Autoria: HOFFMANN, A.; CARDOSO, A. S.; FONSECA, N. V. B.; ROMANZINI, E. P.; SINISCALCHI, D.; BERNDT, A.; RUGGIERI, A. C.; REIS, R. A.

Resumo: The inclusion of corn-dried distillers? grains (DDG) could be an alternative supplement to increase animal performance, nitrogen efficiency usage (NEU), and decrease enteric methane (CH4) emissions. Our goal was to determine whether DDG could replace a traditional supplement (cottonseed meal) without affecting animal performance, N balance, and CH4 emissions. The experiment was conducted during the forage growing season (December to April), with 15 d adaptation, and a 112 d experimental period. The experimental design was completely randomized with four treatments: a mineral supplement (MS), cottonseed meal supplement (CS), 50% replacement of CS by DDG (50DDG), and 100% replacement of CS by DDG (100DDG). Cottonseed meal and DDG were used as protein supplement. A total of 12 paddocks, 3 per treatment,were used to measure forage mass:morphological and chemical composition of forage, forage allowance, and animal performance. Six animals per treatmentwere used to evaluateDMintake, digestibility, CH4 emissions, microbial protein production (MCP), and NEU of each treatment. Eighty-one Young Nellore bulls (48 testers, 12 per treatments and 33 adjusters) with initial BWof 255±5 kg (10?12 months old) were supplementedwith each supplement type at a level of 0.3% of BW. Pasture managementwas continuous stocking with a variable stocking rate (put-and-take). Enteric CH4 was measured using the gas tracer technique. TheMCPwas quantified using purine derivatives and the NEU mass balance. No differences were found in nutrient intake (P > 0.228). Individual animal performance and gain per area were higher in the treatments with concentrates compared with that of MS; however, there was no difference among treatments CS, 50DDG, and 100DDG. The ADGwas 0.83 for MS and 1.08 kg/animal/dwhen supplemented (P < 0.05). Gain per hectare was 709 kg/ha for MS and 915 kg/ha when supplemented with concentrates (P <0.05). There was no difference in CH4 production among treatments that average 180 g/animal/d; however, CH4 per kg of gain was reduced with CS. The CH4 conversion factor averaged 5.91%. There was no difference in the synthesis ofMCP and NEU. Corn DDG can replace 100% of cottonseedmeal as a protein source for supplementation of young Nellore bulls grazing in tropical pastures without affecting animal performance, NEU, MCP, and CH4 emissions.

Ano de publicação: 2021

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Pecuária Sudeste

Palavras-chave: Beef cattle, Brachiaria, Diet supplementation, Nitrogen efficiency use, Pasture management