Abstract
Previously, we reported the effects of fescue toxicosis on developing Angus-cross steer growth, carcass, hepatic mRNA, and protein expression profiles of selected serum proteins, and blood clinical and chemical profiles, after summer-long grazing (85 days) of high endophyte (HE)- vs. low endophyte (LE)-infected fescue pastures. We now report the temporal development of acute, intermediate, and chronic responses of biochemical and clinical blood analytes determined at specified time intervals (period 1, day 0-36; period 2, day 37-58; and period 3, day 59-85). Throughout the trial, the alkaloid concentrations of the HE forage was consistently 19-25 times greater (P ≤ 0.002) than the concentration in the LE forage, and HE vs. LE steers had continuously lower (P ≤ 0.049) serum prolactin (85%), cholesterol (27%), and albumin (5%), but greater red blood cells (7%). The HE steers had decreased (P = 0.003) ADG only during period 1 (-0.05 vs. 0.4 kg/day). For period 1, HE steers had reduced (P = 0.090) numbers of eosinophils (55%) and lymphocytes (18%), serum triglyceride (27%), and an albumin/globulin ratio (9%), but an increased bilirubin concentration (20%). During period 2, serum LDH activities were 18% lower (P = 0.022) for HE vs. LE steers. During period 3, serum levels of ALP (32%), ALT (16%), AST (15%), creatine kinase (35%), glucose (10%), and LDH (23%) were lower (P ≤ 0.040) for HE steers. Correlation analysis of serum prolactin and other blood analytes revealed that triglycerides (P = 0.042) and creatinine (P = 0.021) were moderately correlated (r ≤ 0.433) with HE serum prolactin. In conclusion, three HE-induced blood analyte response patterns were identified: continually altered, initially altered, and subsequently "recovered," or altered only after long-term exposure. Blood analytes affected by length of grazing HE vs. LE forages were either not or poorly correlated with serum prolactin. These data reveal important, temporal, data about how young cattle respond to the challenge of consuming HE pasture.
Original language | English |
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Article number | 77 |
Journal | Frontiers in Veterinary Science |
Volume | 2 |
Issue number | DEC |
DOIs | |
State | Published - Dec 21 2015 |
Bibliographical note
Funding Information:This is publication No. 15-07-119 of the Kentucky Agricultural Experiment Station and is published with approval of the Director. This work is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Special Cooperative Agreement (JM) and Multistate project No. 1000591.
Publisher Copyright:
© 2015 Jackson, Lindemann, Boling and Matthews.
Keywords
- Blood cells
- Blood metabolites
- Cattle
- Ergot alkaloids
- Neotyphodium coenophialum
ASJC Scopus subject areas
- Veterinary (all)