Currently, the lack of protein source feed has become a pressing issue. Moringa oleifera leaf powder (MOLP) has good potential for the development of protein-derived feeds due to its good protein quality and abundance, but little is known about its effects on broiler growth performance and cecal microbiota. In this study, the chickens were fed different rates of MOLP (1%, 3%, 5%, 7%, and 9%) instead of the rape seed cake, and the effects of different levels of MOLP on growth performance, carcass characteristics, and cecal microbiota of the broilers were evaluated at two different growth stages (day 28 and day 56). In terms of growth performance, the best results were obtained at the 3% MOLP level in the early stages (p < 0.05). In terms of carcass characteristics, in the early stage, the level of 5% MOLP had the best effect; in the later stage, 5% MOLP also had the best effect. In terms of cecal microbial changes, the alpha diversity analysis revealed that 5% MOLP enhanced the richness and diversity of broiler intestinal flora. At the phylum level, the addition of 5% MOLP adjusted the relative abundance of Firmicutes and Bacteroidetes to a level close to that of the A1 group on day 28, while 5% MOLP significantly reduced the relative abundance of Bacteroidetes (p < 0.05) compared to the A2 group on day 56, and the relative abundance of Firmicutes was still higher in the D2 group than in the A2 group (p < 0.05). At the genus level, MOLP addition consistently and significantly increased the relative abundance of Bacteroides (p < 0.05), except for 3% on day 28 and 1% on day 56. For Oscillospira, increasing MOLP levels in the pre- and post-period resulted in a significant decrease in the relative abundance of Oscillospira (p < 0.05). In conclusion, MOLP helps to enhance growth performance and carcass characteristics and improve the cecal microbial structure of broilers. The recommended rate of MOLP addition for broilers is 5% in both the early and late stages.
Keywords: Bacteroidetes; Firmicutes; Moringa oleifera leaf powder; broiler chickens; cecal microbiota; growth performance.