title: Parameters of fermentation and rumen microbiota of Nellore steers fed with different proportions of concentrate in fresh sugarcane containing diets.
abstract: The objective of this study was to evaluate the effect of a fresh sugarcane-based diet and different roughage-to-concentrate ratios (70:30, 60:40, 40:60 and 20:80) on the rumen microbiota associated with rumen fermentation parameters and the intake and apparent digestibility of nutrients in Nellore steers. Eight rumen-cannulated Nellore steers (331 ± 8 kg BW) were distributed in a double 4 × 4 Latin square design balanced for the control of the residual effect. The ruminal pH decreased (p < 0.01) and the concentrations of N-NH3, isovaleric and valeric acids increased linearly (p < 0.05) with an increase dietary concentrate level. Furthermore, an increased concentrate proportion reduced the population of Fibrobacter succinogenes and Ruminococus flavefaciens (p < 0.01) and increased the population of Selenomonas ruminantium and Megasphaera elsdenii (p < 0.01). The protozoa count revealed a predominance of the genus Entodinium. The synthesis of microbial N [g/d] and the efficiency of microbial synthesis [g of microbial N/kg of organic matter apparently digested in the rumen] increased as the proportion of concentrate was increased (p < 0.05). Therefore, it can be concluded that an increasing proportion of concentrate in sugarcane-containing diets enhances the synthesis of microbial protein and does not alter the fibre digestibility, although the population of fibre fermenting bacteria was reduced.
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Carlos S
authors.initials: CS
authors.lastname: Ribeiro Júnior
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Juliana D
authors.initials: JD
authors.lastname: Messana
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Yury T
authors.initials: YT
authors.lastname: Granja-Salcedo
authors.affiliation: b Centro de Pesquisas em Pecuária de Corte , Instituto de Zootecnia , São Paulo , Brazil.
authors.forename: Roberta C
authors.initials: RC
authors.lastname: Canesin
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Giovani
authors.initials: G
authors.lastname: Fiorentini
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Elias
authors.initials: E
authors.lastname: San Vito
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Furlan
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.|c Departamento de Zootecnia , Membro INCT/CA - UFV , Viçosa , Minas Gerais , Brazil.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Reis
authors.affiliation: a Faculdade de Ciências Agrárias e Veterinárias, Departamento de Zootecnia , Universidad Estadual Paulista , São Paulo , Brazil.|c Departamento de Zootecnia , Membro INCT/CA - UFV , Viçosa , Minas Gerais , Brazil.
authors.forename: Telma T
authors.initials: TT
authors.lastname: Berchielli
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects; D000818:Animals; D002417:Cattle / Q000382:microbiology* / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects; D005285:Fermentation / Q000187:drug effects; D000069196:Gastrointestinal Microbiome / Q000502:physiology*; D008297:Male; D009753:Nutritive Value; D012417:Rumen / Q000382:microbiology / Q000502:physiology; D031786:Saccharum / Q000737:chemistry*
keywords: Bacteria; digestibility; microbial protein; protozoa; rumen fermentation; steers; sugarcane