Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall
Fescue toxicosis is caused by grazing ergot alkaloid-producing endophyte (<i>Epichloë coenophiala</i>)-infected tall fescue (E+). Summer grazing of E+ leads to decreased productivity, associated impaired thermoregulation, and altered behavior. The goal of this study was to determine the...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-05-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/15/5/343 |
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| author | Ignacio M. Llada Jeferson M. Lourenco Mikayla M. Dycus Jessica M. Carpenter Garret Suen Nicholas S. Hill Nikolay M. Filipov |
| author_facet | Ignacio M. Llada Jeferson M. Lourenco Mikayla M. Dycus Jessica M. Carpenter Garret Suen Nicholas S. Hill Nikolay M. Filipov |
| author_sort | Ignacio M. Llada |
| collection | DOAJ |
| description | Fescue toxicosis is caused by grazing ergot alkaloid-producing endophyte (<i>Epichloë coenophiala</i>)-infected tall fescue (E+). Summer grazing of E+ leads to decreased productivity, associated impaired thermoregulation, and altered behavior. The goal of this study was to determine the role of E+ grazing-climate interaction on animal behavior and thermoregulation during late fall. Eighteen Angus steers were placed on nontoxic (NT), toxic (E+) and endophyte-free (E−) fescue pastures for 28 days. Physiological parameters, such as rectal temperature (RT), respiration rate (RR), ear and ankle surface temperature (ET, AT), and body weights, were measured. Skin surface temperature (SST) and animal activity were recorded continuously with temperature and behavioral activity sensors, respectively. Environmental conditions were collected using paddocks-placed data loggers. Across the trial, steers on E+ gained about 60% less weight than the other two groups. E+ steers also had higher RT than E− and NT, and lower SST than NT post-pasture placement. Importantly, animals grazing E+ spent more time lying, less time standing, and took more steps. These data suggest that late fall E+ grazing impairs core and surface temperature regulation and increases non-productive lying time, which may be partly responsible for the observed decreased weight gains. |
| first_indexed | 2024-03-11T03:15:49Z |
| format | Article |
| id | doaj.art-d3d6e7730ff3439698dd86ddf5bf5b4c |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-11T03:15:49Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-d3d6e7730ff3439698dd86ddf5bf5b4c2023-11-18T03:33:42ZengMDPI AGToxins2072-66512023-05-0115534310.3390/toxins15050343Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late FallIgnacio M. Llada0Jeferson M. Lourenco1Mikayla M. Dycus2Jessica M. Carpenter3Garret Suen4Nicholas S. Hill5Nikolay M. Filipov6Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USADepartment of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USADepartment of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USADepartment of Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USADepartment of Bacteriology, University of Wisconsin, Madison, WI 53706, USADepartment of Crop and Soil Sciences, College of Agriculture, University of Georgia, Athens, GA 30602, USAInterdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USAFescue toxicosis is caused by grazing ergot alkaloid-producing endophyte (<i>Epichloë coenophiala</i>)-infected tall fescue (E+). Summer grazing of E+ leads to decreased productivity, associated impaired thermoregulation, and altered behavior. The goal of this study was to determine the role of E+ grazing-climate interaction on animal behavior and thermoregulation during late fall. Eighteen Angus steers were placed on nontoxic (NT), toxic (E+) and endophyte-free (E−) fescue pastures for 28 days. Physiological parameters, such as rectal temperature (RT), respiration rate (RR), ear and ankle surface temperature (ET, AT), and body weights, were measured. Skin surface temperature (SST) and animal activity were recorded continuously with temperature and behavioral activity sensors, respectively. Environmental conditions were collected using paddocks-placed data loggers. Across the trial, steers on E+ gained about 60% less weight than the other two groups. E+ steers also had higher RT than E− and NT, and lower SST than NT post-pasture placement. Importantly, animals grazing E+ spent more time lying, less time standing, and took more steps. These data suggest that late fall E+ grazing impairs core and surface temperature regulation and increases non-productive lying time, which may be partly responsible for the observed decreased weight gains.https://www.mdpi.com/2072-6651/15/5/343tall fescue<i>Epichloë coenophiala</i>fescue toxicosispasture behaviorthermoregulation |
| spellingShingle | Ignacio M. Llada Jeferson M. Lourenco Mikayla M. Dycus Jessica M. Carpenter Garret Suen Nicholas S. Hill Nikolay M. Filipov Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall Toxins tall fescue <i>Epichloë coenophiala</i> fescue toxicosis pasture behavior thermoregulation |
| title | Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall |
| title_full | Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall |
| title_fullStr | Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall |
| title_full_unstemmed | Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall |
| title_short | Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall |
| title_sort | behavioral and physiological alterations in angus steers grazing endophyte infected toxic fescue during late fall |
| topic | tall fescue <i>Epichloë coenophiala</i> fescue toxicosis pasture behavior thermoregulation |
| url | https://www.mdpi.com/2072-6651/15/5/343 |
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