不同处理方式对籽粒苋青贮品质的影响

Effects of addition of lactic acid bacteria,glucose,and formic acid on the quality of Amaranthus hypochondriacus silage

试验以籽粒苋为材料,在青贮中分别添加乳酸菌制剂、葡萄糖和甲酸3种添加剂,研究不同的处理方式对籽粒苋青贮动态发酵品质以及营养成分的影响,以明确青贮添加剂对粒苋青贮的作用,为籽粒苋青贮饲料的合理利用提供研究途径。试验设5个处理组:对照组,不加任何添加剂;乳酸菌制剂组,按1kg乳酸菌制剂调制3~4t籽粒苋鲜草装罐;葡萄糖组,添加量为30g/kg;乳酸菌制剂和葡萄糖组,添加量与单独添加时一致;甲酸组,添加量为5g/kg。在发酵第1,3,9,30和57天分别开罐取样,检测样品中pH、乳酸、氨态氮、干物质、粗蛋白和中性洗涤纤维等指标。结果表明,在籽粒苋青贮同时加入乳酸菌制剂和葡萄糖可以快速发酵,产生大量乳酸,迅速降低青贮pH值,显著降低乙酸、中性洗涤纤维含量和氨态氮/总氮(P<0.05),并能显著提高干物质和粗蛋白含量(P<0.05);加入甲酸可以显著降低乙酸含量(P<0.05),对干物质含量没有明显影响(P>0.05)。综上所述,籽粒苋通过制作青贮饲料可以保存营养成分,与籽粒苋自然青贮相比,籽粒苋青贮时加入上述青贮添加剂均可不同程度的改善青贮品质,同时加入乳酸菌和葡萄糖对青贮改善效果最佳。

The aim of this research was to optimize the method for making Amaranthus hypochondriacus silage.We tested the effects of adding lactic acid bacteria,glucose,and formic acid on the fermentation quality and nutritional composition of A.hypochondriacus silage.The five treatments were as follows:control(no additives),lactic acid bacteria group(lactic acid bacteria added at 0.25-0.33g/kg),glucose group(glucose added at 30g/kg),lactic acid bacteria+glucose group(added at the same levels as in individual treatments)and formic acid group(formic acid added at 5g/kg).Silos containing each treatment were opened on days 1,3,9,30,and 57,and the pH and the contents of lactic acid,ammonia nitrogen,total nitrogen,lactic acid,acetic acid,dry matter,crude protein,and neutral detergent fiber in the ensiling samples were determined.The results showed that the additions accelerated the fermentation process.The addition of glucose and lactic acid bacteria to A.hypochondriacus silage resulted in greater fermentation,more lactic acid,and lower pH values.These additions also significantly reduced the contents of acetic acid and neutral detergent fiber and the ammonia nitrogen∶total nitrogen ratio(P<0.05),and significantly increased the contents of dry matter and crude protein(P<0.05).Adding formic acid markedly decreased the acetic acid content(P<0.05),but did not affect the dry matter content(P>0.05).We concluded that the nutritional composition of A.hypochondriacus can be preserved by making silage.Our results showed that addition of lactic acid bacteria,glucose,and formic acid can improve the quality of A.hypochondriacus silage,and that the best results were obtained by adding lactic acid bacteria and glucose.