Data/hora: 21/06/2024 03:31:32

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	14/02/2017	
Data da última atualização: 	30/01/2023	
Autoria: 	OSS, D. B.; MARCONDES, M. I.; MACHADO, F. S.; PEREIRA, L. G. R.; TOMICH, T. R.; RIBEIRO JR. G. O.; CHIZZOTTI, M. L.; FERREIRA, A. L.; CAMPOS, M. M.; MAURÍCIO, R. M.; CHAVES, A. V.; McALLISTER, T. A.	
Afiliação: 	Daniela B. Oss, UFV; CAPES; Marcos I. Marcondes, UFV; FERNANDA SAMARINI MACHADO, CNPGL; LUIZ GUSTAVO RIBEIRO PEREIRA, CNPGL; THIERRY RIBEIRO TOMICH, CNPGL; Gabriel O. Ribeiro Jr., CAPES; , Agriculture and Agri-Food Canada; Mario Luiz Chizzotti, UFV; Alexandre L. Ferreira, UFSJ; MARIANA MAGALHAES CAMPOS, CNPGL; Rogério M. Maurício, UFSJ; Alex V. Chaves, Faculty of Veterinary Science, Sydney; Tim A. McAllister, Agriculture and Agri-Food Canada.	
Título: 	An evaluation of the face mask system based on short-term measurements compared with the sulfur hexafluoride (SF6) tracer, and respiration chamber techniques for measuring CH4 emissions.	
Ano de publicação: 	2016	
Fonte/Imprenta: 	Animal Feed Science and Technology, v. 216, p. 49-57, 2016.	
Idioma: 	Inglês	
Conteúdo: 	The objective of the present study was to compare the shortterm measurement(30 min/day for 3 days) face mask system (FM), with SF6 tracer and respiration chamber (RC) techniques for measuring CH4 emissions from crossbred (Holstein × Gyr) yearling bulls fed at three intake levels. Data were derived from 17 individuals in a completely randomized design experiment in a repeated measures scheme. Bulls were fed a diet consisting of 59.6% corn silage and 40.4% concentrate on a DM basis at three levels of DM intake (DMI) of 1.2% of BW, 1.8% of BW and ad libitum. After an adaptation period, CH4 emissions were measured first using the SF6 tracer technique, followed by the FM and RC techniques, respectively. Daily CH4 emission (g/day) from bulls differed (P < 0.007) with CH4 measurements techniques, with highest emissions measured using RC (107.9 ± 15.36), followed by FM (103.2 ± 11.86) then SF6 tracer technique (87.9 ± 10.16). The CH4 emissions adjusted for differences in DMI and BW did not differ among techniques, averaging 21.5 g/kg DMI and 0.4 g/kg BW, respectively. Total CH4 emissions (g/day) were positively correlated with DMI as measured by all three techniques (SF6 r = 0.93; FM r = 0.93; RC r = 0.96). The concordance correlation coefficient (CCC) for CH4 emission (g/d) were 0.82, 0.82 and 0.74 for comparisons of SF6 vs RC, FM vs RC and FM vs SF6, respectively. The day-to-day (21.3%) and animal-to-animal (13.4%) variation in CH4 yield (g/kg DMI) was greater from bulls using the FM technique, compared to SF6 (18.8% and 6.8%, respectively) and RC (12.9% and 7.5%, respectively) techniques. We conclude that the short-term FM technique generated CH4 measurements that were comparable to those estimated using SF6 and chamber techniques across a range of DMI levels. However, the FM method may have limitations in terms of assessing enteric CH4 mitigation strategies that are applied over a short duration to low numbers of animals due to higher animal-to-animal and day-to-day coefficients of variation than either the SF6 or RC techniques.	
Palavras-Chave: 	Face mask; Respiration chamber; Short-term measurement.	
Thesaurus Nal: 	methane; sulfur hexafluoride.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (23291-1) - UPC - AP - DD -  -  -  - DIS