苜蓿与玉米混贮质量研究

以玉米与苜蓿为原料,按不同比例混贮;通过发酵品质和营养成分分析,找出二者混贮的适宜配比。结果表明: 1)各混贮处理发酵品质较苜蓿单贮均得到改善,达到优质青贮的目的; 2)玉米与苜蓿3∶7混贮处理CP和Ash含量高于玉米单贮,低于苜蓿单贮,差异显著(P＜0.05),而NDF和ADF含量低于玉米单贮,高于苜蓿单贮,差异显著(P＜0.05);3)玉米与苜蓿5∶5、7∶3混贮处理pH值较苜蓿单贮显著降低(P＜0.05);各混贮处理乳酸占总酸百分比均达到60%以上,乙酸、丙酸占总酸百分比较苜蓿单贮降低,丁酸产生较少; 4)苜蓿青贮后乳酸菌数达到10⁸ cfu/g FM,玉米青贮前后乳酸菌数差异不明显,青贮后各处理大肠杆菌数明显下降。7∶3混贮处理发酵品质最佳。

A study on quality of mixed silage of alfalfa and corn

To assess the best ratio for mixed silage of corn and alfalfa,they were mixed and ensiled in different proportions(0∶10,3∶7,5∶5,7∶3,10∶0 respectively) and after 30 days,the nutrition and fermentation quality of all treatments were determined and analyzed.1) Compared with alfalfa silage,all three treatment improved fermentation quality and attained the goal of excellent silage.2) CP(crude protein) and Ash(crude ash) contents of the 3∶7 treatment were significantly higher than corn but lower than alfalfa silage(P<0.05),NDF(neutral detergent fiber) and ADF(acid detergent fiber) contents were significantly lower than corn but higher than alfalfa silage(P<0.05).3) pH values of the 5∶3 and 7∶3 treatments were significantly lower than that of alfalfa silage(P<0.05).Lactic acid contents of all three mixed treatments reached more than 60%,but the contents of acetic acid and propionic acid reduced,and produced little butyric acid compared with alfalfa silage.4) The number of lactic acid bacteria on alfalfa silage increased to 108 cfu/g FM after ensilling,while that on corn silage stayed the same before and after fermentation.Escherichia coli of mixed silage decreased significantly after ensilling.The mixed treatment modulated silage of high quality more easily,and the nutrition and fermentation quality of mixed silages were between corn and alfalfa silage.The fermentation quality of the 7∶3 treatment was the best.