Fecha/hora: 12/06/2024 14:50:15

Biblioteca(s): 	INIA La Estanzuela.	
Fecha corriente: 	08/11/2018	
Fecha de la última actualización: 	13/02/2020	
Autoria: 	DINI, Y.; CAJARVILLE, C.; GERE, J.I.; FERNANDEZ. S.; FRAGA, M.; PRAVIA, M.I.; NAVAJAS, E.; CIGANDA, V.	
Afiliación: 	YOANA DINI, Departamento de Nutrición Animal, Facultad de Veterinaria, Universidad de la República,  San José, Uruguay.; CECILIA CAJARVILLE, Departamento de Nutrición Animal, Facultad de Veterinaria, Universidad de la República,  San José, Uruguay.; J I GERE, UIDI, Facultad Regional Buenos Aires, Universidad Tecnológica Nacional. Ciudad Autónoma de Buenos Aires, Argentina.; S FERNANDEZ, Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.; MARTIN FRAGA COTELO, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; MARIA ISABEL PRAVIA NIN, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; ELLY ANA NAVAJAS VALENTINI, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; VERONICA SOLANGE CIGANDA BRASCA, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay.	
Título: 	Association between residual feed intake and enteric methane emissions in Hereford steers.	
Año de publicación: 	2019	
Fuente/Imprenta: 	Translational Animal Science, v. 3, Issue 1, 1 January 2019, Pages 65-72. Doi: https://doi.10.1093/tas/txy111.	
DOI: 	10.1093/tas/txy111	
Idioma: 	Inglés	
Notas: 	Article history: Published: 01 October 2018 // Received: 12 September 2018.	
Contenido: 	Abstract:
The objective of this study was to quantify the emissions of enteric CH4 from growing Hereford steers raised under feedlot conditions based on contrasting levels of residual feed intake (RFI). A repeated measurements experiment was conducted over 20 d to determine CH4 production from two groups of nine Hereford steers, with contrasting RFI values (mean ± SD): low RFI (LRFI group; &#8722;0.78 ± 0.22 kg DMI/d) vs. high RFI (HRFI group; 0.83 ± 0.34 kg DMI/d). Steers were selected from a larger contemporary population in which the RFI was evaluated. Steers were maintained under confined conditions with ad libitum access to water and feed, comprising a total mixed ration of 55% sorghum silage, 21% barley silage, 21% corn grain, and 3% protein?mineral?vitamin?premix, provided twice a day. Before the beginning of CH4 measurements, the live weight of both groups of animals was determined, which on average (±SEM) was 357.0 ± 5.11 and 334.0 ± 10.17 kg in the LRFI and HRFI groups, respectively. Methane emission (g/d) was measured on each animal with the sulfur hexafluoride (SF6) tracer technique, during two consecutive periods of 5 d. Individual daily intake and feeding behavior characteristics were measured using a GrowSafe automated feeding system (Model 6000, GrowSafe Systems Ltd, Airdrie, Alberta, Canada). Methanogens in the ruminal content were quantified using quantitative polymerase chain reaction with primers targeting the mcrA gene. Methane emission was near 27% lower in animals with LRFI when expressed in absolute terms (g/d; 26.8%; P = 0.009), by unit of dry matter intake (g CH4/kg; 27.9%, P = 0.021), or as % of gross energy intake (26.7%; P = 0.027). These differences could not be explained by differences in amount of total of methanogens (average = 9.82 log10 units; P = 0.857). However, there were some differences in animal feeding behavior that could explain these differences (e.g., LRFI animals tended to spend less time in feeders). Our results suggest that, in Hereford steers, the selection by RFI values is a promising mitigation strategy for the reduction of the emission of enteric CH4.	
Palabras-Clave: 	ENTERIC METHANE; FEEDING BEHAVIOUR; METHANOGENS; RESIDUAL FEED INTAKE; STEERS.	
Thesagro: 	GASES DE EFECTO INVERNADERO; HEREFORD; NOVILLOS.	
Categoría del tema: 	--	
Registro original: 	INIA La Estanzuela (LE)	
Ejemplares: 	LE - (102622-1) - PXI - AP - DD - PP/Translational Animal Science/2019 -  -  - DIS