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

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.

Keywords:

• Beef cattle
• chitin
• real-time PCR
• ruminal microbiology
• dry season supplementation

Acknowledgments

The authors gratefully acknowledge the ‘Coordenação de Aperfeiçoamento de Pessoal de Nível Superior’ (CAPES) and Universidade Federal da Grande Dourados (UFGD) for financial support and fellowships granted. We appreciate the support of the experiment provided by Animal Nutrition of Federal University of Mato Grosso; Cuiabá-MT, and de Embrapa Agrossilvipastoril; Sinop-MT. In addition, the authors express appreciation to Maria Gizelma de Menezes Gressler and Phaena Moraes Faria for their assistance on chemical analyses.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We are grateful to the ‘Conselho Nacional de Desenvolvimento Científico e Tecnológico’ (CNPq) and the ‘Fundacão de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul’ (FUNDECT) for funding of this study.