The study was conducted to investigate the effect of forage combination types on rumen methane emissions and nitrogen metabolism of dairy cows. A single factor random block was used in this study.Sixteen Holstein cows were randomly divided into 4 groups which were fed with diet A(forage was composed of corn silage,corn stover),diet B(forage was composed of corn silage,chinensis wildry),diet C(forage was composed of corn silage,corn stover,chinensis wildry), and diet D(forage was composed of corn silage,alfalfa hay,chinensis wildry),respectively.The diets contained corn,wheat bran,molasses beet,corn glut meal,soybean meal,cottonseed meal and corn germ meal. The result showed that:Diet A group had a lower dry matter intake(DMI),gross energy intake(GEI),total nitrogen intake(TNI),compared with the other three diet groups(P<0.05),and diet D group had the highest DMI,GEI and TNI(P < 0.05),its GEI was 11.06%,5.20%and 8.05%higher than that of diet A,B,C group,respectively,and TNI was 14.09%,8.88%and 9.95%higher than that of the other three diets groups,and there was no significant difference between diet B group and diet C group(P>0.05).Diet A group and Diet B group had a higher methane production,methane energy loss,compared with diet C group and diet D group (P<0.05),the methane production of diet A group was 3.36%,6.00% higher than that of diet C group and diet D group,and which of diet B group was 6.41%,9.12% higher than that of diet C group and diet D group,the methane energy loss of diet A group was 3.30% and 6.00%higher than that of diet C group and diet D group,and which of diet B group was 6.35%and 9.13%higher than that of di-et C group and diet D group.Methane production (L)per Megajoule GEI,per kg DMI,and percentage of methane energy to GEI was significantly different between diet A group and diet D group(P<0.05).Fecal N(FN)was similar among treatment groups (P>0.05);however,diet A group trendly had a higher percentage of FN to TNI,compared with diet D group (P=0.071).Urinary N(UN) excretion of diet D group was 18.84%,17.28%and 15.51%higher than that of group A,B,C (P<0.05),however UN/TNI was not affected by diet types (P > 0.05).FN+UN of diet D group was 7.19%,7.19% and 8.35%higher than that of other three diet groups,and (FN+UN)/TNI of diet B group and diet D group was lower than that of diet A group and diet C group (P < 0.05),which of diet B group was 5.58% and 2.33% lower than diet A group and diet C group,and which of group D was 6.04% and 2.80% lower than diet A group and diet C group.The results indicated that mixture of corn stover and chinensis wildry could reduce mehtane emission and N excretion ,and among the most common diet types,the diet including corn sliage,chinensis wildry and alfalfa had lower mehtane emission and N excretion.%为研究不同粗饲料组合类型对奶牛瘤胃甲烷产生量及氮代谢的影响。本试验采用单因素随机区组试验设计，将16头健康荷斯坦干奶牛随机分为4组。以东北地区常用的粗饲料及其组合设计4种粗饲料类型：A组（玉米青贮＋玉米秸秆）；B组（玉米青贮＋羊草）；C组（玉米青贮＋玉米秸秆＋羊草）；D组（玉米青贮＋苜蓿＋羊草）。精饲料由玉米、麦麸、糖蜜、玉米纤维饲料、豆粕、棉籽粕和玉米胚芽饼为主要原料配制。试验结果表明：日粮A组奶牛干物质采食量（DMI）、总能及总氮摄入量均显著低于其他三种类型日粮组（P<0.05），日粮D组最高，其总能摄入量分别较日粮A、B、C组高11.06%、5.20%和8.05%，总氮摄入量分别较日粮A、B、C组高14.09%、8.88%和9.95%，日粮B组与日粮C组差异不显著（P＞0.05）。日粮A、B组奶牛瘤胃甲烷的产生量（L/d）、以甲烷形式损失的能量（MJ/d）显著高于日粮C、D组（P＜0.05），其中日粮A组每天瘤胃甲烷的产生量分别高于日粮C、D组3.36%和6.00%，日粮B组每天瘤胃甲烷的产生量分别高于日粮C、D组6.41%和9.12%，日粮A组以甲烷形式损失的能量分别高于日粮C、D组3.30%和6.00%，日粮B组产生的甲烷能分别高于日粮C、D组6.35%和9.13%。每千克干物质采食量的甲烷产生量（CH4/DMI）、每兆焦总能摄入量产生的甲烷量（CH4/GEI）以及甲烷能占摄入总能的比例（CH4/GEI），日粮B组与日粮C组之间差异不显著（P＞0.05），其他各日粮类型组间差异显著（P＜0.05）。而日粮A组粪氮排放量占总摄入氮的比例有高于日粮D组的趋势（P＜0.10）。日粮D组奶牛尿氮排放量显著高于其他类型日粮组（P＜0.05），分别较日粮A、B、C组高18.84%、17.28%和15.51%，但尿氮排放量占总摄入氮量各组间差异不显著（P＞0.05）。日粮D组奶牛粪氮和尿氮总量显著高于其他三种类型日粮组（P＜0.05），分别较日粮A、B、C组高7.19%、8.35%和6.88%，但日粮B组与日粮D组的粪氮和尿氮总量占总摄入氮量的比例却显著低于日粮A组和日粮C组（P＜0.05），其中日粮B组分别低于日粮A、C组5.58%和2.33%，日粮D组分别低于日粮A、C组6.04%和2.80%。由此可见，玉米秸秆与羊草混合使用时，将降低由玉米秸秆组成的日粮的CH4产量及氮的损失，而在最常用的粗饲料组合类型中，含有羊草与苜蓿的混合日粮向环境排放的CH4及日粮氮损失较少。
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