The Occurrence, Biosynthesis, and Molecular Structure of Proanthocyanidins and Their Effects on Legume Forage Protein Precipitation, Digestion and Absorption in the Ruminant Digestive Tract

Abstract

Forages grown in temperate regions, such as alfalfa (Medicago sativa L.) and white clover (Trefolium repens L.), typically have a high nutritional value when fed to ruminants. Their high protein content and degradation rate result, however, in poor utilization of protein from the forage resulting in excessive excretion of nitrogen into the environment by the animal. Proanthocyanindins (also known as condensed tannins) found in some forage legumes such as birdsfoot trefoil (Lotus corniculatus L.), bind to dietary protein and can improve protein utilization in the animal. This review will focus on (1) the occurrence of proanthocyanidins; (2) biosynthesis and structure of proanthocyanidins; (3) effects of proanthocyanidins on protein metabolism; (4) protein precipitating capacity of proanthocyanidins and their effects on true intestinal protein adsorption by ruminants; and (5) effect on animal health, animal performance and environmental emissions.

HPLC-qTOF-MS/MS-Based Profiling of Flavan-3-ols and Dimeric Proanthocyanidins in Berries of Two Muscadine Grape Hybrids FLH 13-11 and FLH 17-66

“…Moreover, PAs are important nutritional components to protect ruminant animals, such as dairy cows, from pasture bloat, a disease caused by high protein contents in forage crops, such as alfalfa [4]. Furthermore, PAs provide multiple health benefits for humans, such as antioxidative activity against free radicals-mediated diseases [5,6]. The presence of PAs also contributes to the astringent and bitter tastes and maintain color stability of juices and wine [7].…”

Effect of the method of preservation on the chemical composition and in vitro fermentation characteristics in two legumes rich in condensed tannins

“…However, these legumes have differences in the fractions of extractable CT (ECT), protein bound-CT (PBCT) and fibre bound-CT (FBCT), which influence the bioactivity of the CT (Jonker and Yu, 2017).…”

“…Condensed tannins reduce microbial action, gas and methane (CH4) production and ammonia (NH3-N) content (Frutos et al, 2004;Ramírez-Restrepo and Barry, 2005;Jonker and Yu, 2017), depending on the species of CT-containing legume (Huyen et al, 2016;Grosse-Brinkhaus et al, 2017). To the best of our knowledge, the effects of preservation on ruminal…”

The complete chloroplast genome sequence of Sainfoin (Onobrychis viciifolia)

“…Ruminant animals fed with sainfoin that is rich in condensed tannins will not suffer from bloat (Lagrange and Villalba 2019). Meanwhile, moderate levels of condensed tannins in sainfoin have positive effects on digestion and absorption of amino acids, urinary nitrogen secretion and animal performance (Hayot Carbonero et al 2011;Huyen et al 2016;Jonker and Yu 2017). In addition, allelochemicals of sainfoin can inhibit the growth of weeds (Cheng and Cheng 2015).…”