Effect of increasing doses of chitosan to grazing beef steers on the relative population and transcript abundance of and cellulolytic and amylolytic bacterias.

This paper aims to investigate the influence of increasing chitosan doses on the relative proportion and abundance of cellulotytic, amylolytic bacteria, and 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 , , and . 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 , which was not affected by increasing chitosan doses, supplementation of this additive in the concentrate quadratically increased the relative abundance of and 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 growth.