Colostrum feeding and its effects on serum cortisol, thyroxine, immunoglobin G and cytosolic glucocorticoid receptors in skeletal muscle in the bovine neonate
| dc.contributor.author | Waggoner, David Kent | en |
| dc.contributor.department | Animal Science | en |
| dc.date.accessioned | 2014-03-14T21:40:54Z | en |
| dc.date.adate | 2010-07-21 | en |
| dc.date.available | 2014-03-14T21:40:54Z | en |
| dc.date.issued | 1987 | en |
| dc.date.rdate | 2010-07-21 | en |
| dc.date.sdate | 2010-07-21 | en |
| dc.description.abstract | The effect of feeding colostrum or milk to newborn calves on serum cortisol, thyroxine and immunoglobulin G was investigated. Twenty-four calves (12 males and 12 females) were obtained immediately postpartum and randomly assigned to one of two rations after being blocked by breed and sex. Both rations were force-fed at birth, 12, 24 and 36 h postpartum. Blood sampling was performed at 0 time, 1, 2, 3, 4, 6 and 12 h postfeeding with this regime followed for a 48 h period (4 feedings). The average serum cortisol concentration was highest at birth, 221.9 and 245.6 ng/ml for colostrum and milk-fed calves, respectively. Cortisol levels between treatments were different (P<.05) at 2, 3, 12, 14, 18, 24, 37 and 48 h postpartum. The sex of the calf did not affect the mean cortisol concentrations. No treatment difference was observed for serum thyroxine. A sex difference was observed with the female calves exhibiting higher average thyroxine concentrations over the entire trial. A reduction in thyroxine concentration occurred with time (P<.001) as mean concentrations peaked at 4 h postpartum (22.1 μg/dl) and declined to 10.6 μg/dl by 48 h postpartum. Both treatment groups were born with similar serum immunoglobulin G levels (~0.7 mg/ml). However, at approximately 4 h postpartum, the colostrum-fed calves acquired an increase (P<.001) in serum immunoglobulin G, peaking at 24 h postpartum (26.83 mg/ml) and remaining much higher throughout the entire trial. There was a treatment difference (P<.001) between the two groups following the 4 h sample. Muscle samples (20-30g) were surgically removed from the right semitendinosus at 36 h postpartum from 14 neonatal beef calves (male and female), homogenized, and centrifuged at 105,000 x g at 4 C for 60 min. The supernatant (cytosol) was harvested and receptor quantitation, binding kinetics and ligand specificity assays were performed via [1,2,4,³H] dexamethasone. There were no binding differences between the colostrum and milk-fed calves' muscle samples. The average protein content of the muscle cytosol fraction was 50.82 mg/ml. The binding component displayed a high apparent equilibrium dissociation constant for the binding of [³H] dexamethasone (K<sub> d </sub> = 2.34x10 ⁻⁸ ). The apparent maximum number of binding sites determined from Scatchard plots was approximately 37.61 fmol/mg of protein in the case of the dexamethasone receptor. Maximum binding appeared to reached between 16 and 24 h (48.5 and 48.2 %, respectively). Competition assays indicated all of the ligands tested had an affinity for the glucocorticoid receptor. The percent of specific binding for each was: dexamethasone (66+/-14), corticosterone (52+/-10), cortisol (58+/-13), estradiol-17, beta (37+/-7), progesterone (29+/-9), testosterone (10+/-3), and triamcinolone (41+/-11). | en |
| dc.description.degree | Master of Science | en |
| dc.format.extent | vii, 144 leaves | en |
| dc.format.medium | BTD | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.other | etd-07212010-020156 | en |
| dc.identifier.sourceurl | http://scholar.lib.vt.edu/theses/available/etd-07212010-020156/ | en |
| dc.identifier.uri | http://hdl.handle.net/10919/43830 | en |
| dc.publisher | Virginia Tech | en |
| dc.relation.haspart | LD5655.V855_1987.W33.pdf | en |
| dc.relation.isformatof | OCLC# 16781727 | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject.lcc | LD5655.V855 1987.W33 | en |
| dc.subject.lcsh | Calves | en |
| dc.subject.lcsh | Glucocorticoids -- Receptors | en |
| dc.subject.lcsh | Hydrocortisone | en |
| dc.subject.lcsh | Veterinary immunology | en |
| dc.title | Colostrum feeding and its effects on serum cortisol, thyroxine, immunoglobin G and cytosolic glucocorticoid receptors in skeletal muscle in the bovine neonate | en |
| dc.type | Thesis | en |
| dc.type.dcmitype | Text | en |
| thesis.degree.discipline | Animal Science | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | masters | en |
| thesis.degree.name | Master of Science | en |
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