蒸汽压片玉米对奶牛生产性能和氮磷排放影响的研究

本试验旨在研究蒸汽压片玉米对泌乳早期中国荷斯坦奶牛生产性能和氮磷排放的影响.试验采用4×4重复拉丁方设计.将8头泌乳早期中国荷斯坦奶牛随机分为4组,每组2头.4种日粮处理中蒸汽压片玉米含量分别为精料的0、10%、20%和30%.试验分4期,每期28 d.结果表明:日粮中添加蒸汽压片玉米对奶牛干物质采食量无显著影响(P＞0.05),但显著提高了饲料转化率(奶料比)(P＜0.05);显著提高了奶牛产奶量,其中20%与30%组的4%标准奶产量(FCM)产量分别比对照组提高2.78和2.87 kg·d~(-1)(P＜0.01).对乳成分无显著影响(P＞0.05);乳蛋白、乳糖、乳非脂固形物含量呈增加趋势;对营养物质的表观消化率无显著影响(P＞0.05);日粮中添加蒸汽压片玉米显著降低了乳尿素氮水平(P＜0.05).试验组奶牛氮排放量分别比对照组降低了4.23%(P＞0.05)、9.37%(P＜0.05)和10.29%(P＜0.05),磷排放量分别比对照组降低了1.93%(P＞0.05)、2.59%(P＞0.05)和5.19%(P＞0.05).因此,饲喂蒸汽压片玉米能够有效提高奶牛的生产性能,降低氮磷的排放.

Effects of Steam-Flaked Corn on the Production Performance and Excretion of Nitrogen and Phosphorus in Dairy Cows

The experiment was conducted to study the effects of steam-flaked corn (SFC) in the diet on the performance and the excretion of nitrogen and phosphorus in dairy cows, using a 4× 4 replicated Latin square design. Steam-flaked corn contents in the experimental ration were dividedly 0%, 10%, 20% or 30% of the concentrate. There were four 28-d experimental periods. The results indicated that dry matter intake was unaffected by diet (P＞0.05), but steam-flaked rather than dry-ground corn (DGC) in diets could significantly increase the feed efficiency (4%FCM/DMI) (P＜0. 05). Milk yield was increased (P＜0. 05) for cows fed SFC diet compared with cows fed DGC diet. FCM yield for cows fed concentrate diets containing 20% or 30% SFC was separately significantly increased 2.78(P＜0.01) and 2. 87 kg· d~(-1) (P＜0.01) than the control diet. The percentages of milk fat, protein, lactose and non-fat solid (SNF) were unaffected by diet(P＞0.05), but tended to increase except milk fat; The apparent digestibility of nutrients were unaffected by diet(P＞0.05). The MUN were decreased (P＜0.05) for cows fed SFC diets.Comparing with the control group (0%SFC), the excretion of nitrogen of the cows fed with the SPC diets were decreased by 4.23% (P＞0.05),9.37% (P＜0.05)and 10.29% (P＜0.05),and the excretion of phosphorus were decreased by 1.93%(P＞0.05),2.59%(P＞0.05)and 5.19% (P＞0.05), respectively. In conclusion, compared with DGC diet, SFC diet had decreased the excretion of nitrogen and phosphorus while the performance was significantly increased.