植物精油对泌乳期奶牛生产性能养分消化、瘤胃发酵及氮平衡的影响

Effects of plant essential oils on nutrient digestionperformance,rumen fermentation and nitrogen balance of lactating dairy cows

本研究以泌乳期奶牛为研究对象,研究全混合日粮中补充植物精油对其养分摄入量、表观消化率、瘤胃发酵及氮和能量平衡的影响。试验将泌乳性能一致的16头荷斯坦奶牛随机分为2组,每组8个重复,每个重复1头牛。对照组饲喂基础全混合日粮,处理组饲喂基础全混合日粮+150 mg/kg植物精油,试验为期7周。结果:植物精油组奶牛干物质、有机物、粗蛋白质摄入量及干物质摄入量占体重的比例显著低于对照组(P<0.05)。对照组与植物精油组奶牛干物质、有机物、粗蛋白质和酸性洗涤纤维表观消化率无显著差异(P>0.05),但植物精油组奶牛粗脂肪和中性洗涤纤维表观消化率显著高于对照组(P<0.05)。与对照组相比,植物精油组奶牛瘤胃pH和甲烷产量分别显著降低了2.22%和21.63%(P<0.05),而瘤胃氨氮和丁酸浓度分别显著提高9.67%和9.16%(P<0.05)。对照组与植物精油组奶牛的氮摄入量、尿氮排泄量、乳氮、微生物氮、微生物氮合成效率、净能和消化能摄入量无显著差异(P>0.05)。植物精油组奶牛粪氮排泄量较对照组显著降低11.36%(P<0.05),但泌乳净能显著提高13.22%(P<0.05)。结论:日粮添加植物精油降低了泌乳期奶牛大部分养分摄入量,改善了粗脂肪和中性洗涤纤维表观消化率,提高了瘤胃丁酸浓度,降低了粪氮排泄量,进而可以降低甲烷排放。

This study was conducted to investigate the effects of plant essential oils supplementation on nutrient intake,apparent digestibility,rumen fermentation,and nitrogen and energy balance of lactating dairy cows.Sixteen Holstein dairy cows with the same lactating performance were randomly divided into 2 groups with 8 replicates per group and 1 cow per replicate.The control group was fed a basal total mixed diet,and the treatment group was fed a basal total mixed diet+150 mg/kg essential oil.The experiment lasted for 7 weeks.Results:The intake of dry matter,organic matter,crude protein and the proportion of dry matter intake to body weight of dairy cows in plant essential oil group were significantly lower than those in control group(P<0.05).There were no significant differences in the apparent digestibility of dry matter,organic matter,crude protein and acid detergent fiber between control group and plant essential oil group(P>0.05),but the apparent digestibility of ether extract and neutral detergent fiber in plant essential oil group was significantly higher than that in control group(P<0.05).Compared with the control group,rumen pH and methane production in plant essential oil group were significantly decreased by 2.22%and 21.63%(P<0.05),respectively,while rumen ammonia nitrogen and butyric acid concentrations were significantly increased by 9.67%and 9.16%(P<0.05),respectively.There were no significant differences in nitrogen intake,urinary nitrogen excretion,milk nitrogen,microbial nitrogen,microbial nitrogen synthesis efficiency,net energy and digestible energy intake between control group and plant essential oil group(P>0.05).Compared with the control group,fecal nitrogen excretion in plant essential oil group was significantly decreased by 11.36%(P<0.05),but net milk energy in lactation was significantly increased by 13.22%(P<0.05).Conclusion:Dietary plant essential oils reduced most nutrient intake,but improved apparent digestibility of crude fat and neutral detergent fiber,increased rumen butyric acid concentration and fecal nitrogen excretion,and reduced methane emission.