Abstract

Methane production was measured in 301, 3-year-old Friesian x Jersey dairy cows, during summer 2004 in stage one of a project to define phenotypes for quantitative trait loci (QTL) mapping and to investigate the relationships between CH4 and milk production. Animals were allocated into four groups and their methane production was measured during four days. Feed intake was estimated by the alkane technique and by prediction equations. Correlations between the alkane technique and prediction equations were all less than 0.37, but correlations amongst the prediction equations were greater than 0.61. Daily CH4 output varied from 210 to 498 g and averaged 332 g. Dry matter intake averaged 19.3 g/kg DM. Milk production and live weight gain were negatively related to CH4 production per kg dry matter intake. Sire was not found to have a significant effect on CH4 output per kg of dry matter; however, only six sires are represented in the trial. The CH4 output recorded in the current study was within the ranges observed in other studies and was repeatable between days. High quality data were generated for the QTL study. KEYWORDS: methane; herbage intake; alkanes; dairy cows.

LR, McNaughton, DP Berry, H Clark, C PinaresPatino, S Harcourt, and RJ Spelman

Proceedings of the New Zealand Society of Animal Production, Volume 65, Christchurch, 352-355, 2005