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The aim of the present study was to compare the endometrial gene expression of epidermal growth factor receptor (EGFR), nodal growth differentiation factor (NODAL), prostaglandin-endoperoxide synthase 2 (PTGS2), oestrogen receptor 1 (ESR1) and progesterone receptor (PGR) in repeat breeder cows (RBC) and non-RBC during diestrus. Endometrial samples were collected by cytobrush technique and stored in RNA stabilizing solution at -20°C until RT-qPCR analysis. Differences in endometrial mRNA expression of selected genes were assessed by ANOVA and simple (r) and the partial correlations (rp) among selected genes were performed. Results demonstrated that mRNA expression of EGFR and NODAL were higher in RBC than in non-RBC (3 and 25-fold change, p < .01 and p < .01, respectively), while the mRNA expression of PTGS2 was lower (1.56-fold change, p < .01). Although there were no differences detected in the mRNA expression of ESR1 and PGR, there was a positive correlation between the expression of ESR1 and EGFR (0.84, p < .05) and a negative correlation between PGR and PTGS2 (-0.49, p < .05). In conclusion, the difference on the endometrial mRNA expression of the genes included in the study between RBC and non-RBC indicates a deregulation of important mechanisms that are vital to establish a successful pregnancy. Thus, the present study provides useful insight as a base for future studies to elucidate the causes of RBC.

The objective of this study was to evaluate the prevalence of clinical endometritis and its impact on reproductive performance in grazing dairy cattle in Argentina to compare data with previous reports from herds kept in confinement housing systems. A total of 243 Holstein dairy cows from three commercial dairy farms in Buenos Aires Province (Argentina) were examined for the signs of clinical endometritis 18-38 days postpartum (dpp) by external inspection and manual vaginal examination. Vaginal discharge was scored into the categories VDS 0 (transparent, clear mucus), VDS 1 (mucupurulent discharge), VDS 2 (purulent discharge) and VDS 3 (purulent discharge with fetid odour). Cows diagnosed with VDS 1 to VDS 3 were regarded as affected with clinical endometritis and cows with VDS 0 as free of clinical endometritis. All cows were re-examined 14 days later following the same examination protocol. Prevalence of clinical endometritis 18-38 dpp was 35% and decreased to 18% at re-examination. Cows with no palpable ovarian structures or periparturient disorders were at higher risk for clinical endometritis. Hazard for pregnancy was significantly lower in cows with purulent or fetid odour discharge compared with reference cows with no discharge (HR=0.49; p=0.01), resulting in a lower proportion of cows pregnant by 360 dpp (66% vs 78%). Furthermore, the number of services per pregnancy was higher for cows with clinical endometritis than for cows without clinical endometritis (4.4 vs 3.1; p=0.04). Cows with clinical endometritis were 1.6 times as likely to be culled as cows with no signs of clinical endometritis. In conclusion, the prevalence and the impact of clinical endometritis in a pasture-based, extensive dairy production system in Argentina were similar to previously published data from dairy farms with confinement production systems.

Gonadotropin-releasing hormone (GnRH) antagonists are particularly useful when a rapid inhibitory effect on the gonadal axis is required. The aim of this study was to test the efficacy and clinical safety of a low and high dose of the third generation GnRH antagonist, acyline, on pregnancy termination in female dogs. The effect of the antagonist on the progesterone (P(4)) serum concentration was also described. Twenty-one mid-pregnant bitches were randomly assigned to a single subcutaneous (SC) dose of a placebo (PLACE; n = 7), a low (ACY-L; 110 microg/kg; n = 6) or high (ACY-H; 330 microg/kg; n = 8) dose of acyline. The animals were followed up for 15 days. All ACY treated but no placebo-treated animals terminated their pregnancy by abortion (p0.01). The ACY-L and ACY-H groups interrupted their pregnancy 7 +/- 1.9 and 6.4 +/- 1.3 days after treatment, respectively (p = 0.7). A significant interaction between treatment and day was found (p0.01) for P(4) serum concentrations when PLACE was compared with both ACY groups. No difference was found for this hormone between both ACY groups (p0.05) where P(4) diminished throughout the study. The decreasing rate varied among animals and was closely related to the time of abortion when P(4) reached basal concentrations. In PLACE animals, gestation progressed normally and P(4) did not change throughout the study (p0.05). None of the bitches presented side effects. It was concluded that acyline safely terminated mid-pregnancy by permanently decreasing P(4) serum concentrations.

The aim of this study was to asses the variation in the morphology of the seminal epithelium in relation to natural photoperiod in male cats. Tom cats (n = 240) were castrated every other week throughout the year. Each testis was fixed in Bouin's solution and cut into sections. The percentage of tubules with round spermatids (RS), elongated spermatids (ES), tailed spermatids (TS), mature spermatids (MS) and the number of Sertoli cells (SC) and Leydig cells (LC) were recorded in each sample. Testicles from males during short days (SHD) had a higher percentage of tubules with RS and ES compared to testicles from males during long days (LHD, 31.3 +/- 0.6 vs 2.1 +/- 0.6%, p < 0.001; 30.9 +/- 0.7 vs 11.0 +/- 0.7%, p < 0.001). Conversely, testicles from males during SHD had a lower percentage of tubules with TS and MS compared to testicles from males during LHD (24.5 +/- 0.8 vs 29.7 +/- 0.8%, p < 0.01; 13.1 +/- 1.2 vs 57.0 +/- 1.2%, p < 0.01). Furthermore, testicles from males during SHD had a higher number of SC and lower number of LC compared to testicles from males during LHD (11.4 +/- 0.1 vs 8.0 +/- 0.1%, p < 0.01; 19.2 +/- 1.0 vs 38.0 +/- 1.0%, p < 0.01). In conclusion, there are seasonal changes in testis cell morphology in the tom which may be related to seasonal sperm production.

The objective of this research was to use a model of unilateral and bilateral occlusion of the ductus deferens in the dog to study the use of alkaline phosphatase (AP) as an indicator of tubular patency. Seven healthy cross bred dogs weighing 10-15 kg BW with normal spermiogram and AP concentrations in semen were used. From each dog, three semen samples were obtained before (intact) and after right (unilateral) and left (bilateral) vasectomy. The AP concentrations were measured in duplicates by a colorimetric method in each of the three fractions (first, second (sperm-rich), third) of each ejaculate. In addition, a macroscopic and microscopic evaluation of each ejaculate was carried out to assure its quality. Data were analysed by least squares analysis of variance using SAS(R). In intact and unilateral vasectomized dogs, 96.6% of AP measured in semen corresponded to the second sperm-rich fraction whereas 1.53 and 1.83% corresponded to the first and third fractions respectively. Total AP concentrations (first and second and third fraction) in vasectomized dogs were lower than in intact animals (19.857 vs 2284.431 +/- 4.347 UAL; p < 0.001). AP concentrations were much lower in bilateral than in unilateral vasectomized dogs (142 vs 39.572 +/- 4.347 UL, p < 0.001). In summary, AP concentrations in semen can be used as an early indicator of unilateral or bilateral lack of patency of the epididymal and deferent ducts in the dog.