No abstract

This study aimed to determine the accuracy of assessing stallion sperm motility using a light microscope, a cell phone camera, and a free computer-assisted semen analysis (FCASA) package for ImageJ. The total motility of frozen (n=22) and cooled (n=48) equine semen was determined by FCASA and compared to the results of subjective visual analysis (SVA) by two technicians. Frozen samples were also evaluated by a commercial computer-assisted semen analysis (CCASA) system. The Friedman test revealed no significant differences (P>0.05) between cooled samples analyzed by FCASA (38.0) and SVA (technician 1, 40.0; technician 2, 40.0), nor between frozen samples analyzed by FCASA (23.36 ± 15.9), SVA (25.5 ± 18.8 and 25.8 ± 18.5), and CCASA (25.2 ± 18.3). However, mean FCASA results were underestimated by 7.2% compared with CCASA. The correlation between FCASA and CCASA was significant and strong (P<0.0001, r=0.95). Chi-squared tests indicated that FCASA provided similar results (P=0.14) to the reference method (CCASA), but SVA had lower accuracy (P=0.04). ImageJ analysis of cell phone videos captured under a light microscope can be used for estimation of stallion sperm motility with comparable accuracy to commercial systems.

The present study was designed to assess the effect of conventional artificial insemination (CAI) and deep intrauterine artificial insemination (DAI) using different concentrations of spermatozoa on the production of embryos in mares during two breeding season (BS). Seventy-four estrus cycles from 13 crossbred mares (Criollo/English Thoroughbred/Quarter horses) were evaluated, considering the location of semen deposition and doses of fresh semen. The animals were assigned to two treatments: treatment CAI (AI on the uterine body; n = 38) and treatment DAI (AI at the apex of the uterine horn, ipsilateral to an ovary with a preovulatory follicle (POF); n = 36). The animals in estrus were evaluated by ultrasonography to measure the dimensions of the POF. It was observed that POF was larger than 33 mm in diameter than uterine edema and a cervical opening grade of 3, 750 mg of deslorelin acetate (IM) was injected. Twenty-four hours later, AI was performed. The CAI mares received 500 ×10 6 progressively mobile spermatozoa (PMS) and the DAI mares received 250 ×10 6. Embryo collection occurred on days 7 or 8. The embryo recovery rate (ERR) was 68.4 % (26/38) for CAI and 72.2 % (26/36) for DAI. No significant difference was found for the ERR for either of the two AI methods or the sperm doses used. In conclusion, both AI methods can be used successfully in horses and it is possible to reduce the dose of PMS by 50 % when using DAI without decreasing the fertility rate. The production of embryos may be performed several times during the breeding season in the same mare.

The study aimed to compare two techniques for plasma semen removal from 11 stallions using semen centrifugation and semen filtration. Two hundred and thirteen semen samples were frozen and evaluated. The samples were distributed into two groups: centrifuged semen group (GSC) and filtered semen group (GSF). The semen was evaluated fresh and after freezing based on sperm movement (vigor) and sperm motility. After the analysis of the fresh ejaculate, the samples were submitted to centrifugation (600 g/10 minutes) or filtration through synthetic hydrophilic membrane SpermFilter and were frozen. Significant differences were found for the characteristics of motility (P = 0.0002) and vigor (P = 0.0221) between GSC and GSF groups in the pre-freezing time. Sperm motility was observed in 74.6 % (GSC) and 79.4 % (GSF) in pre-freezing time. After freezing phase, sperm motility resulted in 63.4 % (GSC) and 65.8 % (GSF) (P = 0.2303); and vigor showed a reduction in the number of samples classified for score 4, and a predominance of the samples classified in scores 2 and 3 in both groups with no difference between groups. It was concluded that the different methods of seminal plasma removal used (centrifugation or filtration) did not influence sperm quality after freezing; the semen filtration was better in the pre-freezing moment showing the best technique for the use of fresh semen.