摘要
本文旨在探讨不同精粗比饲粮中添加异位酸对体外瘤胃发酵的影响。选用4只体况良好、平均体重(25.48±1.51)kg、装有永久性瘤胃瘘管的阉割南江黄羊作为瘤胃液供体动物。用体外发酵法考察在3个精粗比(30∶70、50∶50和70∶30)饲粮中添加异位酸(1%)后的体外发酵参数变化。结果表明:经过24 h体外培养,不添加异位酸时,随精粗比由30∶70升高到70∶30,培养液pH、氨态氮(NH3-N)浓度、乙酸/丙酸和乙酸占总挥发性脂肪酸(TVFA)的比例均显著下降(P<0.05);产气量及乙酸、丙酸和TVFA浓度和丙酸占TVFA的比例均显著提高(P<0.05)。当精粗比为30∶70时,添加异位酸pH无明显变化,NH3-N浓度下降,产气量及微生物蛋白质(MCP)和丁酸浓度上升,但各项指标差异均不显著(P>0.05),而乙酸、丙酸和TVFA浓度均显著提高(P<0.05)。当精粗比为50∶50时,添加异位酸可显著降低NH3-N浓度(P<0.05),提高产气量及MCP、乙酸、丙酸和TVFA浓度(P<0.05),而对pH、丁酸浓度和乙酸/丙酸无显著影响(P>0.05)。当精粗比为70∶30时,添加异位酸NH3-N浓度显著下降(P<0.05),产气量及MCP、乙酸、丙酸和TVFA浓度显著上升(P<0.05),而对pH和乙酸/丙酸均无显著影响(P>0.05)。饲粮中添加异位酸有利于提高有机物的消化率和NH3-N的利用,增加M CP、乙酸、丙酸和TVFA的合成。在本试验中,对于MCP和TVFA的合成而言,精料比例越高,添加异位酸的效果越好。
This study was conducted to examine the effects of different forage to concentrate ratios and isoacids supplementation on rumen fermentation in vitro.The rumen fluid was collected from four castrated Nanjiang brown goats [(25.48±1.51) kg] fitted with permanent rumen fistulas.The trial was carried out using fermentation in vitro with the combinations of three forage to concentrate ratios(30∶ 50,50∶ 50 and 70∶ 30) and two isoacids concentrations(0 and 1%) in a two factorial arrangement.The results showed that after 24-hour fermentation in vitro,without isoacids supplementation,with the ratio of concentrate increased,the ruminal pH,NH3-N concentration,the ratio of acetate to propionate and the ratio of acetate to total volatile fatty acid(TVFA) were significantly decreased(P<0.05),but gas production,concentrations of acetate,propionate,TVFA,and the ratio of propionate to TVFA were increased significantly(P<0.05).When isoacids were added in 30∶ 70 group,there was a significant rise in concentrations of acetate,propionate and TVFA(P<0.05),but no significant influence on pH,gas production,concentrations of NH3-N,microbial protein(MCP),butyrate(P>0.05).When isoacids were added in 50∶ 50 group,the NH3-N concentration was significantly dropped(P<0.05),however,gas production,concentrations of MCP,acetate,propionate and TVFA were increased significantly(P<0.05),there were no significant effects on pH,butyrate concentration and the ratio of acetate to propionate(P>0.05).When isoacids were added in 70∶ 30 group,the NH3-N concentration was significantly decreased(P<0.05),there was a significant increase in gas production,concentrations of MCP,acetate,propionate and TVFA(P<0.05),and no significant influence on pH and the ratio of acetate to propionate(P>0.05).In conclusion,isoacids can increase the digestibility of organic matter and the utilization of NH3-N and enhance the synthesis of MCP,acetate,propionate and TVFA,and in this experiment,with the ratio of concentrate increased,the effects of isoacids supplementa
出处
《动物营养学报》
CAS
CSCD
北大核心
2012年第6期1181-1188,共8页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
四川省教育厅重点项目(07ZA071)
关键词
异位酸
精粗比
瘤胃发酵
体外培养
南江黄羊
isoacids
forage to concentrate ratio
rumen fermentation
in vitro
Nanjiang brown goat
