Seasonal variation in methane emission from dairy cows and breeding ewes grazing ryegrass/white clover pasture in New Zealand

Abstract

Daily methane emission from 12 Romney-cross-bred ewes and 10 lactating Friesian dairy cows, rotationally grazed on perennial ryegrass/white clover dominant pastures, was measured during four seasons of a year (September, November, March, and June/July). Methane emission was measured from each animal for 5 consecutive days in each measurement period using the sulphur hexafluoride tracer gas technique. The pastures varied significantly in chemical composition between seasons, generally decreasing in protein, soluble sugars, and digestibility and increasing in acid detergent fibre (ADF) and neutral detergent fibre (NDF) as the grasses flowered in November, with an increase in protein and a decrease in soluble sugars in March, a trend that continued through to June/July. Methane emission (g/day) from dairy cows was significantly different (P < 0.001) between seasons, being high at peak A02021 ;

The SF6 tracer technique for measurements of methane emission from cattle – effect of tracer permeation rate

“…1) or 3 (exp. 2) consecutive days using the SF 6 tracer gas technique as described by Ulyatt et al (2002). Briefly, pre-calibrated permeation tubes were dosed per os into the reticulo-rumen of each animal 7 d prior to the collection of breath samples, to ensure that SF 6 concentration had reached equilibrium in the rumen.…”

Inverse modelling of European CH&lt;sub&gt;4&lt;/sub&gt; emissions during 2006–2012 using different inverse models and reassessed atmospheric observations

“…Unfortunately, only very limited information is available about potential seasonal variations of anthropogenic CH 4 sources (other than rice and biomass burning). Ulyatt et al (2010) reported significant seasonal variations of CH 4 emissions from dairy cows, mainly related to the lactation periods of cows. VanderZaag et al (2014), estimating total CH 4 emissions from two dairy farms, found higher CH 4 emissions in autumn compared to spring, mainly due to varying CH 4 emissions from manure management.…”

“…Ulyatt et al (2010) reported significant seasonal variations of CH 4 emissions from dairy cows, mainly related to the lactation periods of cows. VanderZaag et al (2014), estimating total CH 4 emissions from two dairy farms, found higher CH 4 emissions in autumn compared to spring, mainly due to varying CH 4 emissions from manure management. Besides agricultural CH 4 sources, CH 4 from landfills (Spokas et al, 2011) and waste water may also exhibit seasonal variations, while only small seasonal variations were found for natural gas distribution systems (McKain et al, 2015;Wennberg et al, 2012;Wong et al, 2016; and further references therein).…”

Estimating daily methane production in individual cattle with irregular feed intake patterns from short-term methane emission measurements

“…Typically, the arithmetic average of spot measures is used as the estimate of daily methane production (DMP; g CH 4 /day) yet the accuracy and precision of this approach has not been studied. Emission rates are known to change over momentary, diurnal and longer seasonal patterns (Ulyatt et al, 2002;Munger and Kreuzer, 2008;Crompton et al, 2011), requiring representative sampling. If the protocol does not incorporate sampling of emissions at least over the diurnal feeding and activity cycle, a scaling-up coefficient (as used by Garnsworthy et al, 2012) or adjustment factors (such as for animal activity and time spent in each activity as used by Chagunda et al, 2009) may be required to avoid bias in estimating DMP.…”