Dai Haonan, Du Dewei, Huang Qi, Guo Jia, Li Shujing, Yu Wenli, Zhao Zengyuan, Sun Peng
State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Shijiazhuang Tianquan Elite Dairy Ltd., Shijiazhuang 050200, China.
Animals (Basel). 2025 Jul 14;15(14):2080. doi: 10.3390/ani15142080.
Our previous study has shown that supplementation of 0.50% benzoic acid (BA) increased growth performance, promoted rumen fermentation, and improved the composition and function of rumen microbiota. This research was designed to conduct a deeper exploration of the impacts of dietary supplementation with BA on the apparent digestibility of nutrients and the composition of rectal microbiota in weaned Holstein dairy calves. Sixteen Holstein heifer calves with similar body weights (91.2 ± 0.7 kg) were selected and randomly allocated into two groups, each comprising eight calves. Calves in the control group (CON group) were fed with a basal diet, while those in the benzoic acid group (BA group) were fed with the basal diet supplemented with 0.50% benzoic acid (on a dry matter basis). The experimental period started at 60 days of age and ended at 102 days of age, lasting for a total of 42 days. The calves were weaned at 60 days of age, with a transition period of 7 days. Feed samples were collected every two weeks, fecal samples were collected from 99 to 101 days of age, and blood samples were collected at 102 days of age. The results showed that supplementation with BA did not influence the digestibility of dry matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, calcium, and phosphorus between the two groups. Compared with the CON group, BA supplementation tended to decrease the total cholesterol (TC) in the serum of the calves ( = 0.067). Supplementation with BA increased the relative abundances of the two beneficial bacteria, and ( < 0.05, LDA > 2), but decreased that of the harmful bacterium, , in the rectum of dairy calves. The microbial functional prediction revealed that the fecal microbial metabolism involved in primary bile acid biosynthesis was higher in the calves from the BA group. In conclusion, the present study demonstrated that adding 0.50% BA to the diet did not influence the apparent nutrient digestibility, but improved rectal microbiota health, which finally promoted the growth performance in weaned Holstein dairy calves.
我们之前的研究表明，添加0.50%的苯甲酸（BA）可提高生长性能、促进瘤胃发酵，并改善瘤胃微生物群的组成和功能。本研究旨在更深入地探讨日粮添加BA对断奶荷斯坦犊牛养分表观消化率和直肠微生物群组成的影响。选择16头体重相近（91.2±0.7千克）的荷斯坦小母牛犊牛，随机分为两组，每组8头。对照组（CON组）犊牛饲喂基础日粮，而苯甲酸组（BA组）犊牛饲喂添加0.50%苯甲酸的基础日粮（以干物质计）。试验期从60日龄开始，至102日龄结束，共持续42天。犊牛在60日龄断奶，过渡期为7天。每两周采集一次饲料样本，在99至101日龄采集粪便样本，在102日龄采集血液样本。结果表明，添加BA对两组犊牛干物质、粗蛋白、乙醚提取物、中性洗涤纤维、酸性洗涤纤维、钙和磷的消化率没有影响。与CON组相比，添加BA使犊牛血清总胆固醇（TC）有降低趋势（P = 0.067）。添加BA增加了犊牛直肠中两种有益菌即[具体菌名1]和[具体菌名2]的相对丰度（P < 0.05，线性判别分析效应大小>2），但降低了有害菌[具体菌名3]的相对丰度。微生物功能预测显示，BA组犊牛粪便微生物参与初级胆汁酸生物合成的代谢更高。总之，本研究表明，日粮中添加0.50%的BA不影响养分表观消化率，但改善了直肠微生物群健康，最终促进了断奶荷斯坦犊牛的生长性能。
