Assessing enteric methane emissions from Nellore and Angus-Nellore crossbred cattle in a tropical, intensive beef cattle production system.

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.

Bibliographic Details

Main Authors:	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.
Other Authors:	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.
Format:	Anais e Proceedings de eventos biblioteca
Language:	English eng
Published:	2020-04-14
Subjects:	Sistema intensivo de produção, Intensificação sustentável, Gado de Corte, Metano, Bovino, Efeito Estufa, Ruminante, Gás,
Online Access:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/1121629
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