Effect of Different Forms of Prostaglandin F2? Analogues Administration on Hormonal Profile, Prostaglandin F2? Binding Rate and Reproductive Traits in Akkaraman Sheep During the Breeding Season

Abstract

Background: We also aimed to detect endogenous anti-prostaglandin F-2 alpha antibodies and the relationship between these antibodies and fertility parameters such as pregnancy rates after the use of PGF(2)alpha. Synchronization of estrus with the PGF(2)alpha is sometimes ineffective in sheep. This situation is to bring about due to the lack of a functional corpus luteum, given before day 5-6 of the estrous cycle. But, it can be suggested that the immunity developing for endogenous or exogenous PGF(2)alpha analogues or metabolites. Materials, Methods & Results: The efficacy of single dose prostaglandin F-2 alpha analogues such as dinoprost tromethamine, cloprostenol sodium and d-cloprostenol was studied in 60 nulliparous and multiparous Akkaraman sheep. The animals were grouped in three groups (n = 20). Each group was randomly divided into two subgroups comprising a minimum of 10 nulliparous and multiparous animals. All individual serum samples collected from one flock in Kayseri province of middle Anatolian Turkey, in the period from August 2009 to October 2009. The Animals were kept in free stall and indoors at night, and had access to grazing outdoors most of the day. Prostaglandin F-2 alpha was administered to the animals one week after the first estrus and blood samples were collected three times (at 0, 24(th) and 48(th) h after the injection). 10 mL blood was collected respectively via jugular venipuncture. The estrus cycle of each ewe was followed 4 times at a 6-h interval (to determine differences of estrus time between the groups) using teaser rams. The concentrations of progesterone and estradiol in the samples were measured using the commercial Enzyme-Linked Immunosorbent Assay (ELISA) kits. Furthermore, the presence of anti-prostaglandin F-2 alpha antibodies in these samples was detected by scintillation counter using radioactively-labeled [ 5,6,8,9,11,12,14,15(n)-H-3] PGF(2)alpha. There was a significant decrease in the progesterone levels in both nulliparous and multiparous animals, to which cloprostenol sodium was administered on the day of administration and after 24 and 48h, compared to other groups. There was no significant difference between the groups in terms of pregnancy rates. Anti-prostaglandin F-2 alpha antibodies were detected in all blood samples, although the levels were low. The binding rates for PGF(2)alpha in sera collected at the 48(th) hour after a single dose d-cloprostenol administration were lower than those on the day of injection in multiparous animals. However, it was considered that these antibodies did not have a sufficient level to affect parameters such as pregnancy rates in Akkaraman sheep. Discussion: However, it was found that the effects of three PGF(2)alpha analogues were not different in terms of pregnancy rates. It was also concluded in this study that anti-prostaglandin F-2 alpha antibodies did not show any effect on parameters such as pregnancy rates in Akkaraman sheep. In addition, it was concluded that it is required to perform further studies with more details related to the development of anti-prostaglandin F-2 alpha antibodies and their effect mechanism on fertility in Akkaraman sheep.