Alfalfa Hay Supplementary Intake is Advancing Effect To Rumen Fermentation and Microbial Function of Gansu Alpine Fine Wool Sheep During Cold Season

Abstract Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. The objective of our research was to assess the role of Alfalfa hay supplementary intake in roughage in ewes’ rumen fermentation and microbial function. 120 ewes were allocated randomly into 4 groups, and were fed with different level of alfalfa hay, respectively. Individual ewes’ bodyweight, blood biochemical indexes and rumen microbial characteristics were analyzed after the end of feeding trials. The results showed that alfalfa hay supplementary could significantly enhance sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (P < 0.05). Meantime, alfalfa hay supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. The ruminal fluid microbiota of alfalfa hay supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. Overall, the study suggested that there was an increasing tendency of alfalfa-hay-supplementary group in 30% Yellow Maize Silage + 70% Alfalfa Hay roughage in body weight, ruminal fermentation and microbial function, which improved GS performance through developing hay supplementary system during cold season.