The Use of Temperate Tannin Containing Forage Legumes to Improve Sustainability in Forage–Livestock Production

Abstract

Greenhouse gas emissions from ruminant livestock production systems contribute significantly to the environmental footprint of agriculture. Emissions are lower for feedlot systems than for grass-based systems primarily because of the extra time required for grass-finished cattle to reach slaughter weight. In contrast, legume forages are of greater quality than grasses, which enhances intake and food conversion efficiencies, leading to improvements in production and reductions in environmental impacts compared with forage grasses. In addition, the presence of certain bioactives in legumes such as condensed tannins (CT) enhance the efficiency of energy and protein use in ruminants relative to grasses and other feeds and forages. Grazing tannin-containing legumes also reduce the incidence of bloat and improve meat quality. Synergies among nutrients and bioactives when animals graze diverse legume pastures have the potential to enhance these benefits. Thus, a diversity of legumes in feeding systems may lead to more economically, environmentally, and socially sustainable beef production than grass monocultures or feedlot rations.

Analysis and correlations of the protein content and selected ‘antinutrients’ of faba beans (Vicia faba) in a German sample set of the cultivation years 2016, 2017, and 2018

“…There it depends on the animal species (monogastric vs. ruminant animals), if certain amounts of antinutrients (even more individually for tannins) are compatible. 30,40 For example, Jansman et al reported that peas with a high tannin content reduced the protein digestibility for pig feeding and, respectively, increased the endogenous excretion of proteins, especially those that were rich in proline and histidine. 41 Tannins also showed a significant negative impact on apparent energy and protein digestibility in broiler feeding.…”

“…There it depends on the animal species (monogastric vs . ruminant animals), if certain amounts of antinutrients (even more individually for tannins) are compatible 30,40 . For example, Jansman et al .…”

Environmental impact of phytobiotic additives on greenhouse gas emission reduction, rumen fermentation manipulation, and performance in ruminants: an updated review

“…The PC/PD ratio can affect the biological activity of CTs, as demonstrated in sainfoin ( Onobrychis viciifolia ) (Hatew et al 2016 ). The degree of polymerization and cis/trans ratio also play a role in the biological activity of CTs, as shown by a negative correlation between nitrogen solubility and these factors in sainfoin (Lagrange et al 2021 ).…”

Investigating the efficacy of purified tannin extracts from underutilized temperate forages in reducing enteric methane emissions in vitro

“…Inclusion of bioactive forages, such as tannin containing forages, are deemed to be a particularly promising CH 4 mitigation strategy due to their concomitant reduction of food-feed competition, and their bene cial effects on animal health and productivity [7][8][9] . For example, the inclusion of tannin-containing forages in grasslandbased livestock production systems has the potential to reduce bloating incidences and parasitic burdens in animals 10,11 . The bene ts of tannins are derived from their molecular structure, which enables them to form stable complexes with both feed components (such as protein or ber) which can reduce the production of ammonia during ruminal fermentation and increase the fraction of rumen escape protein 12,13 .…”