Título:	Assessing enteric methane emissions from Nellore and Angus-Nellore crossbred cattle in a tropical, intensive beef cattle production system.
Autor:	MACIEL, I. C. F. BARBOSA, F. A. TOMICH, T. R. ALVARENGA, R. C. FERREIRA, L. R. ROWNTREE, J. THOMPSON, L. R. LANA, A. M. Q.
Afiliación:	Isabella Cristina F. Maciel, Michigan State University; Fabiano A. Barbosa, De Heus Animal Nutrition B.V; THIERRY RIBEIRO TOMICH, CNPGL; RAMON COSTA ALVARENGA, CNPMS; Ludhiana R. Ferreira, Universidade Federal de Minas Gerais; Jason Rowntree, Michigan State University; Logan R. Thompson, Michigan State University; Ângela Maria Q. Lana, Universidade Federal de Minas Gerais.
Año:	2019
Referencia:	In: ANNUAL MEETING AND TRADE SHOW, 2019, Worcester. Abstracts... Worcester: [s.n.], 2019.
Descripción:	Crossbreeding has been used to improve performance in beef cattle; however, the effects of breed composition on methane production, yield and intensity from cattle in a tropical intensive system remain unknown. To assess the impact of breed composition on enteric methane emissions, Nellore (NE; yr 1: BW = 171.5 ± 19.4 kg; n = 10; yr 2: BW = 215.8 ± 32.3 kg, n = 25) and Angus-Nellore crossbred (AN; yr 1: BW = 214.2 ± 26.4 kg, n = 10; yr 2: BW = 242.5 ± 32.2 kg, n = 25) were compared. At trial onset, 10 mo old steers grazed Megathyrsus maximus ?Mombaça? in the grazing period (GP) and then were finished in a feedlot (FL) (35:65% corn silage:concentrate diet). Steers (n = 8) from each breed composition were randomly selected in GP and FL to measure CH4 production using a sulfur hexafluoride technique and DMI using titanium dioxide. The NE produced 19% less CH4 than AN in GP (17.21 vs 21.17 kg, P < 0.01), and no difference was observed in FL (22.34 vs 22.67 kg, P > 0.10). However, in FL, NE had greater CH4 intensity (CH4/ADG) compared to AN (122.76 vs 97.49 g/kg, P < 0.01). Furthermore, CH4/carcass weight was greater for NE than AN (0.079 vs 0.067 g/kg CW, P < 0.01). Breed composition did not influence CH4 yield (CH4/DMI) in either phase. The percentage CH4/GEI (Ym) for GP was higher for AN than NE (4.5 vs 3.8%), but lower than the IPCC recommended Ym of 6.5%. In FL, Ym was similar between breed composition (5.0%) and greater than the IPCC Ym of 3%. In our study the introduction of Angus into Nellore has potential to reduce CH4 intensity in tropical climates, resulting in less methane emission per kg beef produced.
Thesagro:	Gado de Corte Metano Bovino Efeito Estufa Ruminante Gás
Palabras clave:	Sistema intensivo de produção Intensificação sustentável
DOI:	10.1093/jas/skz258.757
Notas:	Publicado no Journal of Animal Science, v. 97, p. 380-381, 2019. Suppl. 3.
Tipo de Material:	Resumo em anais e proceedings
Acceso:	openAccess
Aparece en las colecciones:	Resumo em anais de congresso (CNPMS)