Are dietary strategies to mitigate enteric methane emission equally effective across dairy cattle, beef cattle, and sheep?

Abstract

The digestive physiology of ruminants is sufficiently different (e.g., with respect to mean retention time of digesta, digestibility of the feed offered, digestion, and fermentation characteristics) that caution is needed before extrapolating results from one type of ruminant to another. The objectives of the present study were (1) to provide an overview of some essential differences in rumen physiology between dairy cattle, beef cattle, and sheep that are related to methane (CH 4 ) emission; and (2) to evaluate whether dietary strategies to mitigate CH 4 emission with various modes of action are equally effective in dairy cattle, beef cattle, and sheep. A literature search was performed using Web of Science and Scopus, and 94 studies were selected from the literature. Per study, the effect size of the dietary strategies was expressed as a proportion (%) of the control level of CH 4 emission, as this enabled a comparison across ruminant types. Evaluation of the literature indicated that the effectiveness of forage-related CH 4 mitigation strategies, including feeding more highly digestible grass (herbage or silage) or replacing different forage types with corn silage, differs across ruminant types. These strategies are most effective for dairy cattle, are effective for beef cattle to a certain extent, but seem to have minor or no effects in sheep. In general, the effectiveness of other dietary mitigation strategies, including increased concentrate feeding and feed additives (e.g., nitrate), appeared to be similar for dairy cattle, beef cattle, and sheep. We concluded that if the mode of action of a dietary CH 4 mitigation strategy is related to ruminant-specific factors, such as feed intake or rumen physiology, the effectiveness of the strategy differs across ruminant types, whereas if the mode of action is associated with methanogenesis-related fermentation pathways, the strategy is effective across ruminant types. Hence, caution is needed when translating ef-fectiveness of dietary CH 4 mitigation strategies across different ruminant types or production systems.

Incorporating a Fresh Mixed Annual Ryegrass and Berseem Clover Forage Into the Winter Diet of Dairy Cows Resulted in Reduced Milk Yield, but Reduced Nitrogen Excretion and Reduced Methane Yield

“…The greater CP and lower NDF concentrations of the CON diet were expected to shift fermentation toward propionate production ( 45 ), thus reducing substrate availability for methanogenic bacterial activity and methane production. In contrast, the slightly greater DM digestibility of the MIX diet could have induced higher feed intake, thereby increasing passage rate and reduce methane production for MIX cows ( 46 ). This must have made up for the numerically lower methane yield and methane intensities from MIX cows than the CON cows.…”

Enteric methane emission of the Dutch dairy herd : Average and variation of enteric methane emission among the Dutch dairy herd

“…For the Dutch dairy sector maximum reduction potentials by feeding strategies are estimated up to 37% compared to 1990, approximately 5% was already achieved in 2013 (Sebek et al, 2014). A recent literature review by Van Gastelen et al (2019b) gives an overview of 94 studies of dietary strategies to mitigate enteric CH4 in either dairy cattle, beef cattle or sheep.…”

Lamb Fattening Under Intensive Pasture-Based Systems: A Review

“…Nevertheless, the same levels of supplementation in sheep resulted in excessive ruminal fermentation that reduced fiber digestibility and intake. In the same way, van Gastelen et al [11] highlighted the caution needed before extrapolating results of CH 4 mitigation, mainly due to differences between dairy cattle, beef cattle, and sheep.…”

“…Although sheep have been used as an experimental rumen model for feed evaluation and feeding studies, the information on diets specifically designed for sheep is not as abundant as that for other ruminants (dairy and beef cattle), which may be because of the variety of conditions in which sheep are raised. However, the digestive physiology of sheep is quite different from cattle; mainly associated with differences in digesta retention times, rumen digestion, and fermentation characteristics [11][12][13], so the use of feeding strategies designed for beef or dairy cattle is not recommended for sheep nutrition. For example, Aguerre et al [13] observed in animals consuming lotus (Lotus corniculatus), that increasing supplementation with sorghum grain from 1% to 1.5% of body weight (BW) was effective in increasing feed intake and digestive use in cattle.…”