Abstract

This paper aims to investigate the influence of increasing chitosan doses on the relative proportion and abundance of cellulotytic, amylolytic bacteria, and Archaea transcripts for grazing cattle. Five rumen cannulated crossbread steers [3.6 months and 300 ± 25 kg body LW (live weight), mean ± standard deviation] were used in a 5 × 5 latin square design, randomly assigned to treatment sequence containing chitosan added to 0, 400, 800, 1200, or 1600 mg/kg concentrate. There was the effect of chitosan on the population of Fibrobacter succinogenes, Ruminococcus albus, and Archaea. The lowest population of these bacteria of 576.60 mg/kg DM (dry matter), 1010.40 mg/kg DM, and 634.80 mg/kg DM were noted when chitosan was added at levels of 3.87, 4.16, and 3.52. Except for Ruminococcus albus, which was not affected by increasing chitosan doses, supplementation of this additive in the concentrate quadratically increased the relative abundance of Fibrobacter succinogenes and Archaea Supplemental 740 mg CHI/kg concentrate for grazing steers receiving concentrate at 150 grams/100 kg LW is recommended to promote minimal effect on the relative population and abundance of cellulolytics and amylomatics and to restrict Archaea growth.

摘要

本文旨在研究增加壳聚糖剂量对放牧牛的纤维素分解细菌、淀粉分解细菌和古细菌转录本的相对比例和丰度的影响。五头瘤胃插管杂交面包公牛 [3.6 个月和 300 ± 25 kg 体重 LW（活重），平均值 ± 标准差] 用于 5 × 5 拉丁方设计，随机分配到含有添加到 0、400、800 的壳聚糖的处理序列、1200 或 1600 mg/kg 浓缩物。壳聚糖对Fibrobacter succinogenes、Ruminococcus albus和Archaea的种群有影响. 当以 3.87、4.16 和 3.52 的水平添加壳聚糖时，注意到这些细菌的最低数量为 576.60 mg/kg DM（干物质）、1010.40 mg/kg DM 和 634.80 mg/kg DM。除了不受壳聚糖剂量增加影响的白色瘤胃球菌外，在浓缩物中补充这种添加剂可二次方增加产琥珀酸纤维杆菌和古细菌的相对丰度。补充 740 mg CHI/kg 浓缩物，用于接受 150 克/100 kg LW 浓缩物的放牧阉牛建议促进对纤维素分解物和淀粉酶的相对数量和丰度的最小影响，并限制古细菌的生长。