Analysis of Rumen Degradation Characteristics, Attached Microbial Community, and Cellulase Activity Changes of Garlic Skin and IArtemisia argyi/I Stalk

Garlic skin and Artemisia argyi stalk have broad application prospects as agricultural by-products. However, the current research on them is still relatively limited. Therefore, the focus of this study is to explore the rumen degradation characteristics of these two agricultural by-products, the dynamic changes of surface rumen bacteria and the changes of cellulase activity. Our results showed that garlic skin and Artemisia argyi stalk had good rumen degradability and had different effects on rumen bacteria and cellulase activity (β-glucosidase, endo-β-1,4-glucanase, exo-β-1,4-glucanase and neutral xylanase). The results of these studies can better understand the potential of garlic skin and Artemisia argyi stalk in the rumen of ruminants and provide a scientific basis for the rational utilization and development of agricultural by-products. The purpose of this study was to study the chemical composition, rumen degradation characteristics, surface attached microbial community and cellulase activity of garlic skin (GS) and Artemisia argyi stalk (AS), in order to explain their feeding value. Four 14-month-old healthy Min Dong male goats with permanent rumen fistula were selected as experimental animals. The rumen degradation characteristics of GS and AS were determined by using the nylon bag method, and the bacterial composition, cellulase activity and their relationship on the surface of the two groups were analyzed with high-throughput sequencing of 16S rRNA gene. The results showed that in GS and AS, the effective degradation rate (ED) values of dry matter (DM) were 42.53% and 37.12%, the ED values of crude protein (CP) were 37.19% and 43.38%, the ED values of neutral detergent fiber (NDF) were 36.83% and 36.23%, and the ED values of acid detergent fiber (ADF) were 33.81% and 34.77%. During rumen degradation, the richness and evenness of bacteria attached to the AS surface were higher. At the phylum level, Bacteroidetes and Firmicutes were always the main rumen bacteria in the two groups. At the genus level, fiber-degrading bacteria such as Prevotella, Treponema, and Ruminococcus showed higher levels in GS (p < 0.05). Compared with GS, the activity of β-glucosidase (BG enzyme), endo-β-1,4-glucanase (C1 enzyme), exo-β-1,4-glucanase (Cx enzyme) and neutral xylanase (NEX enzyme) attached to AS surface showed a higher trend. Correlation analysis showed that the relative abundance of Succinivibrio and Rikenellaceae_RC9_gut_group was positively correlated with