不同添加水平的肉桂醛对肉羊饲粮营养物质瘤胃降解特性及体外瘤胃发酵参数的影响

Effects of Different Supplemental Levels of Cinnamaldehyde on Ruminal Degradation Characteristics of Dietary Nutrients and Rumen Fermentation Parameters in Vitro for Meat Sheep

本试验旨在研究不同添加水平肉桂醛(CA)对肉羊饲粮营养物质瘤胃降解特性及体外发酵参数的影响。选取12只装有永久性瘤胃瘘管的杜×寒杂交成年肉用绵羊,随机分为4组,每组3只。在每千克基础饲粮中分别添加0(对照组)、200(200CA组)、300(300CA组)、400 mg(400CA组)的CA,采用尼龙袋法测定饲粮营养物质瘤胃降解率,采用体外产气法测定体外瘤胃发酵参数。结果显示:1)与对照组相比,200CA、300CA、400CA组的干物质(DM)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)的瘤胃有效降解率显著升高(P<0.05)。200CA、300CA组粗蛋白质(CP)的瘤胃有效降解率显著高于对照组(P<0.05),400CA组CP的瘤胃有效降解率显著低于对照组(P<0.05)。2)各组之间总产气量(72 h产气量)、pH及微生物蛋白(MCP)浓度均无显著差异(P>0.05)。与对照组相比,200CA、300CA、400CA组的甲烷(CH_(4))及氨态氮(NH_(3)-N)浓度显著降低(P<0.05)。3)各组之间总挥发性脂肪酸浓度以及丁酸、异丁酸、戊酸、异戊酸比例无显著差异(P>0.05),300CA组的丙酸比例显著高于对照组(P<0.05)。综上所述,CA可以调控肉羊的瘤胃发酵,提高饲粮中DM、NDF、ADF的瘤胃有效降解率以及饲粮氮在瘤胃中的存留率,降低CH 4产量。在本试验条件下,每千克饲粮中添加300 mg CA时效果最好。

This experiment was conducted to investigate the effects of different supplemental levels of cinnamaldehyde(CA)on rumen degradation characteristics of dietary nutrients and rumen fermentation parameters in vitro for sheep.Twelve adult Dorper×Han hybrid wethers sheep with permanent ruminal fistula were randomly divided into four groups with 3 sheep per group.CA with the supplemental levels of 0(control group),200(200CA group),300(300CA group)and 400 mg/kg(400CA group)were added into a basal diet,respectively.Nylon-bag method was used to determine the rumen degradation rates of dietary nutrients,and in vitro gas production method was used to determine the in vitro rumen fermentation parameters.The results showed as follows:1)compared with the control group,the rumen effective degradation rates of dry matter(DM),neutral detergent fiber(NDF)and acid detergent fiber(ADF)in 200CA,300CA and 400CA groups were significantly increased(P<0.05).The rumen effective degradation rate of crude protein(CP)in 200CA and 300CA groups were significantly increased(P<0.05),and that in 400CA group was significantly decreased compared with the control group(P<0.05).2)There were no significant differences in total gas production(72 gas production),pH and microbial protein(MCP)concentration were found among groups(P>0.05).Compared with the control group,the methane(CH_(4))and ammonia nitrogen(NH_(3)-N)concentrations in 200CA,300CA and 400CA groups were significantly decreased(P<0.05).3)There were no significant differences in the concentration of total volatile fatty acids and the proportions of butyrate,isobutyrate,valerate and isovalerate(P>0.05),but the proportion of propionate in 300CA group was significantly increased compared with the control group(P<0.05).To sum up,CA has regulatory effect on the rumen fermentation of meat sheep,it can improve the rumen effective degradation rates of DM,NDF and ADF,increase the retention rate of nitrogen in rumen,and reduce the methane production.The optimal supplemental level of CA is 300 mg/kg diet under the condition of this experiment.