Circulating lipoprotein cholesterol and progesterone in postpartum and early gestational mares fed a control or fat-supplemented diet /
Eighteen pregnant Quarter Horse and 'Moroughbred mares were fed a control or 12% fat-supplemented diet (beef tarow stabilized with .025% ethoxyquin) beginning 2 wk prior to their predicted foaling dates. Mares were maintained on these diets through foaling and until d 50 of pregnancy. Serum co...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1996.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=743266561&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Eighteen pregnant Quarter Horse and 'Moroughbred mares were fed a control or 12% fat-supplemented diet (beef tarow stabilized with .025% ethoxyquin) beginning 2 wk prior to their predicted foaling dates. Mares were maintained on these diets through foaling and until d 50 of pregnancy. Serum concentrations of total cholesterol (TC), HDL-, LDL- and VLDL-cholesterol and progesterone were determined to test the hypothesis that the high-fat diet would increase serum cholesterol and progesterone concentrations in fat- supplemented mares. At wk 2 and beyond, fat-supplemented mares had higher TC concentrations (P=.01194) than control mares (controls: 4-18% below baseline; fat-supplemented: 13 35% above baseline). High-density lipoprotein cholesterol was also higher in fatsupplemented mares (P=.0390); deviations from baseline were similar to those observed with TC (fat-supplemented: 126-140% of baseline), though slight increases above baseline were observed in the controls (102- 120% of basal). Dietary fat supplementation increased LDL - chol concentrations above baseline at most sampling times in fat-fed mares (57-160% of baseline) in contrast to consistent decreases in control mares (23-68% of baseline), but variability in the LDL-cholesterol data prevented detection of significant treatment effects. No effect of diet was observed on VLDL-cholesterol. Diet had no effect on pregnancy rates, cycles per conception, foal or mare weigh@ or number of days from parturition to foal heat ovulation. However, days to the second postpartum ovulation in mares not conceiving on their first breeding were greater in the controls (P=.0129). Most importantly, increased TC and HDL, cholesterol in the fat-supplemented group had no detectable impact on progesterone concentration following ovulation compared to controls. It appears, however, that progesterone concentrations may be influenced by age of the mare. While the experimental design did not allow this hypothesis to be tested, when the data set was estricted to mares >10 y of age, progesterone concentrations were increased in fat- supplemented mares. Tlus, it is premature to reject our hypothesis that increased progesterone concentration can result from increased serum TC or HDL-cholesterol concentrations. The potential still exists that dietary manipulation of lipid status could have implications for mares in which low postovulatory progesterone concentration is caused by a lack of cholesterol to support steroidogenesis. |
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| Item Description: | Vita. "Major Subject: Animal Science". |
| Physical Description: | xiv, 128 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |