Intratesticular transplantation of allogenic mesenchymal stem cells mitigates testicular destruction after induced heat stress in Miniature-horse stallions.

Testicular degeneration (TD) is the most frequent cause of sub or infertility in stallions. Currently, mesenchymal stem cells (MSC) have been studied as a therapeutic option for several diseases including induced-TD in laboratory animals. Therefore, this study aimed to evaluate the effect of intratesticular MSC therapy on the testicular histology of stallions submitted to scrotal heat stress. Ten healthy Miniature-horse stallions were submitted to testicular heat stress induced by a heating wrap device (42-45°C). Afterward, the stallions were divided into two groups and treated seven days later. MSCs-treated stallions were treated with an intratesticular injection of 10 × 106 of MSCs diluted in 5 mL of PBS, whereas placebo-treated stallions had 5 mL of PBS intratesticular injected. All stallions had testicular biopsies collected seven days before and one- and 14-days post-heat stress and were castrated 30 days after testicular insult. Tissue sections were stained with H&E and evaluated for the tubular and luminal diameter, epithelial thickness, seminiferous tubules (STs) integrity, the number of spermatozoa in the STs, and the percent of abnormal STs. Significance was set at P≤0.05. In both groups, testicular heat stress damaged the STs (P<0.05). However, STs' parameters were improved in MSCs-treated stallions compared to placebo-treated stallions 30 days after the testicular insult (P<0.05). In conclusion, the results of the present study suggest that intratesticular MSC therapy provided a therapeutic advantage in rescuing acute TD in stallions. However, further studies are essential to evaluate the benefits of this therapy on semen parameters and stallions with idiopathic TD.

New Treatment for Urethral Rent in Stallions.

The aim of this report is to describe a new methodology to successfully treat stallions diagnosed with urethral rent. Four stallions of ages ranging from 7 to 12 years (median 9) with hemospermia were admitted for clinical evaluation, breeding soundness examination, and urethroscopy for inspection of the urethra and vesicular glands. Once the presence of urethral rent was identified and/or other sources of hemorrhage were excluded, a topical treatment was performed with 4% Policresulen solution (Albocresil). The treatment was carried out by infusing 100 mL of the solution into the lumen of the urethra through a catheter placed up to the region of the ischial arch. This procedure was repeated once daily, or at 48 hours intervals, resulting in a total of 4-7 infusions. In all cases, chemical cauterization was efficient in the healing of the urethral rent. However, due to masturbation during treatment, one animal did not completely heal, and the treatment with the Policresulen was prolonged. It is believed that the low pH of the solution resulted in urethritis, which was treated with systemic therapy of antibiotic and anti-inflammatory nonsteroidal. Topical treatment with 4% Policresulen was found to be efficient in the chemical cauterization of urethral rent in stallions. This treatment was efficient, practical, less invasive, and less costly than the alternative of surgical methods, which are more invasive and require longer recovery time of the animal. However, sexual rest and the elimination of sexual stimuli from the environment are essential management in association with this therapeutic method.

Different extenders in the cryopreservation of bovine epididymal spermatozoa.

The objective of this study was to evaluate the effects of two different egg yolk extenders incubated with or without Sperm Talp on the motility and plasma membrane integrity of cryopreserved bovine epididymal spermatozoa after freezing. Twenty-five testicles with epididymides from mature bulls were collected at the abattoir. Epididymal sperm recovery was performed by retrograde flushing using a skim milk-extender (Botu-Semen™). After recovery, sperm were incubated either without or with Sperm Talp and then submitted to centrifugation. For the freezing process, half of the testes were processed with Tris egg yolk extender, and half were processed with Botu-Bov™ egg yolk extender. Samples incubated in Sperm Talp exhibited better results than epididymal spermatozoa that were incubated without Sperm Talp (p<0.05). Both Botu-Bov™ and Tris could be utilised to freeze sperm from the bovine epididymides if the sperm were previously incubated with Sperm Talp. The extenders examined in this work did not differ in their effect on plasma membrane integrity after freezing.

Effect of glycerol on the viability and fertility of cooled bovine semen.

The aim of the present study was to compare the viability and fertility of bovine semen diluted in Botu-Bov (BB) commercial extender with and without the cryoprotectant glycerol then cooled at 5 degree C for 24 hours in the Botu-Flex passive cooling system and of semen diluted in BB with glycerol then frozen. One ejaculate of 30 Nelore Bos Taurus indicus bulls between 24 and 30 months of age was used for in vitro analysis. Sperm kinetics and cell viability were analyzed using computer-assisted sperm analysis and flow cytometry, respectively. Three Nelore bulls approximately 30 month old were used for in vivo test using fixed-time artificial insemination for the fertility analysis. The ejaculates were divided into three experimental groups: semen in BB extender with 7% glycerol cooled at 5 °C for 24 hours (cooled semen with cryoprotectant), semen in BB without glycerol cooled at 5 °C for 24 hours (cooled semen without cryoprotectant), and semen diluted in BB with 7% glycerol then subsequently frozen rather than cooled (frozen semen). For the fertility analysis, 762 Nelore cows (B taurus indicus) were randomly inseminated using fixed-time artificial insemination. For the groups corresponding to cooled semen with cryoprotectant, cooled semen without cryoprotectant, and frozen semen, 278, 268, and 216 cows were inseminated, respectively, and the resulting conception rates were 51% a, 44%ab and 41%b (P < 0.05), respectively. In conclusion, the fertility rates improved, when samples were cooled with glycerol at 5 °C for 24 hours compared with the frozen samples.