On-Farm Methane Mitigation and Animal Health Assessment of a Commercially Available Tannin Supplement in Organic Dairy Heifers

Ashley Schilling-Hazlett; Edward J Raynor; Logan Thompson; Juan Velez; Sara Place; Kim Stackhouse-Lawson

doi:10.3390/ani14010009

On-Farm Methane Mitigation and Animal Health Assessment of a Commercially Available Tannin Supplement in Organic Dairy Heifers

Animals (Basel). 2023 Dec 19;14(1):9. doi: 10.3390/ani14010009.

Authors

Ashley Schilling-Hazlett¹, Edward J Raynor¹, Logan Thompson², Juan Velez³, Sara Place¹, Kim Stackhouse-Lawson¹

Affiliations

¹ CSU AgNext, Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA.
² Department of Animal Science and Industry, Kansas State University, Manhattan, KS 66502, USA.
³ Aurora Organic Dairy, Boulder, CO 80302, USA.

Abstract

The objective of this experiment was to demonstrate the effectiveness of a commercially available tannin product (Silvafeed^® ByPro, 70% tannic acid) as an enteric methane (CH₄) mitigation and preventative animal health strategy in Holstein heifers (BW = 219 ± 17 kg; 9 mo), reared under organic production system requirements. Twenty heifers were randomly assigned to one of four commercial tannin supplementation treatments as follows: 0% (0 g/hd/d; CON), 0.075% (~5 g/hd/d; LOW), 0.15% (~10 g/hd/d; MED), and 0.30% (~21 g/hd/d; HIG) of dry matter intake (DMI). Heifers received their treatment in individual animal feeding stanchions and were fed a basal total mixed ration (TMR) through four SmartFeed Pro intake measurement bunk systems (C-Lock Inc., Rapid City, SD, USA) for 45 d. An automatic head chamber system (AHCS; i.e., GreenFeed, C-Lock Inc., Rapid City, SD, USA) was used to continuously evaluate enteric CH₄ production. No effect was observed among the treatments for CH₄ emissions (p ≥ 0.55), animal performance (p ≥ 0.38), or oxidative stress biomarker concentration (p ≥ 0.55). Superoxide dismutase (SOD) and reduced glutathione (GSH) concentrations exhibited a linear response to increasing tannin dose (p = 0.003), indicating a potential tannin effect on the antioxidant status of dairy heifers. This observation may encourage future tannin research relating to animal health, which may be of particular interest to organic dairy systems. The results of this study suggest that tannin supplementation at 0%, 0.075%, 0.15%, and 0.30% of DMI, did not alter CH₄ emissions, animal performance, or oxidative stress biomarker concentration in organic Holstein heifers when assessed under an on-farm research approach. Further, the results of this study affirm the challenges associated with on-farm research and the development of climate-smart strategies that are capable of mitigating climate impacts in less controlled environments under standard working conditions.

Keywords: animal health; animal performance; climate-smart conservation practices; methane; on-farm research; organic dairy.

Grants and funding

This research received no external funding.