Relationship between Clinical Uterine Findings, Therapy, and Fertility in the Mare

Comparative analysis of breeding patterns and reproductive efficiency of mares in subtropical conditions of Pakistan

BACKGROUND AND AIM

The present study aimed to evaluate and compare the overall and breed-specific seasonal breeding patterns, fertility rates, cyclicity, and follicular dynamics of Arab, Thoroughbred, and Percheron mares under the subtropical conditions of Pakistan.

MATERIALS AND METHODS

A retrospective analysis of climatic data and breeding records of eleven breeding studs spanning four years (2020-2023) was made to find out the overall seasonality in the breeding pattern of mares. Fifty mares of each breed (n = 150 in total) were scanned by ultrasonography for a calendar year to find the cyclicity pattern and follicular dynamics (follicular growth rate, size of ovulatory follicle, and days from estrus till ovulation).

RESULTS AND DISCUSSION

The statistical analysis of breeding records demonstrated a clear pattern of seasonal breeding (p< 0.05). The highest monthly foalings were noted in March (247 ± 45.37), and overall breeding activities peaked in Spring season (p< 0.05). Breed-specific results of Arab, Thoroughbred, and Percheron mares revealed that Arab mares maintained stable breeding activity throughout the year, with the highest activity in spring and peak conception rate in winter (56.25% ± 32.78; p > 0.05). Thoroughbred mares experienced significant seasonal declines from spring to winter with a peak conception rate in winter (63.89% ± 27.37, p > 0.05). Percherons showed the most pronounced seasonal effects, especially with a high fall conception rate (73.04% ± 19.61) and a sharp decrease in winter breeding metrics (p< 0.05). Furthermore, Thoroughbred and Percheron mares displayed the most pronounced seasonal effects on the percentage of cyclic mares 77.3% and 56% in winters (p< 0.05). Moreover, the follicular dynamics of the three breeds also exhibited significant differences (p< 0.05).

CONCLUSION

The current study concludes that seasonal and breed-specific variability exists among the reproductive parameters of Arab, Thoroughbred, and Percheron mares in subtropics, necessitating breed-specific reproductive management measures to maximize mare breeding efficiency.

Vaginal and Uterine Microbiota of Healthy Maiden Mares during Estrus

This descriptive cross-sectional study compared the microbiota of the uterus, vagina, clitoral fossa (CF), and perineal skin in healthy maiden mares during estrus. Twelve synchronized, healthy maiden mares (3-4 years old) from one single recipient mare herd were included. Microbial communities were characterized by amplifying the V3-V4 region of the 16S rRNA gene using the Illumina MiSeq platform. The uterine and vaginal microbiota had significantly lower richness (Chao-1) than the skin (p < 0.05). The uterine and vagina bacterial composition was similar in presence and abundance and could be differentiated from that of the CF and perineal skin. The microbial composition (Jaccard and Bray-Curtis distances) significantly differed across body-site locations (p < 0.05), which explained approximately 14% and 19% of the variation in microbial composition for Jaccard and Bray-Curtis distances, respectively. Firmicutes, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant taxa in the uterus and vagina, with higher proportions of Proteobacteria in the vaginal samples compared to the uterine samples. Streptococcaceae and Staphylococcaceae were present in high abundance in the uterine and vaginal samples, while Lactobacillaceae were not (<10%). We demonstrate that the uterine and vaginal microbiota of healthy maiden mares during estrus is similar but both distinct from that of the CF and perineal skin.

Factors affecting the efficiency of equine embryo transfer (EET) in polo mares under subtropical conditions of Pakistan

Equine embryo transfer (EET) is a prominent technology in the equine breeding industry, and its efficacy is affected by a number of factors. The current study aimed to determine the effects of the breed of donor/recipient mares, estrus/ovulation induction treatment, cooled transportation of embryos, and synchrony between donor and recipient mares on the efficiency of the EET under subtropical conditions of Pakistan. A total of eighty-four (n = 84) Polo-playing donor mares (Argentino-polo = 41 and Anglo-Arab = 43) and seventy (n = 70) recipient mares (light breed = 26 and heavy breed = 44) were used for EET. The donor mares exhibiting natural estrus (n = 28) were detected by teaser a stallion, and corpus luteum (CL) having mares (n = 56) were treated with prostaglandin (150 μg of Cloprostenol) for estrus induction. The mares' follicular growth was monitored through ultrasonography until the dominant follicle's size reached 35 mm or more with a moderate to obvious uterine edema score. Afterward, the mares were treated either with GnRH, i.e., 50 μg of Lecirelin acetate (n = 41) or Ovusyn, i.e., 1500 IU hCG (n = 43). Insemination with chilled semen was performed 24 hours later. The embryos were collected non-surgically, 7 or 8 days after ovulation, from the donor mares. The collected embryos were transferred into the well-synchronized recipient mares as fresh (n = 44) or chilled (n = 26) embryos. The pregnancy after ET was checked through ultrasonography. Statistical analysis revealed that the embryo recovery rate (ERR) remained significantly higher (P<0.05) for the Prostaglandin (PG) treated group of donors as compared to the natural heat group of donors. The breed of donor mares, type of ovulatory treatment given, and day of embryo collection did not significantly (P>0.05) affect the ERR. There was no significant effect of the type (fresh vs chilled), classification, and stage of development of embryo on pregnancy outcomes (P>0.05). ET pregnancy rate was significantly affected by the breed of recipient mares and ovulation synchrony between donor and recipient mares (P<0.05). In conclusion, under the subtropical conditions of Pakistan, PG-based estrus induction of donor mares, breed of recipient mares, and ovulation synchrony between the donor and recipient mares had a substantial effect on the efficiency of EET.

Use of cytobrush for bacteriological and cytological diagnosis of endometritis in mares

Background and Aim

A combined microbial and cytological examination of uterine samples is the main diagnostic method for endometritis in mares. This study aimed to describe a procedure for using the same uterine cytobrush (CB) for both bacteriological and cytological evaluation.

Material and Methods

The procedure consists of rolling the CB onto a sterilized glass slide immediately after collection and before the transfer into a sterile saline solution. In Experiment 1, a comparison between bacteriological results of the cotton swab (CS) and CB or pellet was made in 10 mares; in Experiment 2, bacteriological and cytological results were compared between different processing methods of CB in 28 mares; in other 6 mares, a CB was processed for cytology only, to investigate the reasons for the low cellularity of the pellet.

Results

The agreement between culture results from the CB and CS was evaluated, and a comparison between the cytological data obtained by different processing methods of CB was performed. The perfect agreement between the CB and CS microbiological results was found. The described procedure enables useful diagnostic smears for cytology. Moreover, the seeding of both the tip of CB and the saline solution used for the transport produced accurate bacteriological results.

Conclusion

The protocol described in this study for the use of CB for both cytological and bacteriological analysis could be used for the diagnosis of endometritis. To maximize diagnostic sample quality, cytology slides must be prepared with meticulous care in the field to preserve cellular integrity and minimize artifacts.

Clinical and subclinical endometritis in dromedary camels: An overview of definition and clinical presentation, etiopathogenesis, diagnostic biomarkers, and treatment protocols

The current review collected and analyzed research on clinical endometritis (CE) and subclinical endometritis (SCE) in dromedary camels in terms of definition and clinical presentation, etiopathogenesis, diagnostic biomarkers, and treatment protocols. CE is characterized by uterine inflammation with abnormal vaginal discharges, while SCE comprises uterine inflammation with no clinical signs and is described as the infiltration of polymorphnuclear cells into the endometrium. CE is the prevalent clinical finding of barren female dromedaries (18-60 %). SCE has been detected in 9.9 % of infertile female dromedaries. CE and SCE are observed mainly in repeat breeding females. Unhygienic reproductive management, unsanitary dealings during parturition, and postpartum problems are major risk factors. Environmental stress, immunodeficiency, mucus abrasion, or the presence of other opportunistic microbes are predisposing factors. Trueperella pyogenes, Escherichia coli, Pseudomonas aeruginosa, Streptococcus spp., and Staphylococcus spp. are the major uterine isolates obtained from females with CE, while Bacillus spp., Staphylococcus spp., and Candida albicans are the most frequent isolates of SCE. CE and SCE reveal biomarker changes that could aid in the diagnosis of this common reproductive disorder. Only a few treatment protocols for CE and SCE have been tried and proven to work in camel practice. However, there is room for the new, challenging treatment programs proposed in this review. This review also provides a compilation that may be of use to future research and to those working in the field of camel reproduction.