15-keto-13-14-dihydroprostaglandin-f2alpha and Body-Weight

The foal requires an active hypothalamo-pituitary-adrenal (HPA) axis for organ maturation and post natal survival. Prenatal administration of synthetic glucocorticoids may provide an effective method for inducing fetal maturation safely in the mare.. To determine whether dexamethasone administered to late pregnant mares: 1) will induce fetal maturation and precocious delivery; 2) is safe to use and 3) to identify endocrine responses in the mare and foal.. Pregnant Thoroughbred mares received either 100 mg dexamethasone i.m. (treated n = 5) or 50 ml saline i.m. (control n = 5) at 315, 316 and 317 days of gestation. Plasma progestagens, cortisol and prostaglandin F(2α) metabolite (PGFM) concentrations were measured before and after treatment. The foals were weighed, the crown-rump length (CRL) measured and an adrenal stimulation test performed on Day 1.. Dexamethasone significantly (P<0.01) reduced gestation length in treated mares without apparent adverse effects. Plasma progestagens increased (P<0.05), and cortisol and PGFM (P<0.05) decreased, following dexamethasone treatment compared with control mares. Foals were clinically mature but those from dexamethasone treated mares had reduced (P<0.05) CRL, but not bodyweights, compared with controls. Their cortisol concentrations increased following exogenous adrenocorticotrophic hormone stimulation but 2 foals from dexamethasone treated mares showed evidence of adrenal suppression.. Dexamethasone stimulates precocious fetal maturation and delivery in healthy late pregnant mares. However, fetal HPA activity may be suppressed.. Dexamethasone treatment could be used to improve foal viability in mares at risk of preterm delivery. The endocrine effects of such a therapy must be evaluated before clinical intervention with glucocorticoids can be recommended.

Topics: Animals; Animals, Newborn; Body Weight; Crown-Rump Length; Dexamethasone; Dinoprost; Female; Glucocorticoids; Horses; Hydrocortisone; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Pregnancy; Progestins

Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of aging. We investigated the effects of supplementation with vitamin E on lipid peroxidation in rats. Both free radical-induced nonenzymatic- and cyclooxygenase-catalyzed enzymatic lipid peroxidation were investigated by measuring the levels of F(2)-isoprostanes (8-iso-PGF(2alpha)) and PGF(2alpha)-metabolite (15-K-DH-PGF(2alpha)), respectively, in blood, urine and liver. Samples were collected from control rats (n = 6) and from rats supplemented with vitamin E in the diet for 3 wk (n = 8, 20 g/kg diet of DL-alpha-tocopherol hydrogen succinate). Plasma alpha-tocopherol concentration and antioxidative capacity were greater in the vitamin E-supplemented rats than in the control rats (17.9 +/- 1.7 vs. 50.4 +/- 10.4 micromol/L, P < 0.001 and 181 +/- 6 vs. 275 +/- 27 micromol/L trolox equivalents, P < 0.001). Urine 8-iso-PGF(2alpha) tended to be lower in the vitamin E-supplemented rats (0.72 +/- 0.40 vs. 0.34 +/- 0.19 nmol/mmol creatinine, P = 0.056). Urine 15-K-DH-PGF(2alpha) was lower due to vitamin E supplementation (0.97 +/- 0.38 vs. 0.56 +/- 0. 21 nmol/mmol creatinine, P < 0.05), as was liver-free 8-iso-PGF(2alpha) concentration (0.47 +/- 0.11 vs. 0.18 +/- 0.04 nmol/g, P < 0.001). Supplementation with vitamin E did not affect plasma 8-iso-PGF(2alpha) or 15-K-DH-PGF(2alpha) concentrations, liver total 8-iso-PGF(2alpha) or plasma malondialdehyde levels. Thus, vitamin E supplementation reduced urine basal levels of biomarkers of both nonenzymatic and enzymatic lipid peroxidation. In liver, vitamin E reduced the basal level of free 8-iso-PGF(2alpha) but not total 8-iso-PGF(2alpha).

Topics: Animals; Body Weight; Chromatography, High Pressure Liquid; Diet; Dinoprost; F2-Isoprostanes; Lipid Peroxidation; Liver; Male; Malondialdehyde; Oxytocics; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Vasoconstrictor Agents; Vitamin E

Forty pluriparous (M) and 20 primiparous (P) suckled Brahman cows were used to evaluate the effect of aspirin and parity on plasma 13,14-dihydro-15-keto-prostaglandin F2alpha (PGFM) and progesterone (P4) concentrations and some reproductive parameters. On Day 7 after calving (PP), the cows were allocated within parity into 2 groups: the aspirin group received concentrate containing aspirin at a rate of 100 mg/kg of body weight every 12 h until Day 13 PP; and the control received concentrate every 12 h for the same interval. Blood samples were collected after first and last aspirin feeding and daily from Day 1 PP to Day 6 PP and from Day 14 PP to Day 21 PP, twice daily from Day 7 PP to Day 13 PP, and weekly until first non-return to estrus. Plasma salicylate concentrations in the aspirin group cows were affected by parity (P < 0.01) and time after feeding (P < 0.0001). P cows showed higher plasma salicylate concentrations with a later peak and slower decrease than M cows. Aspirin-treated P cows had longer PP intervals than either control P, control M, or aspirin-treated M cows. Cows receiving aspirin had a lower pregnancy rate, an increased incidence of abnormal estrous cycles, and a decline in the presence of corpora lutea after estrus. Cows that formed a corpora lutea and had received aspirin had higher P4 release between Day 6 and 14 after estrus. Aspirin-treated cows that did not form corpora lutea had lower P4 release between Days 9 and 14 after estrus. A treatment by parity interaction affected mean PGFM proportions (P < 0.01) during the treatment period. Aspirin-fed P cows increased PGFM release as measured by mean proportion of Day 6 PP values. Aspirin-fed M cows showed a decrease in mean PGFM proportions. Aspirin feeding during the early PP showed different effects on some reproductive parameters in P and M Brahman cows, indicating differences in PP physiology between parities.

Topics: Animals; Aspirin; Body Weight; Cattle; Dinoprost; Estrus; Female; Parity; Postpartum Period; Pregnancy; Pregnancy, Animal; Progesterone; Salicylates; Sex Factors

Plasma concentrations of progesterone, oestradiol-17beta, oestrone, oestrone sulphate and PGFM have been measured daily during the first peri-partum period of 45 Hereford x Friesian heifers bred at 11 months of age. Anatomical measurements of dam and calf were also recorded. Twelve of the calvings were scored easy, 33 difficult. Each of five models (fitted by linear logistic regression) relating difficulty of calving to the hormonal and anatomical measurements, predicts with at least 94% accuracy the calving score (easy or difficult) among the calvings. The models predict that increases of progesterone concentration on the day before calving, of oestrone sulphate concentration on the day after calving and of heifer heart girth decrease the odds of difficult calving, whereas increases of heifer body length and of calf head circumference increase the odds of difficult calving.

Topics: Animal Feed; Animals; Animals, Newborn; Body Weight; Cattle; Cattle Diseases; Dinoprost; Dystocia; Estradiol; Estrogens; Estrogens, Conjugated (USP); Estrone; Female; Insemination, Artificial; Labor, Obstetric; Logistic Models; Male; Multivariate Analysis; Numerical Analysis, Computer-Assisted; Pregnancy; Progesterone; Radioimmunoassay

The response to Claviceps purpurea sclerotia administration in pregnant goats was examined in terms of changes in the levels of plasma hormones, the development of pregnancy and kid production. Six treated goats were each given 15 mg milled sclerotia (i.e. 0.105 mg ergotamine) per kilogram live weight twice daily via a stomach tube from days 98 +/- 2 to 107 +/- 2 of gestation. Seven control goats were given water twice daily via a stomach tube during the same period of gestation. The goats were observed for clinical signs of disease, rectal temperatures and live weights were recorded and the condition of the foetuses was monitored by real-time ultrasonography. All control goats delivered live kids. In the treated group two goats aborted 33 and 47 days, respectively, after the start of the administration period, two goats each delivered one normal and one weak kid, and the two remaining goats delivered apparently normal kids. All six treated goats became depressed and had poor appetite during the period of sclerotia administration. Rectal temperatures were significantly increased and live weight changes significantly decreased in the animals in the treated group compared to the control group during the period of C. purpurea administration. Ultrasound examination revealed that foetal deaths occurred between 1 and 42 days before abortion or birth. The appearance of the aborted foetuses varied from fresh to mummified, depending on the number of days between foetal death and expulsion. Microbiological and serological investigations revealed no infectious causes of reproductive failure. The level of 15-ketodihydro-PGF2 alpha was high in goats that aborted following administration of C. purpurea compared with the level in control goats. The oestrone sulphate level did not increase before abortion in the treated goats as in the controls before parturition. There were also changes in these hormones in the four treated goats that delivered live kids, but the changes were considerably smaller. These findings indicate that the endocrine foetal-placental function was disturbed, probably due to injury caused by the C. purpurea toxin ergotamine in the placenta and foetus.

Topics: Abortion, Veterinary; Adrenergic alpha-Agonists; Animals; Body Weight; Claviceps; Dinoprost; Endocrine Glands; Enzyme-Linked Immunosorbent Assay; Ergotamine; Estrone; Female; Fetal Death; Goats; Heart Rate, Fetal; Placenta; Pregnancy; Pregnancy Outcome; Progesterone; Toxoplasma; Toxoplasmosis, Animal

Brahman cows were used to evaluate the effects of postpartum nutrition and suckling on reproductive and calf performance. Cows received high or low TDN and once-daily or unrestricted suckling. High TDN (H; 111% of NRC recommendation) cows received a 75% corn: 25% soybean meal diet. Low TDN (L; 93% of NRC recommendation) cows received no concentrates. Once-daily suckled (restricted, R) cows nursed calves for 30 min/d starting at d 21 after calving. In the unrestricted (U) suckling groups, calves had continuous access to cows. By 2 wk of suckling restriction, more (P < .01) R than U cows had progesterone concentrations of > or = .7 ng/mL (55 vs 0%) and more (P < .05) HR than LR cows had progesterone concentrations > or = .7 ng/mL (70 vs 40%). All groups had increases in progesterone and 13,14-dihydro-15-keto-prostaglandin F2 alpha before estrus. The interval to first estrus was shorter (P < .01) for R than for U cows (42 vs 65 d). By d 42 postpartum, more (P < .01) R than U cows exhibited estrus (67 vs 0%), and more (P < .05) HR than LR cows exhibited estrus (89 vs 44%). Calving interval was shorter (P < .01) for R than for U cows (361 vs 395 d). Initial ADG were lower (P < .01) for R than for U calves (.02 vs .69 kg), but weaning weights were similar. Once-daily suckling permitted ovarian activity, hastened return to estrus, and reduced calving interval without reducing weaning weights. Increased postpartum energy intake enhanced the response to restricted suckling.

Topics: Anestrus; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Cattle; Dinoprost; Female; Fertility; Lactation; Male; Parity; Pregnancy; Progesterone; Random Allocation