Effects of dietary rumen-degradable protein on growth performance, nitrogen metabolism, and rumen microbiome in dairy buffalo heifers

Introduction: Buffaloes are globally important dairy animals, but their low feed nitrogen utilization efficiency and excessive dietary rumen-degradable protein (RDP) results in aggravated nitrogen pollution and high breeding costs. Studies on the optimal RDP levels for 7-10-month-old dairy buffalo heifers remain scarce, limiting precise nutritional management. Materials and methods: = 6 heifers/group, with one heifer in each replicate; Dietary RDP: 60.85-88.90 g/kg). The 73-day trial (15-day adaptation) included measurements of growth performance, nitrogen metabolism, serum indices, rumen parameters, and microbiome (16S rRNA/ITS sequencing). Results: < 0.05), along with the presence of group-specific taxa. Discussion: An optimal dietary RDP level for 7-10-month-old dairy buffalo heifers was 67.31 g/kg, which improved the ADG and nitrogen utilization efficiency without compromising health, while also altering the rumen microbial structure. Therefore, when formulating diets for buffaloes, it is advisable to consider to note only meet the DCP requirements but also appropriately regulate the dietary RDP levels.