Association of ingestive behavior and enteric methane emission in cattle of the Nellore breed

Abstract

The methane gas (CH4, g/day) from ruminal fermentation and eliminated during the eructation, respiration process and animal waste, is related to food consumption and digestion, with higher CH4 emission. One alternative way to reduce CH4 emissions might be select more efficient reproducers to use food in order to reduce gas emissions per unit of body weight. Intake behavior is a phenotype that cannot be used independently, but provides some understandings of the variation of the animal's dry matter consumption. The aim of this project is to explore the association of food efficiency with ingestive behavior and methane emission of bulls Nellore in order to understand the new phenotypes used in the selection process. A food efficiency test of 120 Nellore bulls with an average age of 18 months (550 days), divided into four stalls (30 animals per stall) from private properties participating in a selection program, will be performed. The performance, food efficiency and ingestive behavior variables will be obtained through the electronic monitoring system of the automatic hods of the company Intergado® (Intergado Ltda., Contagem, Minas Gerais, Brazil). The estimated methane emission (CH4, g/day) shall be obtained using the Sulphur hexafluoride (SF6) tracer gas methodology in the final period of the food efficiency test. The Pearson correlations between the characteristics will be calculated by the PROC CORR procedure of the statistical package Statistical Analysis System® (SAS Institute, Cary, NC, USA, 2011). Statistical significance shall be declared when p<0.05.