Effects of energy sources and inclusion levels of concentrate in sugarcane-silage-based diets of finishing Nellore young bulls: Nutrient digestibility, rumen metabolism and ecosystem

Autor(es)

Ferrari, V. B. ^[1] ; Consolo, N. R. B. ^[2] ; Sousa, R. T. ^[1] ; Souza, J. M. ^[1] ; Bueno, I. C. S. ^[2] ; Silva, L. F. P. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med, Dept Anim Sci, 225 Duque Caxias Norte, BR-13635900 Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Fac Anim Sci & Food Engn, Dept Anim Sci, 225 Duque Caxias Norte, BR-13635900 Pirassununga, SP - Brazil

^[3] Univ Queensland, 306 Carmody Rd, Bld 80, St Lucia, Qld 4072 - Australia

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF AGRICULTURAL SCIENCE; v. 157, n. 4, p. 357-364, MAY 2019.
• Citações Web of Science: 0

Resumo

Intake in sugar-rich diets can be limited either via rumen fill or excessive rumen fermentation and source of non-fibre carbohydrate (NFC) in the diet can affect both factors. The aim of the current study was to quantify the effect of partially replacing ground maize (GM) with steam-rolled maize (SRM) or pelleted citrus pulp (PCP) at two concentrate levels in sugarcane-based diets on digestibility, rumen ecosystem and metabolism of Nellore steers. Six rumen-cannulated steers were assigned to a 6 x 6 Latin square, replicated in time, in a 2 x 3 factorial arrangement of treatments with two levels of concentrate (600 or 800 g concentrate/kg dry matter {[}DM]) and three NFC sources. Each steer within a period was considered an experimental unit. Feeding more concentrate increased total tract digestibility of organic matter and decreased fibre intake and passage rate. It also reduced rumen populations of Fibrobacter succinogenes and Streptococcus bovis and increased Ruminococcus flavefaciens. Substituting PCP for GM increased rumen pH, acetic acid and organic matter digestibility. Feeding PCP also reduced R. flavefaciens and R. amylophilus rumen populations. Substituting SRM for GM increased starch digestibility and rumen propionic acid, but decreased rumen ammonia concentration. Feeding SRM increased rumen populations of Megasphaera elsdenii with the high-concentrate diet but reduced Ruminococcus albus populations at both concentrate levels. In conclusion, partial replacement of GM by PCP decreased intake in sugar-rich diets, while increasing total tract neutral detergent fibre digestibility. Replacement of GM with SRM increases rumen fermentation and total tract digestibility of starch. (AU)

• Processo FAPESP: 12/12125-0 - Efeito de fontes de carboidratos não fibrosos sobre o ganho de peso, consumo, características da carcaça, cinética e ecossistema ruminal de tourinhos em terminação
• Beneficiário: Luis Felipe Prada e Silva
• Linha de fomento: Auxílio à Pesquisa - Regular