Changes in rumen fermentation and bacterial community in lactating dairy cows with subacute rumen acidosis following rumen content transplantation

Rumen microbiota intervention has long been used to cure ruminal indigestion in production and recently become a research hotspot. However, how it controls the remodeling of rumen bacterial homeostasis restoration fermentation cows subacute acidosis (SARA) remains poorly understood. This study explored changes communities SARA following content transplantation (RCT). The entire experiment comprised 2 periods: induction period RCT period. During period, 12 ruminally cannulated lactating Holstein were selected allocated into groups at random, fed either conventional diet [CON; n = 4; 40% concentrate, dry matter (DM) basis] or high-grain (HG; 8; 60% DM basis). After began. HG randomly divided groups: donor-recipient (DR) group self-recipient (SR) group, their contents removed completely before RCT. For DR received 70% from CON cows, paired based on comparable body weight; for SR each cow content, self-derived. results showed that nearly all parameters returned normal levels had after 6 d transplantation, regardless concentrations acetate, valerate, total volatile fatty acids (VFA) not recovered whereas them cows. amplicon sequencing indicated both rebuild quickly within 4 RCT, higher level community diversity. At genus level, displayed an improved proportion unclassified Ruminococcaceae Saccharofermentans compared with Correlation analysis between bacteria suggested some potential relationships predominant transplantation-sensitive operational taxonomic units VFA. Co-occurrence network revealed affected only those taxa weak interactions other did affect pivotal high co-occurrence. Our findings indicate contributes suffering without affecting core microbiome.