摘要
The purpose of this study was to investigate the effects of replacing a portion of whole-plant corn silage with straw on the rumen microbial community structure and carbohydrate-active enzyme activity. The experiment employed a single-factor randomized trial design, with eight late-lactation Chinese Holstein dairy cows being randomly divided into two groups of four replicates each. The control group (CS group) was fed a diet consisting of alfalfa silage and a mixture of alfalfa and whole-plant corn silage, while the experimental group (RS group) received a diet in which one-third of the corn silage was replaced with straw while keeping the other components unchanged. The experiment lasted for a total of 21 days, with a pre-feeding period of 14 days and a formal period of 7 days. The rumen fluid collected on day 21 was used for the rumen fermentation parameters and metagenomic analysis. The concentrations of acetic acid, propionic acid, butyric acid, and total volatile fatty acids (TVFA) in the rumen of RS group cows were significantly lower than those in the CS group (p 3.6], p < 0.05). Compared to the CS group, the enzymatic activities of α-L-arabinofuranosidase (EC3.2.1.55), β-xylosidase (EC3.2.1.37), β-glucosidase (EC3.2.1.21), β-glucosylceramidase (EC3.2.1.45), xylanase (EC3.2.1.8), and arabinanase (EC3.2.1.99) in the rumen of RS group cows increased (p < 0.05). According to the correlation analysis, Alistipes, Bacteroides, and Butyrivibrio showed a significant negative correlation with propionic acid (p < 0.05) and a significant positive correlation with the acetic acid-to-propionic acid ratio (p < 0.05). They also showed a significant positive correlation with GH2, GH3, GH20, GH29, GH43, GH78, GH92, CE1, GT4, β-glucosidase (EC3.2.1.21), α-L-arabinofuranosidase (EC 3.2.1.55), β-xylosidase (EC 3.2.1.37), β-glucosylceramidase (EC 3.2.1.45), xylanase (EC 3.2.1.8), and arabinanase (EC 3.2.1.99) (p < 0.05). In summary, straw can not only alter the composition and structure of the rumen microbiota in cows but also affect the relative abundance of CAZymes at different levels within the rumen. Cows may, thus, potentially improve the degradation efficiency of straw diets by increasing the abundance of certain rumen microbiota and enzymes.
摘要译文
这项研究的目的是研究用稻草代替一部分全植物玉米青贮饲料对瘤胃微生物群落结构和碳水化合物活性酶活性的影响。该实验采用了单因素随机试验设计，八个晚分离的中国荷斯坦奶牛被随机分为两组，分别为四个重复。喂食对照组（CS组）饮食，该饮食由苜蓿青贮饲料和苜蓿和全植物玉米青贮饲料的混合物组成，而实验组（RS组）接受了饮食，其中三分之一的玉米青贮饲料被取代。稻草一边使其他组件保持不变。该实验持续了21天，预喂养期为14天，正式期为7天。在第21天收集的瘤胃流体用于瘤胃发酵参数和宏基因组分析。RS组奶牛瘤胃中乙酸，丙酸，丁酸和总挥发性脂肪酸（TVFA）的浓度明显低于CS组的丙酸（P 3.6]，P <0.05）。与CS组相比，α-l-阿拉伯硫代尿苷酶（EC3.2.1.55），β-二基糖苷酶（EC3.2.1.37），β-葡萄糖苷酶（EC3.2.1.21），β-糖基质酶（EC3.2.1.21）的酶活性.2.1.45），木聚糖酶（EC3.2.1.8）和阿拉伯酶（EC3.2.1.99）在RS组母牛的瘤胃中增加（p <0.05）。根据相关分析，ALISTIPES，杀菌剂和丁乙酰基菌与丙酸显着的负相关（P <0.05）和与乙酸酸与丙酸酸比率显着的正相关（P <0.05）。他们还显示了与GH2，GH3，GH20，GH29，GH43，GH78，GH92，CE1，GT4，β-葡萄糖苷酶（EC3.2.1.21），α-L-氨基尿素糖苷酶（EC 3.2.1.55），β.2.1.55），β-2.1.55），表现出显着的正相关性。-Xylosidase（EC 3.2.1.37），β-葡萄糖基酰胺酶（EC 3.2.1.45），木聚糖酶（EC 3.2.1.8）和阿拉伯酶（EC 3.2.1.99）（p <0.05）。总而言之，稻草不仅可以改变母牛中瘤胃菌群的组成和结构，而且还会影响瘤胃内不同水平的cazymes的相对丰度。因此，奶牛可能会通过增加某些瘤胃菌群和酶的丰度来提高草饮食的降解效率。