山羊急性瘤胃酸中毒可导致山羊瘤胃发酵紊乱,提高瘤胃液和血液中脂多糖与乳酸浓度,导致山羊蹄组织相关炎症因子与金属蛋白酶表达改变,最终引发山羊急性蹄叶炎。

Effects of Ruminal Acute Acidosis Induced by Fructo-Oligosaccharide on Ruminal Fermentation,Hooves Structure and Expressions of Inflammatory Cytokines and Matrix Metalloproteinase of Goats

The present study aimed to investigate the effects of ruminal acute acidosis induced by fructo?oligo?saccharide on ruminal fermentation, hooves structure and expressions of inflammatory cytokines and matrix metalloproteinase of goats. Eight healthy crossbred goats ( Boer goat × Yangtze River delta white goats) with permanent ruminal fistulas were randomly divided into two groups, including control and test groups which was treated with fructo?oligosaccharide infusion (21 g/kg BW), and each group had 4 goats. Ruminal liquid and blood were collected respectively at 0 ( before infusion) , 4, 8, 12, 24 and 48 h, as well as 0, 4, 8, 24 and 48 h after infusion. The goats were slaughtered to collect for hooves tissue after 48 h of infusion. The results showed as follows, compared with control group, the average values of ruminal liquid pH, volatile fatty acids was significantly decreased in test group (P<0.05), while the average values of the concentrations of lactic acid and lipopolysaccharide ( LPS) in ruminal liquid and blood were significantly increased ( P<0.05);the re?sults of histology suggested that compared with control group, secondary epidermal lamellae and secondary der?mal lamellae were shortened in test group; the real?time PCR results revealed that compared with control group, the mRNA expression of tissue inhibitors of metalloproteinases?1 ( TIMP?1) was significantly decreased in test group ( P<0.05) , while those of interleukin?6 ( IL?6) , matrix metalloproteinase 2 ( MMP?2) and mem?brane type?1 matrix metalloproteinases ( MT1?MMP) in goat hooves were significantly increased ( P<0.05) . In conclusion, ruminal acute acidosis induced by fructo?oligosaccharide causes the disorder of ruminal fermenta?tion and increases concentrations of LPS and lactic acid in ruminal liquid and blood, which further changes of mRNA expressions of pro?inflammatory cytokines and matrix metalloproteinase genes related to laminitis, and finally induces the laminitis in goats.