Effect of pasture type (alfalfa vs. grass) on methane and carbon dioxide production by yearling beef heifers

Abstract

. 2006. Effect of pasture type (alfalfa vs. grass) on methane and carbon dioxide production by yearling beef heifers. Can. J. Anim. Sci. 86: [409][410][411][412][413][414][415][416][417][418]. The objective of this study was to determine effect of pasture type on methane and carbon dioxide production by heifers grazing alfalfa or grass pastures at three sites across western Canada. All pastures were intensively managed so that heifers had ad libitum access to new forage material each day, and pastures were back-fenced to prevent the heifers accessing previously grazed areas. As measured using the sulfur hexafluoride (SF 6 ) tracer technique, total methane production at the Brandon, MB, and Swift Current, SK, sites was unaffected by pasture type (averaging 157.4 g CH 4 head -1 d -1 ), whereas at Lethbridge, AB, heifers grazing alfalfa produced more methane than did those on the grass pasture (162.8 vs. 113.5 g CH 4 head -1 d -1 ; P < 0.05). Calculated with dry matter intake (DMI) estimated by alkane analysis, methane production per unit DMI was 39% lower from heifers consuming grass compared with alfalfa (P < 0.001). When intakes were estimated by the Cornell Net Carbohydrate and Protein System (CNCPS) model, CH 4 production kg -1 DMI did not differ (P > 0.05) between pasture types. Loss of gross energy intake (GEI) to methane, as estimated by alkane analysis, was 6.9% for heifers grazing grass, and 9.6% for heifers grazing alfalfa (P < 0.001). Calculated using CNCPS, losses were similar (P > 0.05) between grass and alfalfa (5.8 vs. 6.2% of GEI, respectively). Carbon dioxide production per unit DMI did not differ between pasture types, irrespective of method used to estimate intake (alkanes or CNCPS). The method used to predict intake can have a major influence on calculated values when methane emissions are expressed as a percentage of GEI in grazing ruminants. At each site, CH 4 emissions and in vitro digestibility of the forage were influenced by the composition of the stand and the maturity of the forage at the time of harvest.

Evaluation of feeds from tropical origin for in vitro methane production potential and rumen fermentation in vitro

“…A lower methane production expressed as mL/g DM for red clover compared with perennial ryegrass was also noted, but methane production expressed relative to feed degradability was reversed (Navarro-Villa et al, 2011), which has been explained due to the greater degradability of ryegrass. Methane production expressed in terms of feed intake was also higher with alfalfa than with grass (Chaves et al, 2006). However in this study, methane production (per unit of DM incubated or degraded OM) potential was generally lower for cereal and grass forages than legume forages though fiber content was lower in berseem and cowpea than in grass forages, and degradability of legume forages was high.…”

Herd-scale measurements of methane emissions from cattle grazing extensive sub-tropical grasslands using the open-path laser technique

“…Boland et al (2013) using the SF 6 tracer gas technique recorded CH 4 emissions from dairy heifers grazing good quality temperate pastures of 0.35 to 0.4 g/kg BW. Similarly, Chaves et al (2006) observed values of between 0.3 and 0.45 g/kg BW for grazing heifers in the Canadian prairies, while data from the United Kingdom for perennial ryegrass indicated higher emissions of 0.59 g/kg BW (Hammond et al, 2014). Data collected under tropical conditions using the OPL range between 0.52 and 0.56 g/kg BW (McGinn et al, 2011;Tomkins et al, 2011;McGinn et al, 2015).…”

Effects of essential oils from African basil on fermentation ofAndropogon gayanusgrass in the Artificial Rumen (RUSITEC)

“…From day 8 to day 16, collected effluent was sampled at the time of feeding and processed for volatile fatty acid (VFA) and ammonia analysis as described by Wang et al (1998). Prior to gas measurement on days 8Á16, a 10-mL sample of gas was obtained from the septum of collection bags using a 26-gauge needle (Becton Dickinson, Franklin Lakes, NJ) and transferred to evacuated 6.8-mL exetainers (Labco Ltd., Wycombe, Bucks, UK) for later analysis of daily methane concentration (Chaves et al 2006;Fraser et al 2007). The 48-h feedbags removed from each fermenter were processed to determine apparent DM disappearance (DMD) from day 8 to the end of the experiment as described by Li et al (2013).…”