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Evans TJ, Romano MC. Toxigenic Endophyte-Infected Tall Fescue and Ergot Alkaloids. Vet Clin North Am Equine Pract 2024; 40:95-111. [PMID: 38281896 DOI: 10.1016/j.cveq.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024] Open
Abstract
"Fescue toxicosis" and reproductive ergotism present identical toxidromes in late-gestational mares and, likely, other equids. Both toxic syndromes are caused by ergopeptine alkaloids (EPAs) of fungal origin, and they are collectively referred to as equine ergopeptine alkaloid toxicosis (EEPAT). EPAs are produced by either a toxigenic endophyte (Epichloë coenophiala) in tall fescue and/or a nonendophytic fungus (Claviceps purpurea), infecting small grains and grasses. EEPAT can cause hypoprolactinemia-induced agalactia/dysgalactia, prolonged gestation, dystocia, and other reproductive abnormalities in mares, as well as failure of passive transfer in their frequently dysmature/overmature/postmature foals. Prevention relies on eliminating exposures and/or reversing hypoprolactinemia.
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Affiliation(s)
- Tim J Evans
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri-Columbia, W226 Veterinary Medicine Building, 1520 Rollins Street, Columbia, MO 65211, USA.
| | - Megan C Romano
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food, and Environment, University of Kentucky Veterinary Diagnostic Laboratory, University of Kentucky, 1490 Bull Lea Road, PO Box 14125, Lexington, KY 40512-4125, USA
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2
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Llada IM, Mote RS, Hill NS, Lourenco JM, Jones DP, Suen G, Ross MK, Filipov NM. Ruminal ergovaline and volatile fatty acid dynamics: Association with poor performance and a key growth regulator in steers grazing toxic tall fescue. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 105:104354. [PMID: 38151218 DOI: 10.1016/j.etap.2023.104354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/22/2023] [Indexed: 12/29/2023]
Abstract
Fescue toxicosis (FT) is produced by an ergot alkaloid (i.e., ergovaline [EV])-producing fungus residing in toxic fescue plants. Associations between EV, decreased weight gain and ruminal volatile fatty acids are unclear. Feces, rumen fluid, and blood were collected from 12 steers that grazed non-toxic (NT) or toxic (E +) fescue for 28 days. The E + group exhibited decreased propionate (P), increased acetate (A), and increased ruminal A:P ratio, with similar trends in feces. Plasma GASP-1 (G-Protein-Coupled-Receptor-Associated-Sorting-Protein), a myostatin inhibitor, decreased (day 14) only in E + steers. Ergovaline was present only in E + ruminal fluid and peaked on day 14. The lower ruminal propionate and higher A:P ratio might contribute to FT while reduced GASP-1 might be a new mechanism linked to E + -related weight gain reduction. Day 14 ergovaline zenith likely reflects ruminal adaptations favoring EV breakdown and its presence only in rumen points to local, rather than systemic effects.
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Affiliation(s)
- I M Llada
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States
| | - R S Mote
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States
| | - N S Hill
- Department of Crop and Soil Sciences, United States
| | - J M Lourenco
- Department of Animal and Dairy Sciences, University of Georgia, Athens, GA, United States
| | - D P Jones
- Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University, Atlanta, GA, United States
| | - G Suen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - M K Ross
- Center for Environmental Health Sciences, Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, United States
| | - N M Filipov
- Interdisciplinary Toxicology Program, United States; Department of Physiology and Pharmacology, United States.
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Llada IM, Lourenco JM, Dycus MM, Carpenter JM, Suen G, Hill NS, Filipov NM. Behavioral and Physiological Alterations in Angus Steers Grazing Endophyte-Infected Toxic Fescue during Late Fall. Toxins (Basel) 2023; 15:toxins15050343. [PMID: 37235377 DOI: 10.3390/toxins15050343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/12/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023] Open
Abstract
Fescue toxicosis is caused by grazing ergot alkaloid-producing endophyte (Epichloë coenophiala)-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.
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Affiliation(s)
- Ignacio M Llada
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
- Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA
| | - Jeferson M Lourenco
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USA
| | - Mikayla M Dycus
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USA
| | - Jessica M Carpenter
- Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA
| | - Garret Suen
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Nicholas S Hill
- Department of Crop and Soil Sciences, College of Agriculture, University of Georgia, Athens, GA 30602, USA
| | - Nikolay M Filipov
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
- Department of Physiology and Pharmacology, University of Georgia, Athens, GA 30602, USA
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4
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Cowan VE, Chohan M, Blakley BR, McKinnon J, Anzar M, Singh J. Chronic ergot exposure in adult bulls suppresses prolactin but minimally impacts results of typical breeding soundness exams. Theriogenology 2023; 197:71-83. [PMID: 36476505 DOI: 10.1016/j.theriogenology.2022.11.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 11/15/2022] [Accepted: 11/24/2022] [Indexed: 11/27/2022]
Abstract
Canadian standards allow ≤3000 μg ergot alkaloids/kg cattle feed. A concentration-response relationship was hypothesized between ergot in feed and reductions in plasma prolactin, sperm motility, sperm function, and increase in sperm abnormalities. The study consisted of pre-treatment (12 weeks), treatment (9 weeks), and post-treatment periods (10 weeks). Adult bulls were fed 1113 (n = 8; low ergot group) or 2227 (n = 6; high) μg/kg of dry matter intake. Endpoints were measured every two weeks. Ejaculates were analyzed for sperm concentration, total and progressive motility, plasma membrane and acrosome integrity, mitochondrial membrane potential and sperm abnormalities. Data were analyzed by repeated measures MIXED PROC in SAS. Average outside ambient temperature during the pre-treatment, treatment, and post-treatment periods was -13 (-31 to 1), 0.5 (-18 to 19), and 21 (13-28) °C. Plasma prolactin decreased markedly during treatment (-52.4%; Experimental period p < 0.01). Rectal temperature increased during the treatment and post-treatment periods (EP p < 0.01) but was within the normal physiological range. Bull weight increased during the study (EP p < 0.01). Scrotal circumference in low ergot group increased during treatment (+0.8 cm; Tx∗EP p = 0.05). Progressive motility in high ergot group decreased during treatment (-7%; Tx∗EP p = 0.05), however, semen volume and sperm concentrations were unaffected (p ≥ 0.11). Live sperm with high and medium MMP decreased during treatment (-1.4 and -3.7%; EP p < 0.01). Results suggest that feeding ≤2227 μg ergot alkaloids/kg has only minor effects on adult bull semen quality.
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Affiliation(s)
- Vanessa E Cowan
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N5B4, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N5B3, Canada
| | - Moveed Chohan
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N5B4, Canada
| | - Barry R Blakley
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N5B4, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N5B3, Canada
| | - John McKinnon
- Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, S7N5A8, Canada
| | - Muhammad Anzar
- Canadian Animal Genetic Resource Program, Agriculture and Agri-Food Canada, Saskatoon, SK, S7N0X2, Canada
| | - Jaswant Singh
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N5B4, Canada.
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Prescribed burning of endophyte-infected tall fescue plots: Effects on forage production, ergot-like alkaloid concentrations, and botanical composition. APPLIED ANIMAL SCIENCE 2022. [DOI: 10.15232/aas.2022-02324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Davis BE, Hamilton TA, Johns JT, Harmon DL, Klotz JL, Weinert-Nelson JR, Goodman JP, May J, Ji H, Schrick FN, Flythe MD. Conventional loose mineral with added red clover leaf (Trifolium pratense L.) reverses vasoconstriction associated with tall fescue toxicosis in steers. Anim Feed Sci Technol 2022. [DOI: 10.1016/j.anifeedsci.2022.115523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Alfaro GF, Moisá SJ. Fescue toxicosis: a detrimental condition that requires a multiapproach solution. Anim Front 2022; 12:23-28. [PMID: 36268172 PMCID: PMC9564997 DOI: 10.1093/af/vfac063] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Gastón F Alfaro
- Department of Animal Sciences, Auburn University, Auburn, AL, USA
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Leaf Mycobiome and Mycotoxin Profile of Warm-Season Grasses Structured by Plant Species, Geography, and Apparent Black-Stroma Fungal Structure. Appl Environ Microbiol 2022; 88:e0094222. [PMID: 36226941 PMCID: PMC9642016 DOI: 10.1128/aem.00942-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Grasses harbor diverse fungi, including some that produce mycotoxins or other secondary metabolites. Recently, Florida cattle farmers reported cattle illness, while the cattle were grazing on warm-season grass pastures, that was not attributable to common causes, such as nutritional imbalances or nitrate toxicity. To understand correlations between grass mycobiome and mycotoxin production, we investigated the mycobiomes associated with five prominent, perennial forage and weed grasses [Paspalum notatum Flügge, Cynodon dactylon (L.) Pers., Paspalum nicorae Parodi, Sporobolus indicus (L.) R. Br., and Andropogon virginicus (L.)] collected from six Florida pastures actively grazed by livestock. Black fungal stromata of Myriogenospora and Balansia were observed on P. notatum and S. indicus leaves and were investigated. High-throughput amplicon sequencing was applied to delineate leaf mycobiomes. Mycotoxins from P. notatum leaves were inspected using liquid chromatography-mass spectrometry (LC-MS/MS). Grass species, cultivars, and geographic localities interactively affected fungal community assemblies of asymptomatic leaves. Among the grass species, the greatest fungal richness was detected in the weed S. indicus. The black fungal structures of P. notatum leaves were dominated by the genus Myriogenospora, while those of S. indicus were codominated by the genus Balansia and a hypermycoparasitic fungus of the genus Clonostachys. When comparing mycotoxins detected in P. notatum leaves with and without M. atramentosa, emodin, an anthraquinone, was the only compound which was significantly different (P < 0.05). Understanding the leaf mycobiome and the mycotoxins it may produce in warm-season grasses has important implications for how these associations lead to secondary metabolite production and their subsequent impact on animal health. IMPORTANCE The leaf mycobiome of forage grasses can have a major impact on their mycotoxin contents of forage and subsequently affect livestock health. Despite the importance of the cattle industry in warm-climate regions, such as Florida, studies have been primarily limited to temperate forage systems. Our study provides a holistic view of leaf fungi considering epibiotic, endophytic, and hypermycoparasitic associations with five perennial, warm-season forage and weed grasses. We highlight that plant identity and geographic location interactively affect leaf fungal community composition. Yeasts appeared to be an overlooked fungal group in healthy forage mycobiomes. Furthermore, we detected high emodin quantities in the leaves of a widely planted forage species (P. notatum) whenever epibiotic fungi occurred. Our study demonstrated the importance of identifying fungal communities, ecological roles, and secondary metabolites in perennial, warm-season grasses and their potential for interfering with livestock health.
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Effects of Tall Fescue Endophyte Type and Dopamine Receptor D2 Genotype on Cow-Calf Performance during Late Gestation and Early Lactation. Toxins (Basel) 2021; 13:toxins13030195. [PMID: 33803203 PMCID: PMC8000531 DOI: 10.3390/toxins13030195] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 11/17/2022] Open
Abstract
Grazing endophyte-infected, toxic tall fescue reduces cow/calf production; therefore, this study examines alternate strategies such as use of novel endophyte fescue varieties during late gestation and early lactation or genetic selection of resistant cows. Pregnant cows (n = 75) were randomly assigned to fescue endophyte type: 1) endophyte-infected ergot alkaloid producing tall fescue (E+) or 2) novel endophyte-infected, non-toxic tall fescue (NOV) within maternal (A|A, n = 38 and G|G, n = 37) DRD2 genotype to examine changes in cow/calf performance and milk production during late gestation and early lactation. Grazing E+ fescue pastures during late gestation reduced cow body weight gain but did not alter calf birth weight compared to NOV. Milk production and calf ADG during the first 30 day of lactation were lower for E+ than NOV. The calving rate was reduced, but not calving interval for E+ cows. The adjusted 205-day weight of calves was lower in those grazing E+ with their dams compared to NOV. There were no interactions between DRD2 genotype and fescue endophyte type indicating that genotype was not associated with response to E+ fescue in this study. Overall, grazing NOV tall fescue pastures rather than E+ during critical stages of production improved cow gain during late gestation, calving rate, early milk production and calf growth.
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Valente EEL, Klotz JL, Ahn G, McLeod KR, Herzing HM, King M, Harmon DL. Ergot alkaloids reduce circulating serotonin in the bovine. J Anim Sci 2021; 98:5981672. [PMID: 33188392 DOI: 10.1093/jas/skaa362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022] Open
Abstract
Ergot alkaloids can interact with several serotonin (5-hydroxytryptamine [5-HT]) receptors provoking many physiological responses. However, it is unknown whether ergot alkaloid consumption influences 5-HT or its metabolites. Thus, two experiments were performed to evaluate the effect of ergot alkaloid feeding on 5-HT metabolism. In exp. 1, 12 Holstein steers (260 ± 3 kg body weight [BW]) were used in a completely randomized design. The treatments were the dietary concentration of ergovaline: 0, 0.862, and 1.282 mg/kg of diet. The steers were fed ad libitum, kept in light and temperature cycles mimicking the summer, and had blood sampled before and 15 d after receiving the treatments. The consumption of ergot alkaloids provoked a linear decrease (P = 0.004) in serum 5-HT. However, serum 5-hydroxytryptophan and 5-hydroxyindoleacetic acid did not change (P > 0.05) between treatments. In exp. 2, four ruminally cannulated Holstein steers (318 ± 3 kg BW) were used in a 4 × 4 Latin square design to examine the difference between seed sources on 5-HT metabolism. Treatments were: control-tall fescue seeds free of ergovaline, KY 32 seeds (L42-16-2K32); 5Way-endophyte-infected seeds, 5 way (L152-11-1739); KY31-endophyte-infected seeds, KY 31 (M164-16-SOS); and Millennium-endophyte-infected seeds, 3rd Millennium (L108-11-76). The endophyte-infected seed treatments were all adjusted to provide an ergovaline dosage of 15 μg/kg BW. The basal diet provided 1.5-fold the net energy requirement for maintenance. The seed treatments were dosed directly into the rumen before feeding. The experiment lasted 84 d and was divided into four periods. In each period, the steers received seeds for 7 d followed by a 14-d washout. Blood samples were collected on day 0 (baseline) and day 7 for evaluating the treatment response in each period. A 24 h urine collection was performed on day 7. Similar to exp. 1, serum 5-HT decreased (P = 0.008) with the consumption of all endophyte-infected seed treatments. However, there was no difference (P > 0.05) between the infected seeds. The urinary excretion of 5-hydroxyindoleacetic acid in the urine was not affected (P > 0.05) by the presence of ergot alkaloids. In conclusion, the consumption of ergot alkaloids decreases serum 5-HT with no difference between the source of endophyte-infected seeds in the bovine.
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Affiliation(s)
- Eriton E L Valente
- Department of Animal Science, State University of Western Parana, Marechal Cândido Rondon, PR, Brazil
| | - James L Klotz
- Forage-Animal Production Research Unit, USDA-ARS, Lexington, KY
| | - Gyuchul Ahn
- Department of Animal and Food Science, University of Kentucky, Lexington, KY
| | - Kyle R McLeod
- Department of Animal and Food Science, University of Kentucky, Lexington, KY
| | - Hannah M Herzing
- Department of Animal and Food Science, University of Kentucky, Lexington, KY
| | - Mindy King
- Department of Animal and Food Science, University of Kentucky, Lexington, KY
| | - David L Harmon
- Department of Animal and Food Science, University of Kentucky, Lexington, KY
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Feeding yearling Angus bulls low-level ergot daily for 9 weeks decreased serum prolactin concentrations and had subtle effects on sperm end points. Theriogenology 2020; 161:187-199. [PMID: 33340752 DOI: 10.1016/j.theriogenology.2020.11.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 12/26/2022]
Abstract
Our objective was to determine whether feeding yearling bulls with the higher recommended Canadian limit of ergot alkaloids (∼3 mg/kg dry matter intake, DMI) would affect sperm characteristics and plasma prolactin concentrations. Aberdeen Angus bulls (12-13 mo old, n = 7/group) allocated by blocking for sperm concentration and body weight, were fed placebo or ergot alkaloids in gelatin capsules (60 μg/kg body weight daily, 3.4 mg/kg of DMI) for 9 wk. Semen samples were collected weekly by electroejaculation and examined with a computer assisted semen analyzer (CASA) and flow cytometry, for the intervals 5 wk before (Pre-exposure period), 9 wk during (Exposure period) and 9 wk after (Post-exposure period) treatment. Weekly plasma samples were analyzed for prolactin by radioimmunoassay. Plasma prolactin concentrations decreased markedly (mean ± SEM, 16.74 ± 3.70 in Exposure and 33.42 ± 3.08 ng/mL in Post-Exposure periods; P < 0.01) compared to Control (67.54 ± 21.47 and 42.59 ± 15.06 ng/mL). Treatment did not affect (P ≥ 0.17) body weight gain, sperm concentration, sperm count/ejaculate, motility or percent live sperm. Averaged over the exposure and post-exposure durations, the scrotal circumference was smaller (P = 0.02) by 2.7% in the Ergot group. Progressive motility remained unchanged from 59.92 ± 2.31% in Exposure to 59.61 ± 2.59% in Post-Exposure periods, compared to marked increase in Control (61.42 ± 1.60% to 67.52 ± 1.47%; P = 0.02). Straight-line sperm velocity decreased (-3.15 ± 1.53 μm/s) from exposure to post-exposure periods in Ergot group (P = 0.04) versus an increase (2.96 ± 2.17 μm/s) in Control. Midpiece defects decreased from Exposure to Post-exposure periods in Control group but remained unchanged in Ergot group (trt∗age, P < 0.01). Ergot feeding resulted in a smaller proportion of sperm with medium mitochondrial potential (Ergot: 22.65 ± 0.98%, Control: 24.35 ± 1.05%, P = 0.04). In conclusion, feeding ergot at Canadian permissible limit for 9-wk resulted in a 4-fold decrease in plasma prolactin concentrations. Semen end points were not significantly affected, although there were subtle effects on progressive motility, midpiece defects and mitochondrial membrane potential. Clinical relevance of observed changes requires further evaluation. Results supported our hypothesis that prolonged low-level ergot will adversely affect plasma prolactin. However, semen parameters were partially affected, supporting similar work on fescue toxicosis.
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Rumen and Serum Metabolomes in Response to Endophyte-Infected Tall Fescue Seed and Isoflavone Supplementation in Beef Steers. Toxins (Basel) 2020; 12:toxins12120744. [PMID: 33256042 PMCID: PMC7761436 DOI: 10.3390/toxins12120744] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 11/17/2022] Open
Abstract
Fescue toxicosis impacts beef cattle production via reductions in weight gain and muscle development. Isoflavone supplementation has displayed potential for mitigating these effects. The objective of the current study was to evaluate isoflavone supplementation with fescue seed consumption on rumen and serum metabolomes. Angus steers (n = 36) were allocated randomly in a 2 × 2 factorial arrangement of treatments including endophyte-infected (E+) or endophyte-free (E−) tall fescue seed, with (P+) or without (P−) isoflavones. Steers were provided a basal diet with fescue seed for 21 days, while isoflavones were orally administered daily. Following the trial, blood and rumen fluid were collected for metabolite analysis. Metabolites were extracted and then analyzed by UPLC-MS. The MAVEN program was implemented to identify metabolites for MetaboAnalyst 4.0 and SAS 9.4 statistical analysis. Seven differentially abundant metabolites were identified in serum by isoflavone treatment, and eleven metabolites in the rumen due to seed type (p < 0.05). Pathways affected by treatments were related to amino acid and nucleic acid metabolism in both rumen fluid and serum (p < 0.05). Therefore, metabolism was altered by fescue seed in the rumen; however, isoflavones altered metabolism systemically to potentially mitigate detrimental effects of seed and improve animal performance.
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Eisemann JH, Ashwell MS, Devine TL, Poole DH, Poore MH, Linder KE. Physiological response, function of sweat glands, and hair follicle cycling in cattle in response to fescue toxicosis and hair genotype. J Anim Sci 2020; 98:5717958. [PMID: 31998943 DOI: 10.1093/jas/skaa013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/14/2020] [Indexed: 01/27/2023] Open
Abstract
Fescue toxicosis is a syndrome that results when cattle consume toxic endophyte-infected tall fescue. The objective of this study was to compare the response in physiological variables, sweat gland function, hair follicle cycling, and gene expression to feeding a total mixed ration that included tall fescue haylage and tall fescue seed containing a toxic endophyte (EI) or tall fescue haylage containing a nontoxic novel endophyte (EN) in beef heifers (Angus × Senepol heifers, n = 31) with 2 different hair genotypes. Numbers in each subgroup were as follows: novel endophyte, heterozygous slick (EN-S; n = 8), novel endophyte, homozygous hairy (wild type, EN-W; n = 7), endophyte-infected, heterozygous slick (EI-S; n = 10), and endophyte-infected, homozygous hairy (wild type, EI-W; n = 6). Physiological measurements were taken weekly for 7 wk. Data were analyzed using the MIXED procedure of SAS including dietary fescue treatment (EN vs. EI) and hair genotype (S vs. W) as main effects, day as a repeated measure, and temperature-humidity index (THI) as a covariate. Skin biopsies were taken before treatment initiation and on day 37 of treatment. Average surface temperature (ST) increased as the THI increased (P < 0.0001). Average ST was greater (P < 0.01) for animals fed EI than for animals fed the EN fescue diet, and greater (P < 0.01) for animals with the W genotype compared with animals with the S genotype. The difference between heifers with the S and W genotype was greater at greater THI (genotype × day interaction, P < 0.01). Transepidermal water loss (TEWL) was greater (P < 0.05) for animals with the S genotype compared with the W genotype and greater (P < 0.05) for heifers with the S genotype than for heifers with the W genotype when fed EI (36.7, 38.5, 30.0, and 38.7 g/m2 per hour for EN-W, EN-S, EI-W, and EI-S, respectively). The fraction of follicles in telogen in plucked hair samples for heifers fed EI was greater for animals with the S genotype than the W genotype (fraction in telogen: 0.456, 0.565, 0.297, 0.702 for EN-W, EN-S, EI-W, and EI-S, respectively; diet × genotype interaction, P < 0.05). Fraction of follicles in anagen was the opposite. EI fescue resulted in increased ST, changes in hair follicle cycling that support greater hair growth, and decreased TEWL for heifers with the W genotype compared with S genotype, suggesting greater heat stress in response to EI.
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Affiliation(s)
- Joan H Eisemann
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Melissa S Ashwell
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Thomas L Devine
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Daniel H Poole
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Matt H Poore
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Keith E Linder
- Department of Population, Health and Pathobiology, North Carolina State University, Raleigh, NC
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Koester LR, Poole DH, Serão NVL, Schmitz-Esser S. Beef cattle that respond differently to fescue toxicosis have distinct gastrointestinal tract microbiota. PLoS One 2020; 15:e0229192. [PMID: 32701945 PMCID: PMC7377488 DOI: 10.1371/journal.pone.0229192] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/06/2020] [Indexed: 02/02/2023] Open
Abstract
Tall fescue (Lolium arundinaceum) is a widely used forage grass which shares a symbiosis with the endophytic fungus Epichloë coenophiala. The endophyte produces an alkaloid toxin that provides herbivory, heat and drought resistance to the grass, but can cause fescue toxicosis in grazing livestock. Fescue toxicosis can lead to reduced weight gain and milk yields resulting in significant losses to the livestock industry. The objective of this study was to identify bacterial and fungal communities associated with fescue toxicosis tolerance. In this trial, 149 Angus cows across two farms were continuously exposed to toxic, endophyte-infected, fescue for a total of 13 weeks. Of those 149 cows, 40 were classified into either high (HT) or low (LT) tolerance groups according to their growth performance (weight gain). 20 HT and 20 LT cattle balanced by farm were selected for amplicon sequencing to compare the fecal microbiota of the two tolerance groups. This study reveals significantly (q<0.05) different bacterial and fungal microbiota between HT and LT cattle, and indicates that fungal phylotypes may be important for an animal’s response to fescue toxicosis: We found that fungal phylotypes affiliating to the Neocallimastigaceae, which are known to be important fiber-degrading fungi, were consistently more abundant in the HT cattle. Whereas fungal phylotypes related to the genus Thelebolus were more abundant in the LT cattle. This study also found more pronounced shifts in the microbiota in animals receiving higher amounts of the toxin. We identified fungal phylotypes which were consistently more abundant either in HT or LT cattle and may thus be associated with the respective animal’s response to fescue toxicosis. Our results thus suggest that some fungal phylotypes might be involved in mitigating fescue toxicosis.
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Affiliation(s)
- Lucas R. Koester
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States of America
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States of America
| | - Daniel H. Poole
- Department of Animal Science, North Carolina State University, Raleigh, NC, United States of America
| | - Nick V. L. Serão
- Department of Animal Science, Iowa State University, Ames, IA, United States of America
- * E-mail: (NVS); (SSE)
| | - Stephan Schmitz-Esser
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States of America
- Department of Animal Science, Iowa State University, Ames, IA, United States of America
- * E-mail: (NVS); (SSE)
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15
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Ahn G, Ricconi K, Avila S, Klotz JL, Harmon DL. Ruminal motility, reticuloruminal fill, and eating patterns in steers exposed to ergovaline. J Anim Sci 2020; 98:5680246. [PMID: 31850497 DOI: 10.1093/jas/skz374] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 12/17/2019] [Indexed: 11/14/2022] Open
Abstract
Fescue toxicosis is problematic for growing steers, causing lower DMI and productivity when fed endophyte-infected (E+) tall fescue. A complete understanding of underlying mechanisms of how fescue toxicosis affects growing steers is lacking. Therefore, the overall objective of this multiexperiment study was to determine whether ruminally dosed ergovaline (ERV) affects rumen motility, rumen contents, and eating patterns. In Exp. 1, an 8-h period to assess ruminal motility began 4 h after feeding by monitoring pressure changes using a wireless system for 21 d. Eight ruminally cannulated steers (283 kg BW) were pair fed with alfalfa cubes (1.5 × NEm) and assigned to endophyte free (E-; 0 μg ERV/kg BW/d) or E+ treatment (20 μg ERV/kg BW/d). Overall, E+ steers had more frequent rumen contractions (Seed P = 0.05 and day of feeding P = 0.02). On days 7 to 9, both treatments showed lower frequencies and E- steers had greater amplitude of contractions (P < 0.001) that corresponded with decreased DMI. In Exp. 2, steers remained in pairs assigned in Exp. 1 (322 kg BW), but reversed seed treatments while increasing ERV levels (titrated 0, 5, 10, 15, and 20 μg ERV/kg BW/d over 57 d). There were no differences between E- and E+ for frequency (P = 0.137) or amplitude of contractions (P = 0.951), but increasing ERV dosage, decreased frequency (P = 0.018) and amplitude (P = 0.005), coinciding with lower DMI. In Exp. 3, 8 steers (589 kg) were pair fed and ruminally dosed 15 μg ERV/kg BW/d, and rumen motility data were collected for 21 d. E- steers showed higher amplitude and lower frequency of contractions than E+ steers with seed (P < 0.001), day (P < 0.001), and seed × day (P < 0.04) effects, but rumen fill was not different between E- and E+ (P > 0.29). Serum prolactin concentrations were lower in E+ steers in Exp. 1 to 3. Eating patterns of pair-fed E- and E+ steers were relatively slower in E+ than E- (Exp. 4) by measuring every 2 h across 24 h. Number of meals were higher in E+ than E- steers, but meal duration and meal size were not different between treatments. Rumen content (DM%) tended to be higher in E+ than in E- when steers were fed once a day (P = 0.07), but there was no difference for rumen content (DM%) when E- and E+ steers were fed 12 times a day (P = 0.13). These results suggest the changes in rumen fill associated with fescue toxicosis may be driven more by changes in feeding behavior and eating pattern rather than by changes in motility.
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Affiliation(s)
- Gyuchul Ahn
- Department of Animal and Food Science, University of Kentucky, Lexington, KY 40546
| | - Kara Ricconi
- Department of Animal and Food Science, University of Kentucky, Lexington, KY 40546
| | - Suelen Avila
- USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY 40546
| | - James L Klotz
- USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY 40546
| | - David L Harmon
- Department of Animal and Food Science, University of Kentucky, Lexington, KY 40546
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16
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Johnson K, Busdieker-Jesse N, McClain W, Lancaster P. Feeding strategies and shade type for growing cattle grazing endophyte-infected tall fescue. Livest Sci 2019. [DOI: 10.1016/j.livsci.2019.103829] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Keyser PD, Buehler DA, Hedges K, Hodges J, Lituma CM, Loncarich F, Martin JA. Eastern grasslands: Conservation challenges and opportunities on private lands. WILDLIFE SOC B 2019. [DOI: 10.1002/wsb.1000] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Patrick D. Keyser
- University of Tennessee 2431 Joe Johnson Drive Knoxville TN 37996 USA
| | - David A. Buehler
- University of Tennessee 2431 Joe Johnson Drive Knoxville TN 37996 USA
| | - Kyle Hedges
- Missouri Department of Conservation 412 Killingsworth Avenue Bolivar MO 65613 USA
| | - Jef Hodges
- National Bobwhite Conservation Initiative University of Tennessee 274 Ellington Plant Sciences Building Knoxville TN 37996 USA
| | - Christopher M. Lituma
- Division of Forestry and Natural Resources West Virginia University Morgantown WV 26506 USA
| | - Frank Loncarich
- Missouri Department of Conservation 1510 S Business 49 Neosho MO 64850 USA
| | - James A. Martin
- Warnell School of Forestry and Natural Resources Savannah River Ecology Lab, University of Georgia 180 E Green Street Athens GA 30602 USA
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18
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Poole RK, Devine TL, Mayberry KJ, Eisemann JH, Poore MH, Long NM, Poole DH. Impact of slick hair trait on physiological and reproductive performance in beef heifers consuming ergot alkaloids from endophyte-infected tall fescue1. J Anim Sci 2019; 97:1456-1467. [PMID: 30772895 DOI: 10.1093/jas/skz024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 01/09/2019] [Indexed: 02/07/2023] Open
Abstract
Fescue toxicosis is a multifaceted syndrome common in cattle grazing endophyte-infected tall fescue. The objective of this study was to evaluate the impact of the slick hair trait on physiological and reproductive parameters in heifers experiencing fescue toxicosis. Angus × Senepol heifers (n = 31) were blocked by weight (393.5 ± 17.3 kg) and phenotype relative to hair coat at birth, and randomly fed novel endophyte fescue (EN) or endophyte-infected fescue (EI) haylage in a total mixed ration for 91 d. Weekly measurements were collected to monitor heifer growth and response during ergot alkaloids exposure. Following 28 d of treatment, estrus was synchronized and heifers were inseminated. Ovary mapping and AI pregnancy rate were examined via transrectal ultrasonography. Blood samples were taken for genotyping: slick (S) or wildtype (W). Data were analyzed using repeated measures in PROC MIXED of SAS including fescue treatment (EN vs. EI), genotype (S vs. W), and sample collection time as main effects. Body condition scores were decreased for W heifers compared with S heifers (5.48 vs. 5.66, respectively; P < 0.0001). Surface temperature was greater for EI-W heifers (37.2 °C) compared with other groups (36.4, 36.6, 36.7 °C for EN-S, EN-W, EI-S, respectively; P < 0.05). Serum PRL concentrations were reduced for EI heifers compared with EN heifers (133.5 vs. 163.1 ng/mL, respectively; P < 0.05). The average number of 2 to 4 mm follicles were greater in EI-W heifers (13.8 follicles) compared with other groups (12.2, 10.6, and 11.1 for EN-S, EN-W, and EI-S, respectively; P < 0.0001). However, the average number of preovulatory follicles (≥9 mm) were reduced in EI-W heifers (0.52 follicles) compared with other heifer groups (0.94, 0.88, and 0.85 ± 0.04 for EN-S, EN-W, and EI-S, respectively; P < 0.05). Ovulatory follicle size was smaller in EI-W heifers compared with EN-W heifers (9.14 vs. 11.57 mm, respectively; P = 0.05). Corpus luteum area was reduced in EI-W heifers (235.1 mm2) compared with other heifer groups (297.2, 272.7, and 276.8 mm2 for EN-S, EN-W, and EI-S, respectively; P < 0.05). Concentrations of P4 were greater for EN heifers compared with EI heifers (2.7 vs. 1.8 ng/mL, respectively; P < 0.05). Pregnancy was not established in EI-W heifers (0%) compared with other heifer groups (37.5%, 57.1%, and 62.5% for EN-S, EN-W, and EI-S, respectively; P < 0.05). Overall, the slick hair mutation appears to aid in offsetting the physiological symptoms associated with fescue toxicosis and helps to improve reproductive performance.
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Affiliation(s)
- Rebecca K Poole
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Thomas L Devine
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Kyle J Mayberry
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Joan H Eisemann
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Matt H Poore
- Department of Animal Science, North Carolina State University, Raleigh, NC
| | - Nathan M Long
- Department of Animal and Veterinary Sciences, Clemson University, Clemson, SC
| | - Daniel H Poole
- Department of Animal Science, North Carolina State University, Raleigh, NC
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19
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Impact of Ergot Alkaloids on Female Reproduction in Domestic Livestock Species. Toxins (Basel) 2019; 11:toxins11060364. [PMID: 31234268 PMCID: PMC6628433 DOI: 10.3390/toxins11060364] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/10/2023] Open
Abstract
Fescue toxicosis is a multifaceted syndrome that elicits many negative effects on livestock consuming ergot alkaloids produced by endophyte-infected tall fescue. The economic losses associated with fescue toxicosis are primarily due to reproductive failure including altered cyclicity, suppressed hormone secretion, reduced pregnancy rates, agalactia, and reduced offspring birth weights. For decades, a multitude of research has investigated the physiological and cellular mechanisms of these reproductive failures associated with fescue toxicosis. This review will summarize the various effects of ergot alkaloids on female reproduction in grazing livestock species.
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20
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Volk MJ, Krause TR, Stokes RS, Ireland FA, Shike DW. Effects of extended-release eprinomectin on fescue toxicosis, performance, and reproduction on fall-calving beef cows. Transl Anim Sci 2019; 3:1423-1434. [PMID: 32704907 PMCID: PMC7200507 DOI: 10.1093/tas/txz093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 06/12/2019] [Indexed: 11/14/2022] Open
Abstract
The objective of this experiment was to evaluate effects of extended-release eprinomectin on fescue toxicosis and impacts on performance and reproduction in fall-calving beef cows. Fall-calving Angus × Simmental multiparous cows [n = 335; age = 5.8 ± 2.1 yr; 586.5 ± 6.0 kg body weight (BW); 5.48 ± 0.05 body condition score (BCS)] were stratified by BW, age, and BCS and randomly assigned to one of three treatments. Treatments included a spring injection of extended-release eprinomectin (SERE) on day 0, a fall injection of extended-release eprinomectin injection (FERE) on day 84, and a saline control (CON). All treatments were administered at a rate of 1 mL/50 kg BW. Prior to the experiment, all cows were treated with oral fenbendazole to minimize parasite load. Cows grazed endophyte-infected tall fescue. Hair coat score (HCS), BW, and BCS were recorded on all cattle. Fecal egg count (FEC), respiration rate (RR), horn fly and tick count, hematocrit (% packed cell volume, PCV), and serum prolactin were analyzed on a subset of cows (35/treatment). On day 194, cows were artificially inseminated (AI) and 11 d following AI were exposed to bulls for 51 d. Milk production was estimated on day 210 on a subset of 85 cow-calf pairs (28-29/treatment). There was a tendency for a treatment × time interaction (P = 0.07) for FEC likely driven by an increase in FEC of the CON cattle at day 126 compared to SERE and FERE. There was a tendency for a treatment × time interaction (P = 0.06) for cow BW, largely driven by time differences; however, there was no effect of treatment (P = 0.84) on BW. There was no difference (P ≥ 0.13) in cow PCV, fly and tick count, BCS, HCS, RR, and serum prolactin throughout the experiment. Additionally, there was no difference (P ≥ 0.46) in Julian calving date, calf birth BW, or milk production between treatments. Interestingly, heifer calves born to FERE dams tended to have greater (P = 0.06) weaning BW compared to heifer calves born to CON dams. In addition, there was no difference (P ≥ 0.17) in heat patch scores, AI conception rates, or overall pregnancy rates between treatments. Extended-release eprinomectin did not impact cow growth performance, reproductive performance or fescue toxicity symptoms when grazing endophyte-infected tall fescue; however, calf weaning BW tended to be improved.
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Affiliation(s)
- Mareah J Volk
- Department of Animal Sciences, University of Illinois, Urbana
| | - Taylor R Krause
- Department of Animal Sciences, University of Illinois, Urbana
| | | | - Frank A Ireland
- Department of Animal Sciences, University of Illinois, Urbana
| | - Daniel W Shike
- Department of Animal Sciences, University of Illinois, Urbana
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21
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Volk MJ, Kordas JM, Stokes RS, Ireland FA, Shike DW. Effects of spring administration of extended-release eprinomectin on fescue toxicosis, performance, and reproduction of fall-born beef heifers. Transl Anim Sci 2019; 3:20-28. [PMID: 32704774 PMCID: PMC7200814 DOI: 10.1093/tas/txz015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 02/13/2019] [Indexed: 11/17/2022] Open
Abstract
The objective of this experiment was to assess the effects of eprinomectin, an extended-release injectable parasiticide, on fescue toxicosis and its impacts on beef heifer performance and reproduction. Fall-born Angus × Simmental heifers (age = 246.3 ± 22.4 d; 264.8 ± 21.1 kg body weight [BW]) were randomly assigned to one of two treatments: extended-release eprinomectin injection (ERE; n = 100) or control (CON; saline; n = 99). Treatments were administered at a rate of 1 mL/50 kg BW. Prior to experiment, heifers were dosed with oral fenbendazole to minimize parasite load. All heifers grazed endophyte-infected tall fescue as a single group and were offered a 50:50 supplement mix of corn gluten feed and soybean hulls (2.7 kg as fed per heifer per day). Body condition scores (BCS), BW, hair coat score (HCS), blood, and fecal samples were collected throughout the experiment. A subset of 40 heifers were randomly selected (20 per treatment) to assess respiration rate (RR). On d 138, heifers began a 14-d controlled internal drug release + prostaglandin synchronization protocol. Following artificial insemination (AI), heifers were exposed to five bulls for 71 d. On d 214 and 291, AI and overall pregnancy rates, respectively, were determined. There was a treatment × time interaction (P < 0.01) for BW, BCS, and average daily gain (ADG). The ERE heifers had greater (P < 0.04) BW and BCS compared to CON heifers from d 55 and 112, respectively. In addition, ERE heifers had greater (P ≤ 0.04) ADG from d 0 to 56, 56 to 112, 112 to 171, and 171 to 214; however CON heifers had greater (P < 0.01) ADG from d 214 to 291. There was no treatment × time interaction or treatment difference (P ≥ 0.27) for HCS, RR, and serum prolactin concentrations. However, serum prolactin decreased (P < 0.01) in all heifers over time. There was a treatment × time interaction (P<0.01) for fecal egg counts (FEC). The FEC did not differ (P ≥ 0.32) on d −1 or 55; however, ERE heifers had decreased (P < 0.01) FEC compared with CON heifers on d 111 (1.52 vs. 13.56 eggs per gram). The ERE heifers tended (P = 0.10) to have greater AI pregnancy rates (69% vs. 58%) and had greater (P = 0.01) overall pregnancy rates (84% vs. 68%) than CON heifers. Spring administration of extended-release eprinomectin improved BW, ADG, BCS, and AI and overall pregnancy rates in fall-born beef heifers. However, the underlying mechanism is still unclear, as there were minimal to no differences in HCS, RR, serum prolactin, and FEC.
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Affiliation(s)
- Mareah J Volk
- Department of Animal Sciences, University of Illinois, Urbana, IL
| | - Jessica M Kordas
- Department of Animal Sciences, University of Illinois, Urbana, IL
| | - Rebecca S Stokes
- Department of Animal Sciences, University of Illinois, Urbana, IL
- Present address: KWS Cereals USA, LLC
| | - Frank A Ireland
- Department of Animal Sciences, University of Illinois, Urbana, IL
| | - Daniel W Shike
- Department of Animal Sciences, University of Illinois, Urbana, IL
- Corresponding author:
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22
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Melchior EA, Smith JK, Schneider LG, Mulliniks JT, Bates GE, Flythe MD, Klotz JL, Ji H, Goodman JP, Lee AR, Caldwell JM, Myer PR. Effects of endophyte-infected tall fescue seed and red clover isoflavones on rumen microbial populations and physiological parameters of beef cattle. Transl Anim Sci 2018; 3:315-328. [PMID: 32704802 PMCID: PMC7252513 DOI: 10.1093/tas/txy147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/21/2018] [Accepted: 12/27/2018] [Indexed: 11/13/2022] Open
Abstract
Lolium arundinaceum [(Darbyshire) tall fescue] toxicosis is responsible for substantial beef production losses in the United States, due to its negative effects on reproduction, growth, and feed efficiency. These effects are consequences of toxic alkaloids within tall fescue. Interseeding legumes, such as Trifolium pratense (red clover), into pastures has been shown to mitigate a portion of these effects. Clovers contain isoflavones, which may play a role in tall fescue toxicosis mitigation. The present study utilized 36 Angus steers to determine the effects of daily supplementation with a red clover-isolated isoflavone feed additive on physiological symptoms of tall fescue toxicosis and the rumen microbial environment over a 21-d period. Angus steers were initially stratified based upon their single nucleotide polymorphism genotype at the DRD2 receptor. Treatments were then randomly assigned in a 2 × 2 factorial arrangement within a completely randomized design, where treatment factors consisted of tall fescue seed type (endophyte-infected tall fescue seed vs. endophyte-free tall fescue seed) supplemented with and without the isoflavone additive. Steers that consumed endophyte-infected tall fescue seed had lower serum prolactin concentrations (P = 0.0007), average daily gain (ADG; P = 0.003), final body weight (BW; P = 0.004), and feed efficiency (P = 0.018) when compared with steers that consumed endophyte-free tall fescue seed. Serum insulin-like growth factor-1 (IGF-1) tended to be reduced with supplementation of isoflavones (P = 0.06) but was unaffected by seed type (P ≥ 0.10) and seed by treatment interaction (P ≥ 0.10). Isoflavones reduced serum glucose levels (P = 0.023), but neither seed type, isoflavones, or their interaction affected serum urea nitrogen (SUN), nonesterified fatty acids (NEFA), or insulin (P ≥ 0.10). Volatile fatty acid concentrations, dry matter intake (DMI), ruminal pH, and overall feeding behaviors were also unaffected by seed type or isoflavone treatments (P ≥ 0.10). Twenty-eight ruminal bacteria taxa shifted as a result of seed type or isoflavone treatment (P < 0.05). In this experiment, feeding isoflavones to Angus cattle did not completely mitigate all symptoms of fescue toxicosis. However, dose–response trials may aid future research to determine if dietary supplementation with isoflavones alleviates fescue toxicosis symptoms and promotes livestock growth and performance.
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Affiliation(s)
- Emily A Melchior
- Department of Animal Science, University of Tennessee, Knoxville, TN.,Department of Animal Science, University of Tennessee, Knoxville, TN
| | - Jason K Smith
- Department of Animal Science, University of Tennessee, Knoxville, TN
| | | | | | - Gary E Bates
- Department of Plant Sciences, University of Tennessee, Knoxville, TN
| | | | - James L Klotz
- USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY
| | - Huihua Ji
- Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY
| | - Jack P Goodman
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY
| | - Amanda R Lee
- Department of Animal Science, University of Tennessee, Knoxville, TN
| | - J Marc Caldwell
- College of Veterinary Medicine, University of Tennessee, Knoxville, TN
| | - Phillip R Myer
- Department of Animal Science, University of Tennessee, Knoxville, TN
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23
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Melchior EA, Smith JK, Schneider LG, Mulliniks JT, Bates GE, McFarlane ZD, Flythe MD, Klotz JL, Goodman JP, Ji H, Myer PR. Effects of red clover isoflavones on tall fescue seed fermentation and microbial populations in vitro. PLoS One 2018; 13:e0201866. [PMID: 30335760 PMCID: PMC6193618 DOI: 10.1371/journal.pone.0201866] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/07/2018] [Indexed: 01/08/2023] Open
Abstract
Negative impacts of endophyte-infected Lolium arundinaceum (Darbyshire) (tall fescue) are responsible for over $2 billion in losses to livestock producers annually. While the influence of endophyte-infected tall fescue has been studied for decades, mitigation methods have not been clearly elucidated. Isoflavones found in Trifolium pratense (red clover) have been the subject of recent research regarding tall fescue toxicosis mitigation. Therefore, the aim of this study was to determine the effect of ergovaline and red clover isoflavones on rumen microbial populations, fiber degradation, and volatile fatty acids (VFA) in an in vitro system. Using a dose of 1.10 mg × L-1, endophyte-infected or endophyte-free tall fescue seed was added to ANKOM fiber bags with or without 2.19 mg of isoflavones in the form of a control, powder, or pulverized tablet, resulting in a 2 × 3 factorial arrangements of treatments. Measurements of pH, VFA, bacterial taxa, as well as the disappearance of neutral detergent fiber (aNDF), acid detergent fiber (ADF), and crude protein (CP) were taken after 48 h of incubation. aNDF disappearance values were significantly altered by seed type (P = 0.003) and isoflavone treatment (P = 0.005), and ADF disappearance values were significantly different in a seed × isoflavone treatment interaction (P ≤ 0.05). A seed × isoflavone treatment interaction was also observed with respect to CP disappearance (P ≤ 0.05). Eighteen bacterial taxa were significantly altered by seed × isoflavone treatment interaction groups (P ≤ 0.05), eight bacterial taxa were increased by isoflavones (P ≤ 0.05), and ten bacterial taxa were altered by seed type (P ≤ 0.05). Due to the beneficial effect of isoflavones on tall fescue seed fiber degradation, these compounds may be viable options for mitigating fescue toxicosis. Further research should be conducted to determine physiological implications as well as microbiological changes in vivo.
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Affiliation(s)
- Emily A. Melchior
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Jason K. Smith
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Liesel G. Schneider
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - J. Travis Mulliniks
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Gary E. Bates
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Zachary D. McFarlane
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
| | - Michael D. Flythe
- USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY, United States of America
| | - James L. Klotz
- USDA-ARS, Forage-Animal Production Research Unit, Lexington, KY, United States of America
| | - Jack P. Goodman
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, United States of America
| | - Huihua Ji
- College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, United States of America
| | - Phillip R. Myer
- Department of Animal Sciences, University of Tennessee, Knoxville, TN, United States of America
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24
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Melchior EA, Myer PR. Fescue toxicosis and its influence on the rumen microbiome: mitigation of production losses through clover isoflavones. JOURNAL OF APPLIED ANIMAL RESEARCH 2018. [DOI: 10.1080/09712119.2018.1496920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Emily A. Melchior
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, USA
| | - Phillip R. Myer
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, USA
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Backus WM, Waller JC, Bates GE, Harper CA, Saxton A, McIntosh DW, Birckhead J, Keyser PD. Management of native warm-season grasses for beef cattle and biomass production in the Mid-South USA. J Anim Sci 2017; 95:3143-3153. [PMID: 28727080 DOI: 10.2527/jas.2017.1488] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Native grasses, such as switchgrass (SG; L.), big bluestem (BB; Vitman), indiangrass (IG; Nash), and eastern gamagrass (EG; [L.] L.) may be capable of providing desirable summer forage for cattle as well as a source of biomass for renewable energy. To evaluate that potential, experiments were conducted at 2 locations in Tennessee comparing weaned beef () steers (268 ± 25 kg initial BW) during early-season grazing (Early; 30 d, typically corresponding to May, followed by postdormancy biomass harvest) and full-season grazing (Full, mean duration = 98 d). For Exp. 1, which compared SG, a blend of BB and IG (BBIG), and EG, ADG was greater ( < 0.05) for BBIG (1.02 kg/d) than SG (0.85 kg/d), and both were greater ( < 0.05) than EG (0.66 kg/d). Grazing days for SG and EG were similar (389 and 423 animal unit days [AUD]/ha, respectively) and exceeded ( < 0.05) that of BBIG (233 AUD/ha) during Full. In Exp. 2 (SG and BBIG only), rates of gain were comparable to that of Exp. 1, but AUD were 425 (SG) and 299 (BBIG) AUD/ha. Such rates of gain and grazing days indicate that these grasses can provide desirable summer forage for growing cattle. Early produced 211 to 324 kg BW gain/ha, depending on experiment and forage, followed by dormant-season harvests of 7.5 to 10.5 Mg/ha of biomass, indicating a potential for beef cattle forage and biomass production on the same land resource. Native grasses provided productive summer pasture and good rates of gain on growing cattle and could contribute to forage programs, especially where cool-season grasses currently predominate.
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Anthropogenic disturbances are key to maintaining the biodiversity of grasslands. Sci Rep 2016; 6:22132. [PMID: 26903041 PMCID: PMC4763272 DOI: 10.1038/srep22132] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 02/02/2016] [Indexed: 11/22/2022] Open
Abstract
Although anthropogenic disturbances are often perceived as detrimental to plant biodiversity, the relationship between biodiversity and disturbance remains unclear. Opinions diverge on how natural diversity is generated and maintained. We conducted a large-scale investigation of a temperate grassland system in Inner Mongolia and assessed the richness-disturbance relationship using grazing intensity, the primary anthropogenic disturbance in the region. Vascular plant-species richness peaked at an intermediate level of anthropogenic disturbance. Our results support the Intermediate Disturbance Hypothesis, which provides a valid and useful measure of biodiversity at a metacommunity scale, indicating that anthropogenic disturbances are necessary to conserve the biodiversity of grassland systems.
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Scaglia G, Beck P, Poore MH, Lehmkuhler J. BILL E. KUNKLE INTERDISCIPLINARY BEEF SYMPOSIUM: Tall fescue toxicosis update. J Anim Sci 2015; 93:5485-6. [PMID: 26641157 DOI: 10.2527/jas.2015-9892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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