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Cowan VE, Neumann A, McKinnon J, Blakley BR, Grusie TJ, Singh J. Arterial Responses to Acute Low-Level Ergot Exposure in Hereford Cows. Front Vet Sci 2018; 5:240. [PMID: 30386784 PMCID: PMC6198079 DOI: 10.3389/fvets.2018.00240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 09/12/2018] [Indexed: 11/13/2022] Open
Abstract
Ergot alkaloids are toxic secondary metabolites produced by the fungus Claviceps purpurea that contaminate cereal grains. Current Canadian standards allow 2 to 3 parts per million of ergot alkaloids in animal feed. The purpose of this study was to determine whether hemodynamic parameters were altered when beef cows were fed permissible levels of ergot alkaloids (i.e., <3 ppm) on a short-term basis. A dose-response relationship between ergot alkaloid concentration and hemodynamic changes in caudal (coccygeal), median sacral, and internal iliac arteries was hypothesized. Beef cows were randomly allocated to: Control (<15 μg total ergot alkaloids/kg dry matter), Low (132 μg/kg), Medium (529 μg/kg), and High (2115 μg/kg) groups (n = 4 per group). Animals were fed 8.8 kg of dry matter daily for 4 days (pre-treatment), 7 days (treatment), and 4 days (post-treatment). The caudal, median sacral, and internal iliac arteries were examined daily using ultrasonography in B-mode and Doppler (color and spectral) mode and hemodynamics endpoints were analyzed by repeated measures mixed model analyses. Caudal artery diameter decreased in the Medium (p = 0.004) and High (p < 0.001) groups compared to pre-treatment values and the pulsatility index increased (p ≤ 0.033) in all ergot treatments during the post-exposure period compared to the Control group. Blood volume per pulse (mL) and blood flow (mL/min) through the caudal artery during the treatment period were reduced in the Medium (-1.0 mL reduction; p ≤ 0.004) and High (-1.1 mL p ≤ 0.006) groups compared to pre-treatment values. The median sacral artery diameter decreased in the Medium (p = 0.006) and High (p = 0.017) treatments compared to the Control group. No differences were detected in any hemodynamic endpoints for the internal iliac artery except changes in pulse rate (p = 0.011). There was no treatment (p > 0.554) or Treatment*Time interaction (p > 0.471) for plasma prolactin concentration or body temperature. In conclusion, alterations in caudal artery hemodynamics were detected when cows were fed 529 and 2115 μg ergot alkaloids per kg dry matter per day for 1 week. The caudal artery was more sensitive to ergot alkaloids than the median sacral and internal iliac arteries. Our results partially support the hypothesis of a dose-response effect of ergot alkaloids in feed on hemodynamics.
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Affiliation(s)
- Vanessa Elizabeth Cowan
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.,Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Alex Neumann
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - John McKinnon
- Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Barry Raymond Blakley
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada.,Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Taylor Jayne Grusie
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jaswant Singh
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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Gorewit RC, Svennersten K, Butler WR, Uvnäs-Moberg K. Endocrine responses in cows milked by hand and machine. J Dairy Sci 1992; 75:443-8. [PMID: 1560139 DOI: 10.3168/jds.s0022-0302(92)77780-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Plasma concentrations of oxytocin, prolactin, and cortisol were compared in five Swedish Red and White cows milked by hand versus machine. Cows were divided into two groups. One group was hand-milked; the other group was machine-milked. Treatments were switched every other day. The experiment was carried out for 6 d. Blood samples were taken prior to, during, and after milking and were assayed for hormones. More oxytocin and prolactin were released in hand-milked cows. There were no significant diurnal differences between the total amount of oxytocin released for the different treatments, but prolactin tended to be higher during hand-milking in the evening than in the morning milking. Cortisol concentrations were greater during hand-milking than during machine-milking. There were no significant treatment differences with regard to the total amount of cortisol released. During morning milking, cortisol concentrations were higher during hand-milking than during machine-milking. Our data show that hand-milking results in a pronounced and prolonged release of oxytocin and prolactin.
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Affiliation(s)
- R C Gorewit
- Department of Animal Science, New York State College of Agriculture and Life Science, Cornell University, Ithaca
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Madej A, Edqvist LE, Kindahl H, Ekbohm G. Circadian rhythm of plasma prolactin in heifers. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1985; 32:419-27. [PMID: 3927629 DOI: 10.1111/j.1439-0442.1985.tb01958.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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