How precise are enteric methane emission phenotypes or breeding values estimated from spot flux measures?

Abstract

This study was conducted to determine the precision or confidence interval of phenotypes and estimated breeding values for enteric methane (CH₄) emissions of individual animals estimated from spot measurements of methane flux. Components of variance of daily methane production (DMP; gCH₄/d) and methane yield (MY; gCH₄/kg DMI) from trial data were used to estimate the precision for assumed heritability values. The precision was relatively insensitive to number of measures per animal per day and to the number of days of measurement. The values of the residual components of variance (between measures, within-animals, within-days) are high compared to between animal and between day variance but the confidence intervals for EBVs for DMP and MY estimated from spot flux measures are about 20% each side of the mean, which should be adequate for industry implementation in breeding schemes.