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ARS Home » Pacific West Area » Logan, Utah » Poisonous Plant Research » Research » Publications at this Location » Publication #331448

Title: Preference by horses for bedding pellets made from switchgrass (Panicum virgatum) straw

Author
item Pfister, James
item Lee, Stephen
item ARNETT, DAN - Ernst Biomass Llc
item Panter, Kip

Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2017
Publication Date: 6/1/2017
Citation: Pfister, J.A., Lee, S.T., Arnett, D., Panter, K.E. 2017. Preference by horses for bedding pellets made from switchgrass (Panicum virgatum) straw. Professional Animal Scientist. 33(3):349–356. https://doi.org/10.15232/pas.2016-01585.
DOI: https://doi.org/10.15232/pas.2016-01585

Interpretive Summary: The bedding system used for stalled horses can impact their health and well-being. This study examined the saponin concentration in switchgrass (Panicum virgatum) straw, and bedding pellets made from switchgrass straw. Further, this study determined the palatability of bedding pellets made from switchgrass straw and southern pine wood to horses. Saponins in switchgrass have been implicated in photosensitization in livestock, including horses. The average concentration of the saponins dichotomin and protodioscin in switchgrass bales was 0.37 µg/g and 0.19 µg/g, respectively. The concentration of dichotomin decreased 38% from bales to the final pellets from a combination of environmental factors and dilution with other plant material. In the initial 8-day trial, horses were tested to determine their preference for 1) switchgrass straw bedding pellets, 2) Omolene 400 horse feed (sweet feed), 3) alfalfa hay cubes, and 4) Equine Pine Pellet bedding. In a second 4-day trial, barley straw was substituted for Omolene. On each test day, the fasted horses were given 30 minutes to consume the offered feeds and bedding pellets. Horses preferred both alfalfa cubes and Omolene (consumption > 99% of offered), while rejecting both the switchgrass bedding pellets and the pine bedding pellets (< 0.6% of offered) during the first trial period. When barley straw was substituted for Omolene sweet feed in the second 4-day period, horses consumed a small amount of barley straw (6% of offered), and again horses rejected (< 0.2 % of offered) both the switchgrass and pine bedding pellets. The risk of poisoning from horses ingesting bedding pellets made with switchgrass straw is essentially nonexistent as the pellets are not palatable to horses.

Technical Abstract: The bedding system used for stalled horses can impact their health and well-being. This study examined the saponin concentration in switchgrass (Panicum virgatum) straw, and bedding pellets made from switchgrass straw. Further, this study determined the palatability of bedding pellets made from switchgrass straw and southern pine wood to horses. Steroidal saponins have been implicated in hepatogenous photosensitization in livestock, including horses. The average concentration of the saponins dichotomin and protodioscin in switchgrass bales was 0.37 µg/g and 0.19 µg/g, respectively. The concentration of dichotomin decreased 38% from bales to the final pellets from a combination of environmental factors and dilution with other plant material. In the initial 8-day trial, horses were tested to determine their preference for 1) switchgrass straw bedding pellets, 2) Omolene 400 horse feed, 3) alfalfa hay cubes, and 4) Equine Pine Pellet bedding. In a second 4-day trial, barley straw was substituted for Omolene. On each test day, the fasted horses were given 30 minutes to consume the offered feeds and bedding pellets. Horses preferred both alfalfa cubes and Omolene (consumption > 99% of offered), while rejecting both the switchgrass bedding pellets and the pine bedding pellets (< 0.6% of offered) during the first trial period. When barley straw was substituted for Omolene in the second 4-day period, horses consumed a small amount of straw (6% of offered), and again horses rejected (< 0.2 % of offered) both the switchgrass and pine bedding pellets. The risk of intoxication from horses ingesting bedding pellets made with switchgrass straw is essentially nil as the pellets are not palatable to horses.