Using highly nutritious pastures to mitigate enteric methane emissions from cattle grazing systems in South America

Abstract

Enteric methane (CH4) emissions are directly related to the quantity and type of feed intake. Existing mitigation strategies, for example, the addition of legumes to grass-based diets and increased use of grains, have been thoroughly researched and applied in different production systems. In this paper, we propose a need to expand the capacity to mitigate enteric CH4 emissions in cattle under grazing conditions. The objective of this paper was to contribute to evaluate a mitigation strategy under grazing conditions of using contrasting levels of pasture quality. The study was performed with 20 heifers twice during the year: winter and spring. Each season, the study employed a crossover design with two treatments and two 5-day measurement periods. The treatments were two pastures with different nutritional values, including a pasture with a low quality (70% of neutral detergent fibre, 1% of ether extract, 8% of non-fibre carbohydrates), 9% of crude protein, 35% of dry matter digestibility and a pasture with a high quality (42% neutral detergent fibre, 1.3% ether extract, 24% non-fibre carbohydrates, 21% crude protein and 63% dry matter digestibility). Enteric CH4 emissions were measured with sulfur hexafluoride tracer technique. The dry matter intake (kg/day) was measured indirectly using titanium dioxide as an external marker. CH4 emissions from animals grazing the high-quality pasture were 14% lower expressed as % of gross energy intake, and 11% lower expressed by unit of dry matter intake (g CH4/kg). These results quantitative showed the alternative to mitigate CH4 emissions from grazing bovines exclusively through the improvement of the forage quality offered.

Association between residual feed intake and enteric methane emissions in Hereford steers

“…Daily permeation rates (PRs) of SF 6 from the tubes averaged (mean ± SEM) 6.0 ± 0.55 and 5.9 ± 0.58 mg/d in the LRFI and HRFI groups, respectively. The emission of enteric CH 4 was measured for the 18 animals during two consecutive 5-d periods following the procedure performed by Dini et al (2017) . The first 8 d of the study were used for the adaptation of the animals to the use of the CH 4 collection containers and for the stabilization of rumen SF 6 levels.…”

Effect of Suckling Management and Ewe Concentrate Level on Methane-Related Carbon Footprint of Lamb Meat in Sardinian Dairy Sheep Farming

“…In fact, several studies conducted on beef cattle [ 53 ] and sheep [ 54 ] farmed in grazing systems with different pasture quality evidenced that high-quality grass can reduce CH 4 emissions per unit of DMI (CH 4 /kg DMI) in comparison with low-quality grass. The positive effect of high-quality pasture on the reduction of enteric CH 4 emissions is due to the lower content of NDF, to the high content of CP, and to the higher digestibility [ 55 ]. The quantity of fresh forages offered can also have an effect: in fact, CF is lower in high, rather than in low, productive grazing systems [ 9 ].…”

Identification of N-Oxide-Containing Aromatic Heterocycles as Pharmacophores for Rumen Fermentation Modifiers

“…Consequently, many studies have been conducted to increase feed efficiency through the manipulation of rumen fermentation. In this sense, we previously observed [39,40] that gas emissions from grazing animals could be reduced by up to 14% by improving pasture quality. The herein studied compounds could be used as an alternative strategy and could be combined with high-quality pastures to reduce these emissions.…”