Combining Marandu grass grazing height and supplementation level to optimize growth and productivity of yearling bulls

Autor(es)

Barbero, R. P. ^[1] ; Malheiros, E. B. ^[1] ; Araujo, T. L. R. ^[2] ; Nave, R. L. G. ^[3] ; Mulliniks, J. T. ^[4] ; Berchielli, T. T. ^[2] ; Ruggieri, A. C. ^[2] ; Reis, R. A. ^[2]

Afiliação do(s) autor(es)

^[1] UNESP Univ Estadual Paulista, Dept Ciencias Exatas, Fac Ciencias Agr & Vet, BR-14884900 Jaboticabal, SP - Brazil

^[2] UNESP Univ Estadual Paulista, Dept Zootecnia, Fac Ciencias Agr & Vet, BR-14884900 Jaboticabal, SP - Brazil

^[3] Univ Tennessee, Dept Plant Sci, Knoxville, TN 37996 - USA

^[4] Univ Tennessee, Dept Anim Sci, Knoxville, TN 37996 - USA

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL FEED SCIENCE AND TECHNOLOGY; v. 209, p. 110-118, NOV 2015.
• Citações Web of Science: 11

Resumo

Two experiments were conducted to determine the effects of grazing height and supplementation levels of Marandu pastures on average daily gain (ADG), gain per hectare (GPH) and methane (CH4) emissions during the wet season under continuous stocking by Nelore yearling bulls. Exp. 1: three grazing heights were evaluated: 15, 25 and 35 cm, combined with 0.3% of BW of a supplement (161 g crude protein (CP)/kg and 20.1 MJ gross energy (GE)/kg on dry matter basis (DMB)). Experimental design was completely randomized (three paddocks per treatment), and the effects were analyzed by polynomial orthogonal contrasts. Exp. 2: grazing heights were combined with decreasing supplementation levels as grazing heights increased: short height (15 cm) and high supplementation (0.6% of BW of a supplement: 142 g CF/kg and 18.9 MJ GE/kg on DMB) (SHHS); moderate height (25 cm) and moderate supplementation (0.3% of BW of a supplement: 161 g CP/kg and 20.1 MJ GE/kg on DMB) (MHMS) or tall height (35 cm) without supplementation) (THWS). Experimental design was completely randomized (three paddocks per treatment), and treatment means were compared by Tukey test (P<0.05). In Exp. 1, ADG increased linearly (P=0.02), and GPH decreased linearly (P=0.0002) as grazing height increased. Methane emission was not affected (P=0.64) by grazing height. In Exp. 2, ADG was not influenced (P=0.14) by treatments. However, GPH was the greatest (P<0.0001) for the SHHS treatment. In addition, CH4 emissions were lower (P<0.0001) in SHHS and MHMS bulls compared to THWS. The SHHS can improve the GPH without decreasing the ADG of each individual animal. Optimizing supplementation level according to grazing pressure may improve the nutrition efficiency on beef cattle production by decreasing the CH4/ADG and MJ CH4/MJ metabolizable energy intake. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/25202-5 - Efeito da dieta e da espécie forrageira no perfil metabólico em ruminantes
• Beneficiário: Rondineli Pavezzi Barbero
• Linha de fomento: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 12/20264-0 - Impactos produtivos, ambientais e econômicos de estratégias de suplementação da dieta de bovinos de corte sob alturas de pastejo e estratégias de terminação
• Beneficiário: Ricardo Andrade Reis
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/00060-8 - Balanço de gases de efeito estufa e estratégias de mitigação em pastos de Brachiaria submetidos a diferentes manejos
• Beneficiário: Telma Teresinha Berchielli
• Linha de fomento: Auxílio à Pesquisa - Temático
• Processo FAPESP: 12/14956-6 - Impactos produtivos, ambientais e econômicos de estratégias de suplementação da dieta de bovinos de corte sob alturas de pastejo e estratégias de terminação
• Beneficiário: Rondineli Pavezzi Barbero
• Linha de fomento: Bolsas no Brasil - Doutorado