Effects of rosemary extract and its residue on gut microbiota in geese

With the implementation of antibiotic bans and the continuous rise in feed prices, the cost of farming has sharply increased. It is urgent to identify natural plant ingredients that can improve animal growth performance. Previous studies have demonstrated that rosemary extract (RE) positively affects animal production performance. Furthermore, the rosemary residue (RR) after extraction retains residual carnosol, carnosic, and rosmarinic acids. Currently, there is a lack of effective ways to utilize RR, which is often directly discarded. Geese are important poultry in China, and their meat provides high-quality protein to humans. Based on this, the effects of RE and RR on geese production, immune performance and gut microbiota were studied.