The Fate of Tannins from Birdsfoot Trefoil and Their Effect on the Nitrogen Balance in Growing Lambs Fed Diets Varying in Protein Level

Abstract

Two experimental periods were employed to investigate the fate of ingested CT from BT and their effects on the intake, digestibility, and N balance in lambs fed diets differing in CP levels. In period 1, 24 lambs were fed a basal diet either treated with polyethylene glycol (PEG+) to deactivate CT or without polyethylene glycol (PEG−). In period 2, the same lambs were used in a 2 × 2 factorial design and fed either the basal diet (BP) or a high protein diet (HP), again treated with or without PEG. In both experimental periods, feeding lambs diets without PEG caused a reduction in the dry matter (DM) intake and an increase in the DM digestibility. Urinary and total N excretion decreased in lambs fed diets without PEG, but only in absolute terms and not in relation to the N intake. The total N intake, total N excretion, and body N retention were higher with a higher dietary CP level. Related to the CT intake, less soluble and protein-bound CT were excreted by lambs fed diets without PEG, and more protein-bound and fiber-bound CT were excreted by lambs fed BP diets. Regardless of the PEG treatment and CP level, not all CT that are ingested are also excreted. The effect of PEG treatment on the N excretion pathway was independent of the CP level.

Inclusion of a tannin-rich legume in the diet of beef steers reduces greenhouse gas emissions from their excreta

“…Greater N concentration in urine of animals fed 100SL than 50SL and 0SL can be also attributable to a high CP intake. High CP intake without a concomitant increase in energy supply overloads ruminal microbes, increasing ammonia production in the rumen, thereby, leading to more ammonia being absorbed by the ruminal wall of animals fed 100SL than 0SL 20 . With that, more ammonia was proportionally being converted to urea and excreted in the urine from animals fed 100SL than those fed the other diets 21 .…”

Potential use of wild Onobrychis species for climate change mitigation and adaptation

“…Feeding forage legumes containing condensed tannins (CT), such as Onobrychis species, to ruminants has the potential to increase protein utilization, improve zootechnic performance, and prevent bloating, unlike other legumes such as M. sativa L. Moreover, legumes containing CT, decrease rumen protein degradation and increase the plasma level of essential amino acids. Furthermore, they reduce urinary N excretion and ruminal methane (CH 4 ) emissions, which are contributors to environmental pollution and climate change (Bhattarai et al, 2016(Bhattarai et al, , 2018Seoni et al, 2021;Sheppard et al, 2019).…”

A Review: The Importance of the Enteric Methane Production Measurement Methods and Mitigation Strategies in Ruminant Animals

“…TANs can also reduce the digestion of protein in the rumen and the entire gastrointestinal tract (Waghorn, 2008). Therefore, the intake of TANs in combination with a medium-poor quality diet (e.g., insufficient crude protein in the diet) may not generate nutritional benefits and is detrimental to performance (Seoni et al, 2021). For example, some studies have reported negative effects of dietary supplementation with TANs on digestibility, productive performance, and ruminal fermentation (Adejoro et al, 2020), while other studies have not observed significant effects on digestibility, productive performance, CH4 emissions, and urinary and fecal nitrogen excretion in response to TAN supplementation (Adejoro et al, 2020).…”