Fecha/hora: 15/06/2024 17:59:25

Biblioteca(s): 	INIA Treinta y Tres.	
Fecha corriente: 	25/11/2015	
Fecha de la última actualización: 	11/10/2019	
Autoria: 	HERD, R.M.; VELAZCO, J.I.; ARTHUR, P. F.; HEGARTY, R. S.	
Afiliación: 	NSW Department of Primary Industries, Beef Industry Centre, Australia; JOSÉ IGNACIO VELAZCO DE LOS REYES, INIA (Instituto Nacional de Investigación Agropecuaria), Uruguay; Environmental and Rural Science, University of New England, Australia.; NSW Department of Primary Industries, Agricultural Institute, Australia.; Environmental and Rural Science, University of New England, Australia.	
Título: 	Proxies to adjust methane production rate of beef cattle when the quantity of feed consumed is unknown.	
Año de publicación: 	2016	
Fuente/Imprenta: 	Animal Production Science, 2016, 56, p. 231-237.	
DOI: 	10.1071/AN15477	
Idioma: 	Inglés	
Notas: 	Article history: Received 24 August 2015, accepted 11 November 2015, published online 9 February 2016.
http://dx.doi.org/10.1071/AN15477	
Contenido: 	Abstract:
The aim of this experiment was to evaluate the utility of CO2 production rate (CPR; g CO2/d) and animal weight (WT) data as proxies for feed-intake to adjust methane production rate (MPR; g CH4/d) in situations where dry-matter intake (DMI) is not known. This experiment measured individual-animal DMI, MPR and CPR in the feedlot, and then again on restricted quantities of grain and roughage diets in open-circuit respiration chambers. Of the 59 cattle tested in the feedlot, 41 had MPR and CPR recorded, and 59 and 57 had test results on the restricted grain and roughage rations. Methane production relative to DMI by individual animals was calculated as methane yield (MY; MPR/ DMI) and as residual methane production (RMPDMI; calculated as MPR less predicted MPR based on DMI). A second form of residual methane production: RMPCO2, was calculated by regressing MPR against CPR to determine whether animals were producing more or less CH4 than predicted for their CPR. Carbon-dioxide production rate was positively associated with DMI in all 3 test phases (R2=0.25, 0.45 and 0.47; all P<0.001). The associations for MY with MPR:CPR were moderate and positive: R2=0.49 in the feedlot test; R2=0.37 in the restricted grain test; and R2=0.59 in the restricted roughage test, and with RMPCO2 R-square were 0.57, 0.34 and 0.59 in the 3 test phases (all P<0.001). The R-square for RMPDMI with MPR:CPR in all 3 tests were 0.50, 0.79 and 0.69, and with RMPCO2 R-square were 0.68, 0.79 and 0.68 (all P<0.001). The high R-square for MY with MPR:CPR and RMPCO2 and even higher R-square for RMPDMI with MPR:CPR and RMPCO2 in all 3 test phases showed that CPR can be used to adjust MPR data for DMI when DMI is not recorded. In the feedlot test, where animal WT data was recorded over 70 days, MPR adjusted for WT and WT gain had R-square with MY and RMPDMI of 0.60 and 0.83 respectively (P<0.001) offering the possibility that animal WT data determined over an extended time period could also be used as a proxy for DMI in adjustment of MPR.	
Palabras-Clave: 	GANADO VACUNO; GAS METANO; GASES EFECTO INVERNADERO; GEM; GREENHOUSE GAS; RESPIRATION CHAMBER.	
Categoría del tema: 	P01 Conservación de la naturaleza y recursos de La tierra	
Registro original: 	INIA Treinta y Tres (TT)	
Ejemplares: 	TT - (101081-1) - PXI - AP - DD - PP/ANIMAL-PROD-SCIENCE/2016/VELAZCO -  -  - DIS