添加玉米粉对盐碱地和非盐碱地紫花苜蓿青贮品质和微生物多样性的影响

Effects of Corn Flour Addition on the Quality Alfalfa Silage and Microbial Diversity in Saline-alkali and Non-salinealkali Lands

试验设置盐碱地紫花苜蓿单贮(SM0),盐碱地紫花苜蓿+10%玉米粉(SM10),非盐碱地紫花苜蓿单贮(NSM0),非盐碱地紫花苜蓿+10%玉米粉(NSM10),检测并分析各组发酵60 d后青贮饲料营养成分、青贮品质和微生物多样性。结果显示,盐碱地较非盐碱地紫花苜蓿青贮饲料可溶性碳水化合物、中性洗涤纤维、酸性洗涤纤维含量高,粗蛋白、粗灰分含量低;非盐碱地较盐碱地紫花苜蓿青贮饲料乳酸、乙酸含量高,丁酸含量以及氨态氮/总氮低(P<0.05),V-score评分增加,发酵品质提高。添加玉米粉后,盐碱地和非盐碱地紫花苜蓿青贮料中干物质、可溶碳水化合物与乳酸含量显著升高,丁酸含量及氨态氮/总氮显著降低(P<0.05)。盐碱地紫花苜蓿鲜草中乳杆菌属、魏斯氏菌属、肠球菌属相对丰度高于非盐碱地;添加玉米粉增加了二者青贮中乳杆菌属和肠球菌属相对丰度,降低了魏斯氏菌属和梭菌属相对丰度。综上,非盐碱地苜蓿青贮品质优于盐碱地,添加玉米粉改变了微生物群落结构,进而有效地改善了盐碱地和非盐碱地紫花苜蓿青贮发酵品质。

There were four silage experiments in the present study,including alfalfa silage collected from saline-alkali land(SM0),alfalfa silage collected from saline-alkali land with the addition of 10% corn flour(SM10),alfalfa silage collected from non-saline-alkali land(NSM0),alfalfa silage collected from nonsaline-alkali land with the addition of 10%corn flour(NSM10).After 60 d of fermentation,the chemical composition,fermentation quality and microbial diversity of alfalfa silage collected from both saline-alkali and non-saline-alkali lands were measured.The results showed that alfalfa silage collected from salinealkali land exhibited higher levels of soluble carbohydrate,neutral detergent fiber and acid detergent fiber compared to silage collected from non-saline-alkali land.Conversely,the content of crude protein and crude ash in the saline-alkali land silage was lower than that in the non-saline-alkali land silage.Alfalfa silage collected from non-saline-alkali land exhibited higher V-score and levels of lactic acid and acetic acid compared to silage collected from saline-alkali land.While the content of butyric acid and ammonia nitrogen/total nitrogen in the non-saline-alkali land silage was lower than that in the saline-alkali land silage(P<0.05),indicating the improved fermentation quality.After the addition of corn flour,the contents of dry matter,soluble carbohydrate,and lactic acid exhibited a significant increase in both saline-alkali and non-saline-alkali land alfalfa silage,while there was a significant decrease(P<0.05)in butyric acid content and ammonia nitrogen/total nitrogen.The fresh alfalfa from saline-alkali land exhibited higher relative abundances of Lactobacillus,Weissella,and Enterococcus compared to that from non-saline-alkali land.Following the adding of corn flour,the relative abundances of Lactobacillus and Enterococcus in both saline-alkali and non-saline-alkali land alfalfa silage increased,while the relative abundances of Weissella and Clostridium decreased.In conclusion,the quality alfalfa silage from non-saline-alkali land was found to be superior to that from saline-alkali land.The adding of corn flour proved effective in improving the quality of alfalfa silage collected from both saline-alkali and non-saline-alkali lands by altering the microbial community structure.