Induction of Parturition with Aglepristone in the Majorera Goat

Induction of parturition in a large number of pregnant dairy goats and its benefits as a management tool in a commercial scale goat operation

At LFB USA, Inc., transgenic goats are utilized for the production of recombinant human protein therapeutics in their milk through the rPRO™ Technology platform. This retrospective analysis and report describes the results of induced parturition and its use as a management tool in this large herd of dairy goats. Over a three-year period, 342 does received pronuclear microinjected (MI) embryos transferred into the oviductal lumen via midline laparotomy (day 1). To initiate the induction process, does were given intramuscular injections (IM) of 10 mg each of prostaglandin (Lutalyse®) and dexamethasone to induce parturition on days 144-148 of pregnancy. Mean and Standard Deviation (±SD) time to parturition was 36.7 (±6.5) hours. Does were given these injections at 4pm on Sundays with an expected kidding time of late Monday into Tuesday morning. Of the 342 does, 333 or 97% had kidded by 3pm the following Tuesday, and 313 or 91% kidded in the 18 h between 9pm Monday and 3pm on Tuesday or between 29 and 47 h post induction. By the end of Tuesday, most kids had received colostrum and were transferred to the nursery. The incidences of kid mortality and retained placenta were 2.5% and 1.5%, respectively, clearly achieving a priority at this commercial operation for generating a high percentage of live kids (97.5%) of marked value being produced. The use of induced parturition allowed this large dairy operation to designate two 9-h time blocks in which to concentrate parturition times within the herd. This facilitated strategic scheduling to optimize availability of staff, in order to assist with parturition, separate kids from the dam at birth, and ensure adequate and prompt feeding of colostrum. Predicting the time of kidding in this way can serve as an effective management tool, especially to help reduce kid mortality and prevent disease spread by restricting suckling of colostrum.

Progesterone receptor blockers: historical perspective, mode of function and insights into clinical and scientific applications

Antigestagens (antiprogestins) are functional competitors of progesterone (P4) that prevent P4 from mediating its biological functions either by suppressing its production or blocking its function. Among the latter are progesterone antagonists, competitors of P4 binding to its nuclear receptor PGR, which have found application in both human and veterinary medicine, in particular in small animal practice for the prevention of nidation and the interruption of pregnancy. Depending on their mode of action, progesterone receptor antagonists can be divided into 2 classes. Class I antagonists bind to the PGR but fail to induce its binding to promoters of target genes (competitive inhibitors). Class II antigestagens, including aglepristone used in veterinary medicine, bind to the PGR, activate its association with a promoter, but interfere with the downstream signalling cascades, e. g., by recruiting transcriptional repressors. They act thereby as transdominant repressors exerting negative effects on target gene expression. Importantly for experimental sciences, as active antagonists, class II antagonists do not require the presence of the natural ligand for their action. Besides their clinical application, antigestagens are used in research for investigating P4-dependent physiological and pathological processes. Here an overview of the history and the current usage of progesterone receptor antagonists in veterinary medicine and research is presented.

Comparison of the endocrinological and immunological results of different induction of parturition methods in ewes

OBJECTIVE

This study aimed to compare different induction of partu -rition (IP) methods in terms of endocrinological and immunological parameters in ewes and lambs.

MATERIALS AND METHODS

A total of 24 ewes and their respective 24 lambs were studied. Groups of six ewes were induced on the 138th day: groups I (control), II (dexamethasone), III (aglepristone) and IV (aglepristone + dexamethasone). Blood samples were taken from the ewes from IP to 2 days postpartum at 12-hour intervals for the prolactin and oxytocin analyses. Colostrum and blood samples were collected from the lambs at 0, 12, 24, 36 and 48 hours for the IgG analysis. The prolactin, oxytocin and IgG levels were measured by ELISA.

RESULTS

A significant difference was found in prolactin levels in all groups and in the colostral IgG level in group IV with respect to the sampling time. Additionally, a significant difference in prolactin level was found at 24 hours postpartum between group IV and groups I and III. A significant difference in the colostral IgG level was determined at 24 hours after parturition between group III and the other groups and at 48 hours after parturition between groups II and III. A positive and significant correlation between the colostral and serum IgG levels of the lambs was found at 24 hours in groups I and II.

CONCLUSION AND CLINICAL RELEVANCE

Although varying individual results were found within the groups, the endocrinological and immunological results did not suggest any superiority among the IP methods. Considering the presented study results, a single dose of aglepristone may be used alone or in combination with dexamethasone for I P.

Uterine and placental expression of HPGD in cows during pregnancy and release of fetal membranes

15-Hydroxyprostaglandin dehydrogenase (HPGD) plays a key role in prostaglandins (PGs) catabolism. Its expression and activity appear to be regulated by progesterone (P4). We investigated the HPGD mRNA-expression and protein localization in placentomes and interplacental uterine sites throughout gestation (Study I), and after fetal membranes retention (RFM) compared with normally delivered fetal membranes (DFM) (Study II). Furthermore, we analyzed the influence of aglepristone (AP), dexamethasone (GC) or cloprostenol (CP), on HPGD expression in bovine placentomes (Study III). Tissues from late gestation (D272) and at normal term (NT) served as controls. HPGD was highest in all sites at the beginning of pregnancy and at (NT). Following induced parturition HPGD was lower after (AP) and (GC) compared with (NT), and was similar in RFM and DFM. Placentomes stained primarily in fetal compartments; interplacentomal signals were observed in endometrial glandular and luminal epithelium. Results indicate that HPGD may play a role during establishment and termination of gestation.