Interpretive Summary: Plant tannin for grazing ruminant growth

By: Cesar H E C Poli, Jalise F Tontini, Luiza R Jacondino, Juan J Villalba, James P Muir, Luis O Tedeschi

Implications

• This paper presents recent research that provides insights into how tannins influence forage intake, rumen microbial growth, volatile fatty acid production, and grazing behavior in ruminants.
• Including tannins in grazing diets presents a double-edged sword, offering potential benefits for ruminant growth efficiency, methane mitigation, and nutrient utilization while posing challenges to digestibility and feed intake.
• Tannins, naturally occurring in plants, interact with ruminant ingestive behavior and rumen microbes, significantly affecting fermentation processes, nutrient absorption, and animal growth, thereby impacting environmental sustainability.
• The key lies in balancing tannin levels and type (e.g., condensed, hydrolyzable, phlorotannins) to optimize their positive effects without compromising animal performance. The dual nature of tannins highlights their complex role in animal nutrition and health, as well as in the diversity of feeding responses exhibited by ruminant livestock.

Introduction

Tannins have long been used to preserve and tan leather. There are reports of tannin use dating back to the late Neolithic period (Falcão and Araujo, 2018), when aqueous extracts with plant parts were used to prevent the degradation of slaughtered animal skins, transforming them into leather. Tannins are important in leather tanning because their molecules bind to proteins, causing the fibers to break down. Chemically, tannins are polyphenolic compounds characterized by aromatic compounds linked to hydroxyl groups that bind to proteins through hydrogen bonds (Naumann et al., 2017; Tedeschi et al., 2021b). In addition to binding to proteins, tannins can also precipitate polysaccharides, alkaloids, and metal ions (Falcão and Araujo, 2018). They can have antioxidant capacity, serving as a substance that mitigates the negative effects of free radicals in oxidative stress (Mora et al., 2022).

Read the full article in Animal Frontiers, Factors Affecting Animal Growth.