青稞酒糟对紫花苜蓿和多年生黑麦草混合青贮发酵品质的影响

[目的] 本文旨在研究添加不同比例的青稞酒糟对紫花苜蓿(Medicago sativa L.)和多年生黑麦草(Lolium perenne L.)(质量比为3:7)混合青贮发酵品质的影响。[方法] 试验设对照组(CK)与10%(PAW10)、20%(PAW20)和 30%(PAW30)青稞酒糟添加水平处理组,分别在青贮后7、14、30和60 d打开实验室青贮窖,取样分析青贮饲料发酵品质。[结果] 与对照相比,青稞酒糟添加组提高了乳酸含量,降低了pH值,其中PAW20和PAW30处理组的乳酸含量显著升高(P<0.05),pH值显著降低(P<0.05);乙酸含量随着青稞酒糟添加比例的增加而逐渐降低,各处理组乳酸/乙酸高于对照组,青贮饲料以同型乳酸发酵为主;各处理组丙酸和丁酸含量较低(小于2 g？kg-1),氨态氮/总氮值显著低于(P<0.05)对照组。青稞酒糟提高了混合青贮饲料的发酵品质,降低了水溶性碳水化合物的损失。[结论] 添加青稞酒糟可以提高青贮饲料发酵品质,以添加20%青稞酒糟较为适宜。
[Objectives] The objective of this study was to evaluate the effects of adding different ratios of wet hulless barley distillers’ grains(WHBDG) on the fermentation qualities of mixed ensilage of alfalfa(Medicago sativa L.)and perennial ryegrass(Lolium perenne L.)(3:7). [Methods] The treatments were as follows:control(without WHBDG)and three treatments of different WHBDG addition rations(10%,20%,30% of fresh weight). These silos were opened 7,14,30 and 60 days after ensiling and the fermentation quality was analyzed. [Results] The results showed the WHBGD improved the mixed silage fermentation quality,as indicated by a sharp accumulation of lactic acid(LA),faster decline of pH,and the treatments of PAW20 and PAW30 markedly increased the concentrations of LA and decreased pH when compared with the control. The content of acetic acid was gradually decreasing with the WHBDG ratio increasing,and the lactic acid/acetic acid of treatments was higher than that of control,indicating the homofermentative lactic bacteria held a dominant position in the silage. The contents of propionic acid and butyric acid of treatments were very low(<2 g？kg-1)and the ammonia nitrogen/total nitrogen of them was lower than that of control. These results indicated that WHBDG addition effectively reduced the loss of water soluble carbohydrate. [Conclusions] Taking fermentation quality and rational utilization of resources into account,it was suggested that PAW20 treatment was the most suitable choice