体外产气法评定玉米青贮、苜蓿、燕麦、花生秧的组合效应

Evaluation of Associative Effects of Corn Silage,Alfalfa Hay,Oat Hay and Peanut Vine by In Vitro Gas Production Method

试验旨在通过体外产气法探究相同精粗比下(C:R)全株玉米青贮、苜蓿、燕麦草及花生秧配比间的组合效应,以期筛选出奶牛日粮中粗饲料的最优组合比例。本试验按C:R=60:40配制8种不同组合的饲粮,各组合精料均为玉米:豆粕:麸皮:预混料=60:15:15:10,粗饲料原料组合分别为组合1(苜蓿:全株玉米青贮=2:2)、组合2(苜蓿:全株玉米青贮=1:3)、组合3(单一全株玉米青贮)、组合4(苜蓿:全株玉米青贮:燕麦草=1:2:1)、组合5(苜蓿:全株玉米青贮:花生秧=1:2:1)、组合6(全株玉米青贮:燕麦草=2:2)、组合7(全株玉米青贮:花生秧=2:2)、组合8(全株玉米青贮:燕麦草:花生秧=2:1:1)。试验应用Menke体外产气法分别在2、4、8、12、16、24、32、40、48、56、64 h和72 h测定其产气量、产气速度,并于24 h测定发酵液pH、氨态氮(NH3-N)浓度和微生物蛋白(MCP)产量。结果表明,组合8在0~72 h时的产气量在数值上为各组最高,累计产气量显著高于组合1和组合3(P<0.05),但产气速度各组间差异不显著(P>0.05)。各组间24 h发酵液存在显著差异(P<0.05),但均处于瘤胃发酵正常范围。综上所述,在本试验条件下,C:R=60:40时,不同组合比例的粗饲料饲粮体外发酵72 h,粗料组合为全株玉米青贮:燕麦草:花生秧=2:1:1时可有效提高瘤胃发酵水平,更大程度地发挥饲料营养成分互补的优势。

The purpose of this experiment was to evaluate the associative effects of whole corn silage,alfalfa hay,oat hay and peanut vine under the same concentrate to forage ratio by in vitro gas production method,in order to select the optimal combination ratio for dairy cattle.In this experiment,8 different combinations of diets were formulated according to concentrate∶roughage=60∶40.The concentrate of each combination was corn∶soybean meal∶bran∶premix=60∶15∶15∶10,and the roughage material combinations were combination 1(alfalfa hay∶whole corn silage=2∶2),combination 2(alfalfa hay∶whole corn silage=1∶3),combination 3(whole corn silage),combination 4(alfalfa hay∶whole corn silage∶oat hay=1∶2∶1),combination 5(alfalfa hay:whole corn silage∶peanut vine=1∶2∶1),combination 6(whole corn silage∶oat hay=2∶2),combination7(whole corn silage∶peanut vine=2∶2),combination 8(whole corn silage∶oat hay∶peanut vine=2∶1∶1).Gas production and gas production rate were measured at 2,4,8,12,16,24,32,40,48,56,64 and 72 h by Menke in vitro gas production method,pH,NH3-N and MCP of fermentation liquid was measured at 24 h.The results showed as follows:the gas production of combination 8 at 0 to 72 h was the highest in numerical terms,and the cumulative gas production was significantly higher than that of combination 1 and combination 3(P<0.05),but there was no significant difference in gas production rate among all groups(P>0.05).There were significant differences in pH values of 24 h fermentation solution(P<0.05),but all of them were in the normal range of rumen fermentation.In conclusion,under the conditions of this experiment,when C:R=60:40,the roughage diets with different combination proportions were fermented for 72 h in vitro,and the combination effect of the roughage combination with whole corn silage∶oat hay∶peanut vine ratio=2:1:1 was the best.This combination can effectively improve the rumen fermentation level and give full play to the advantages of dietary nutrient complement to a greater extent.