Phenolic plant extracts are additive in their effects against in vitro ruminal methane and ammonia formation

Abstract

Objective The methane mitigating potential of various plant-based polyphenol sources is known, but effects of combinations have rarely been tested. The aim of the present study was to determine whether binary and 3-way combinations of such phenol sources affect ruminal fermentation less, similar or more intensively than separate applications. Methods The extracts used were from Acacia mearnsii bark (acacia), Vitis vinifera (grape) seed, Camellia sinensis leaves (green tea), Uncaria gambir leaves (gambier), Vaccinium macrocarpon berries (cranberry), Fagopyrum esculentum seed (buckwheat), and Ginkgo biloba leaves (ginkgo). All extracts were tested using the Hohenheim gas test. This was done alone at 5% of dry matter (DM). Acacia was also combined with all other single extracts at 5% of DM each, and with two other phenol sources (all possible combinations) at 2.5%+2.5% of DM. Results Methane formation was reduced by 7% to 9% by acacia, grape seed and green tea and, in addition, by most extract combinations with acacia. Grape seed and green tea alone and in combination with acacia also reduced methane proportion of total gas to the same degree. The extracts of buckwheat and gingko were poor in phenols and promoted ruminal fermentation. All treatments except green tea alone lowered ammonia concentration by up to 23%, and the binary combinations were more effective as acacia alone. With three extracts, linear effects were found with total gas and methane formation, while with ammonia and other traits linear effects were rare. Conclusion The study identified methane and ammonia mitigating potential of various phenolic plant extracts and showed a number of additive and some non-linear effects of combinations of extracts. Further studies, especially in live animals, should concentrate on combinations of extracts from grape seed, green tea leaves Land acacia bark and determine the ideal dosages of such combinations for the purpose of methane mitigation.

Mature herbs as supplements to ruminant diets: effects on in vitro ruminal fermentation and ammonia production

“…It is expected that tannins will protect dietary proteins from ruminal degradation by the formation of complexes (Perez-Maldonado et al 1995), which could reduce the generation of ammonia and improve protein efficiency of dairy cows. There is in vitro (Jayanegara et al 2011;Sinz et al 2019b) and in vivo evidence (Kälber et al 2012;Sinz et al 2019a) that tannin-rich forage herbs may have this effect. It is important to identify forage combinations that simultaneously lower ruminal ammonia concentration and maintain fermentation efficiency, including microbial protein synthesis (Jayanegara et al 2013;Sinz et al 2019b).…”

The effects of dietary supplementation with 3-nitrooxypropanol on enteric methane emissions, rumen fermentation, and production performance in ruminants: a meta-analysis

“…This is because CH 4 is a substantial anthropogenic greenhouse gas, possessing a global warming potential 28-34 times greater than carbon dioxide (CO 2 ) [1], and makes up 2%-12% of the loss of dietary gross energy (GE) intake to the ruminants [2]. Thus, there have been numerous global efforts to mitigate ruminal CH 4 emissions, using various feed additives such as tannin [3,4], dietary fats containing polyunsaturated fatty acids [5], plant essential oils [6,7], and phytochemicals [8,9].…”

Combination Effects of Plant Extracts Rich in Tannins and Saponins as Feed Additives for Mitigating in Vitro Ruminal Methane and Ammonia Formation

“…Similarly, a methanolic extract of the Saponaria officinalis root (containing saponins) reduced methanogenesis by about 30% and lowered protozoa and methanogen counts without causing adverse effects on rumen fermentation and in vitro dry matter digestibility [ 17 ]. Both tannins [ 18 , 19 ] and saponins [ 11 , 20 ] have also been shown to decelerate ruminal protein degradation and, therefore, prevent the formation of (excessive) ammonia, although their mode of action differs. Tannins bind to proteins at a ruminal pH, thus preventing access by microbes.…”