Impact of pasture type on methane production by lactating beef cows

The effects of feeding total mixed ration (TMR) or pasture forage from a perennial sward under a management intensive grazing (MIG) regimen on grain intake and enteric methane (EM) emission were measured using chambers. Chamber measurement of EM was compared with that of SF 6 employed both within chamber and when cows grazed in the field. The impacts of the diet on farm gate greenhouse gas (GHG) emission were also postulated using the results of existing life cycle assessments. Emission of EM was measured in gas collection chambers in Spring and Fall. In Spring, pasture forage fiber quality was higher than that of the silage used in the TMR (47.5% v. 56.3% NDF; 24.3% v. 37.9% ADF). Higher forage quality from MIG subsequently resulted in 25% less grain use relative to TMR (0.24 v. 0.32 kg dry matter/kg milk) for MIG compared with TMR. The Fall forage fiber quality was still better, but the higher quality of MIG pasture was not as pronounced as that in Spring. Neither yield of fat-corrected milk (FCM) which averaged 28.3 kg/day, nor EM emission which averaged 18.9 g/kg dry matter intake (DMI) were significantly affected by diet in Spring. However, in the Fall, FCM from MIG (21.3 kg/day) was significantly lower than that from TMR (23.4 kg/day). Despite the differences in FCM yield, in terms of EM emission that averaged 21.9 g/kg DMI was not significantly different between the diets. In this study, grain requirement, but not EM, was a distinguishing feature of pasture and confinement systems. Considering the increased predicted GHG emissions arising from the production and use of grain needed to boost milk yield in confinement systems, EM intensity alone is a poor predictor of the potential impact of a dairy system on climate forcing.

Section: Diet Qualitysupporting

confidence: 83%

Implications of dairy systems on enteric methane and postulated effects on total greenhouse gas emission

Fredeen

Juurlink²,

Main

et al. 2013

“…No change in CH 4 emission has been found with other legumes (see Van Dorland et al, 2007;Hammond et al, 2011) with clover, and in the metaanalysis by Archimède et al (2011), comparing grasses and legumes. A decrease in enteric CH 4 production with high amounts of lucerne was expected based on literature data such as McCaughey et al (1999), who showed that the partial replacement of grasses with lucerne for grazing beef cows decreased CH 4 production per kg DM by 22%. These authors suggested that the lower CH 4 production with lucerne in their trial might have been because of a higher ruminal passage rate with lucerne than with grasses; an increase in ruminal passage rate decreases CH 4 enteric production.…”

Section: Doreau Ferlay Rochette and Martinmentioning

confidence: 86%

“…It has been suggested that feeding lucerne could reduce CH 4 emissions compared with grass. Although no specific effect of legumes was evidenced in a recent meta-analysis on temperate forages (Archimède et al, 2011), a mitigating effect of lucerne on pasture was shown by McCaughey et al (1999) when lucerne partially replaced grasses. The use of lucerne may also lower nitrous oxide emissions through the absence of N fertilisation (Rochette and Janzen, 2005).…”

Section: Introductionmentioning

confidence: 96%

Effects of dehydrated lucerne and soya bean meal on milk production and composition, nutrient digestion, and methane and nitrogen losses in dairy cows receiving two different forages

Doreau

Ferlay

Rochette

et al. 2014

Dehydrated lucerne is used as a protein source in dairy cow rations, but little is known about the effects of lucerne on greenhouse gas production by animals. Eight Holstein dairy cows (average weight: 582 kg) were used in a replicated 4 × 4 Latin square design. They received diets based on either maize silage (M) or grass silage (G) (45% of diet on dry matter (DM) basis), with either soya bean meal (15% of diet DM) completed with beet pulp (15% of diet DM) (SP) or dehydrated lucerne (L) (30% of diet DM) as protein sources; MSP, ML, GSP and GL diets were calculated to meet energy requirements for milk production by dairy cows and degradable protein for rumen microbes. Dry matter intake (DMI) did not differ among diets (18.0 kg/day DMI); milk production was higher with SP diets than with L diets (26.0 v. 24.1 kg/day), but milk production did not vary with forage type. Milk fatty-acid (FA) composition was modified by both forage and protein sources: L and G diets resulted in less saturated FA, less linoleic acid, more trans-monounsaturated FA, and more linolenic acid than SP and M diets, respectively. Enteric methane (CH 4 ) production, measured by the SF 6 tracer method, was higher for G diets than for M diets, but did not differ with protein source. The same effects were observed when CH 4 was expressed per kg milk. Minor effects of diets on rumen fermentation pattern were observed. Manure CH 4 emissions estimated from faecal organic matter were negatively related to diet digestibility and were thus higher for L than SP diets, and higher for M than G diets; the resulting difference in total CH 4 production was small. Owing to diet formulation constraints, N intake was higher for SP than for L diets; interaction between forage type and protein source was significant for N intake. The same statistical effects were found for N in milk. Faecal and urinary N losses were determined from total faeces and urine collection. Faecal N output was lower for M than for G diets but did not differ between protein sources. Urinary N output did not differ between forage types, but was lower for cows fed L diets than for cows fed SP diets, potentially resulting in lower ammonia emissions with L diets. Replacing soya bean meal plus beet pulp with dehydrated lucerne did not change CH 4 production, but resulted in more N in faeces and less N in urine.

“…According to the prediction model of Benchaar et al (2001), the substitution of timothy hay by lucerne decreases CH 4 emissions by 21% (expressed as % of digestible energy). In a direct comparison, McCaughey et al (1999) observed on grazing beef cattle a 10% decrease in CH 4 production by unit of product when grasses were replaced by a mixture of lucerne and grasses (70 : 30). The authors concluded that this was due to the higher intake observed for lucerne-fed animals, which was related with a higher digestibility rate and an increased passage of feed particles out of the rumen.…”

Section: Mitigation Through Feedingmentioning

confidence: 99%

Methane mitigation in ruminants: from microbe to the farm scale

Martin

Morgavi

Doreau

2010

747

657

Decreasing enteric methane (CH 4 ) emissions from ruminants without altering animal production is desirable both as a strategy to reduce global greenhouse gas (GHG) emissions and as a means of improving feed conversion efficiency. The aim of this paper is to provide an update on a selection of proved and potential strategies to mitigate enteric CH 4 production by ruminants. Various biotechnologies are currently being explored with mixed results. Approaches to control methanogens through vaccination or the use of bacteriocins highlight the difficulty to modulate the rumen microbial ecosystem durably. The use of probiotics, i.e. acetogens and live yeasts, remains a potentially interesting approach, but results have been either unsatisfactory, not conclusive, or have yet to be confirmed in vivo. Elimination of the rumen protozoa to mitigate methanogenesis is promising, but this option should be carefully evaluated in terms of livestock performances. In addition, on-farm defaunation techniques are not available up to now. Several feed additives such as ionophores, organic acids and plant extracts have also been assayed. The potential use of plant extracts to reduce CH 4 is receiving a renewed interest as they are seen as a natural alternative to chemical additives and are well perceived by consumers. The response to tannin-and saponincontaining plant extracts is highly variable and more research is needed to assess the effectiveness and eventual presence of undesirable residues in animal products. Nutritional strategies to mitigate CH 4 emissions from ruminants are, without doubt, the most developed and ready to be applied in the field. Approaches presented in this paper involve interventions on the nature and amount of energy-based concentrates and forages, which constitute the main component of diets as well as the use of lipid supplements. The possible selection of animals based on low CH 4 production and more likely on their high efficiency of digestive processes is also addressed. Whatever the approach proposed, however, before practical solutions are applied in the field, the sustainability of CH 4 suppressing strategies is an important issue that has to be considered. The evaluation of different strategies, in terms of total GHG emissions for a given production system, is discussed.Keywords: methane, greenhouse gases, ruminant, mitigation strategies Implications Methane (CH 4 ) mitigation in ruminants is possible through various strategies. Today, the feeding management approach is the most developed. Other strategies (biotechnologies, additives) are promising but the diversity and plasticity of functions of the rumen bacterial and methanogenic communities may be a limiting factor for their successful application. A possible selection of animals on CH 4 production and more likely on digestive processes is evocated. In any case, before practical solutions are proposed for field application more research in vivo is needed. The sustainability of CH 4 -suppressing strategies is also an important issue and they mi...