不同小麦秸秆切碎长度及加工程度对奶牛干物质采食量、产奶量及消化率的影响

Effects of different cut length of wheat silage on feed intake,milk production and digestibility of dairy cows

文章旨在研究小麦秸秆青贮后,通过不同的切碎长度及加工程度对奶牛干物质采食量、产奶量及消化率的影响。试验选择产奶期在70 d的荷斯坦奶牛24头,采用4×4拉丁方设计试验,试验全混合日粮为4种,每组日粮饲喂6头奶牛,每头奶牛为1个重复。对照组切碎长度为0.95 cm(未做任何处理),处理1组切碎长度为0.95 cm(1 mm碾压),处理2组切碎长度为1.45 cm(1 mm碾压),处理3组切碎长度为1.90 cm(1 mm碾压),试验共进行28 d。处理1组和处理2组小麦秸秆中性洗涤纤维和酸性洗涤纤维均较对照组和处理3组低。处理1组小麦秸秆淀粉含量最高,达到25.8%。处理1组小麦秸秆乳酸和乙酸含量高于其他各组。小麦秸秆的切碎长度显著影响奶牛中性洗涤纤维采食量及每千克体重中性纤维采食量(P<0.05)。处理组较对照组显著提高了产奶量、4%脂肪校正乳及乳脂含量(P<0.05)。青贮小麦秸秆的切碎长度显著影响中性洗涤纤维表观消化率,其中处理1组最低(P<0.05)。青贮小麦秸秆切碎长度和加工程度显著影响酸性洗涤纤维表观消化率,对照组最高(P<0.05),处理1组最低(P<0.05)。对照组和处理3组较处理1组和处理2组显著提高了瘤胃丁酸含量(P<0.05)。综上所述,小麦秸秆的切碎长度对奶牛产奶性能无显著影响,但切碎长度为1.9 mm时可以改善瘤胃的发酵性能。

This study was to evaluate the different cut length of wheat silage on feed intake,milk production and digestibility of dairy cows.Twenty-four multiparous Holstein cows averaging 71 d in milk at trial initiation were in a replicated 4×4 Latin square design with 28-d periods.The control diet was untreated with wheat silage 0.95 mm cut length,the treatment 1 diet(T1)was processed with 1 mm roll clearance with wheat silage 0.95 mm,the T2 diet was processed with 1 mm roll clearance with wheat silage 1.45 mm cut length,the T3 diet was with 1 mm roll clearance with wheat silage 1.90 cut length,and the trial last 28 d.The ADF and NDF in T1 and T2 wheat silage were lower than that of the control group and T3.The starch contents in T1 was the highest,which reached to 25.8%.The lactic and acetic contents in T1 were higher than the other groups.The cut length of wheat silage signifi cantly affected the digestibility of NDF,which was the lowest in T1(P<0.05).The cut length of wheat silage and process signifi cantly affect the digestibility of ADF,which was the highest in the control group(P<0.05),and the lowest in T1(P<0.05).The butyrate contents in rumen of the control and T3 groups were higher than that of T1 and T2 groups(P<0.05).In conclusion,the cut length of wheat silage within process had little effect on lactation performance of dairy cows,while the 1.90 cut length of wheat silage can improve the rumen fermentation.