dinoprost and tiaprost

In Argentina, most dairy cows with endometritis are treated with prostaglandin (PGF(2alpha) or its analogs) and insemination is withheld until there are no signs of endometritis. The objective of the present study was to evaluate if this method of managing endometritis enhances reproductive performance. Three experiments were conducted over 4 years in a large farm in the west of Buenos Aires province. In Experiment 1, half of the cows diagnosed with endometritis (>1.5-fold difference in diameter of uterine horns, as determined by rectal palpation) received standard endometritis management (treatment with tiaprost, a PGF(2alpha) analog, rectal palpation every 20 days, and withholding of AI until endometritis apparently resolved) and the other half was untreated, with AI at the first estrus after the voluntary waiting period. Untreated cows were inseminated and conceived 20 days earlier than treated cows, and the pregnancy rate by Day 90 postpartum was higher in the untreated group. In Experiment 2, cows with endometritis were divided into four groups according to the severity of symptoms; within each group, cows were allocated to treatment or control, as in Experiment 1. Although first service conception rate decreased as endometritis severity increased, reproductive performance in treated versus control cows was similar to that of Experiment 1 (with no interaction due to degree of endometritis). Re-evaluation of the treated cow (to confirm uterine "normality") may have been responsible for the delay in conception in both experiments. The objective of Experiment 3 was to determine the effects of tiaprost treatment on clinically normal postpartum cows (no evidence of endometritis). Tiaprost treatment reduced the interval from calving to conception in multiparous cows, but it delayed conception and reduced the conception rate in primiparous cows. In conclusion, treatment with tiaprost impaired reproductive performance in primiparous cows (in the absence of endometritis). Furthermore, the standard treatment for endometritis (treatment with a prostaglandin analog and withholding insemination until clinical signs abated) impaired reproductive performance and increased costs.

Topics: Animals; Argentina; Cattle; Cattle Diseases; Dinoprost; Endometritis; Estrus; Female; Fertilization; Insemination, Artificial; Linear Models; Palpation; Parity; Pregnancy; Prostaglandins F, Synthetic; Rectum; Reproduction; Thiophenes; Time Factors; Uterus

Ovsynch protocols are used to increase service rate and decrease days open and cullings for infertility. Recent reports have indicated better results after Ovsynch in primiparous than in older cows. However, this was not observed in all investigations on the subject. The objective of the study was to evaluate differences between primiparous and multiparous cows after synchronization of ovulation with an Ovsynch protocol in six trials. A total of 1584 cows (583 primiparous and 1001 multiparous cows, respectively) on three dairy farms were synchronized with an Ovsynch protocol consisting of a GnRH-analogue at Days 0 and 9, and a prostaglandin F(2alpha) analogue on Day 7. AI was carried out in all cows 16-20 h after the last treatment. Cows were categorized into primiparous and multiparous cows for analysis. Conception rate (CR) to timed AI, to further AI, overall conception rate and proportion of cows pregnant by 200 days in milk were compared between the age groups. Finally, two logistic regression models were calculated with conception to first service and conception by 200 DIM as the outcome variables. Independent variables were trial (categorical) and age group (primiparous versus multiparous). Conception rates to TAI were higher in primiparous than in older cows (37.9% versus 31.6%, P=0.015). Likewise pregnancy rates by 200 DIM were higher in primiparous cows (81.8% versus 75.4%, P=0.003). However, the extent of the difference varied between trials. Results indicate that Ovsynch protocols are more effective in primiparous than in older cows.

Topics: Aging; Animals; Buserelin; Cattle; Dinoprost; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Insemination, Artificial; Logistic Models; Ovulation Induction; Parity; Pregnancy; Prostaglandins F, Synthetic; Thiophenes

The effects of luteolytic doses of PGF2 alpha (25 mg Dinoprost) and its synthetic analogues Cloprostenol (500 micrograms), Luprostiol (15 mg) and Tiaprost (525 micrograms) on bovine myometrial activity were investigated using a miniature pressure transducer placed in one uterine horn. The compounds were administered intravenously to 4 lactating cyclic cows at diestrus, proestrus, estrus and metestrus. Intrauterine pressure changes were assessed by computerized planimetry of the pressure tracings 30 minutes before and 60 minutes after treatment. Baseline intrauterine pressure was set at zero and treatment effects were expressed as percent change from an equivalent control period (= 100%). Following administration of Dinoprost there was a significant increase of uterine contractility in diestrus (515%), proestrus (198%) and metestrus (256%), but not in estrus. In comparison to PGF2 alpha the analogues Luprostiol and Tiaprost were less effective (Luprostiol: 195% and 154% in diestrus and proestrus resp., Tiaprost: 215% during diestrus), while Cloprostenol did not cause a significant change of intrauterine pressure in any stage of the estrous cycle. The results indicate that the myotonic effects which F2 alpha-prostaglandins exert on the uterus of cycling cows is affected both by the type of prostaglandin and the stage of the estrous cycle.

Topics: Animals; Cattle; Cloprostenol; Dinoprost; Estrus; Female; Luteolytic Agents; Prostaglandins F, Synthetic; Thiophenes; Uterine Contraction

Topics: Animals; Blood Pressure; Bronchi; Cloprostenol; Dinoprost; Guinea Pigs; In Vitro Techniques; Muscle, Smooth; Platelet Aggregation; Prostaglandins F; Prostaglandins F, Synthetic; Rabbits; Rats; Thiophenes