Semen characteristics and plasma levels of testosterone after bilateral vasectomy in bucks

Effect of the donor´s age and type of extender (egg yolk versus clarified egg yolk) over the sperm quality of Majorera bucks preserved at 4 ºC: in vitro results and fertility trials

This study assessed the effect of donor´s age and two different extenders in the sperm quality of chilled semen in Majorera bucks. In experiment 1, semen was individually processed from 5 young (10–12 months old) and 4 mature (3–5 years old) bucks and then was diluted in two different extenders: EY (Tris‐glucose, 12% egg yolk) and CEY (Tris‐glucose, 12% clarified egg yolk) and cooled at 4°C; semen quality (sperm motility, percentages of alive spermatozoa, acrosome status and abnormal spermatozoa) was evaluated at 24, 48, 72 and 96 hr after cooling. In experiment II, 72 Majorera goats were assigned to four experimental groups: for groups 24‐EY (n = 18) and 24‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 24 hr, respectively, while for groups 72‐EY (n = 18) and 72‐CEY (n = 18), goats were inseminated with EY and CEY cooled semen for 72 hr, respectively. In vitro results confirmed that only ejaculate volume and sperm concentration were significantly different between young and mature bucks. In addition, semen quality was similar between both diluents, presenting values for the first 48 hr similar to that recorded in fresh samples. The fertility rate was around 70% after 24 hr (4°C) in both groups, but the kidding rate was significantly lower (44.4%, p < .05) in goats inseminated with EY diluent preserved for 72 hr. Our results showed that the semen samples may be stored at 4°C in media with egg yolk or clarified egg yolk, and, therefore, the use of clarified egg yolk may represent a valid alternative to chill semen samples. Finally, young bucks (older than 10–12 months) of Majorera breed could be successfully used in breeding programmes with similar efficacy to older males.

Evaluation of bilateral vasocystostomy for canine sterilization

This study was aimed to evaluate canine vasocystotomy as a testosterone-preserving method of sterilization and investigate its potential post-operative complications. Five healthy adult male dogs underwent surgical procedure to transplant vasa deferentia to the urinary bladder. Under general anesthesia, caudal abdomen was opened and both vasa deferentia were ligated and transected. Then, the proximal free ends were sutured to mucosal layer of urinary bladder on its cranio-dorsal aspect. Serum testosterone level was measured on a weekly basis. Six-week postoperative assessments were performed including semen and urine sampling, ultrasound, contrast vasography, and tissue sampling. Statistical analyses revealed no significant differences in serum testosterone levels compared to its baseline value. Along with non-motile and broken spermatozoa, no cast or crystals were observed in urine samples. Semen analyses revealed azoospermia. No vasal obstruction or contrast leakage was observed in vasographs indicating bilateral patency in all dogs. Normal thickness of the bladder was found in ultrasounds. Histopathology showed normal testicular architecture and no inflammatory response was found in bladder or vas deferens following vasal transplantation. No significant change was found in testicular volume at the end of the study. This study suggested that vasocystostomy could be considered as an alternative method for canine sterilization with no significant changes in the testosterone concentrations and no evidence of postoperative complications. The preservation of testosterone could be regarded as an advantage and makes this approach favorable compared to the routine methods of sterilization especially for herding and guard dogs, because it prevents overpopulation while maintains the functionality.

Prooxidant-antioxidant balance and malondialdehyde over time in adult rats after tubal sterilization and vasectomy

OBJECTIVE

Sterilization (tubal sterilization and vasectomy) is a widely applied contraceptive method worldwide. Although most studies have described sterilization as a safe method, there are reports of tubal ligation (TL) and vasectomy complications. The aim of this study was to evaluate the effects of TL and vasectomy on the serum oxidative stress, specifically prooxidant-antioxidant balance (PAB) and malondialdehyde (MDA) levels, over time.

METHODS

Male and female rats were classified into vasectomy, sham-vasectomy, TL, and sham-TL groups, respectively. The PAB and MDA levels were measured on days 15 and 45 and months 3 and 6 after the intervention. For female rats, blood sampling was performed during the diestrous phase and estradiol and progesterone were also measured.

RESULTS

Serum PAB and MDA increased after TL (p<0.05). Vasectomy increased serum MDA remarkably after 45 days, 3 months, and 6 months (p<0.05). After vasectomy, serum PAB also increased although not significantly. Serum estradiol and progesterone decreased remarkably in the TL group compared to the sham group (p<0.05).

CONCLUSION

Bilateral TL and vasectomy both increase the serum oxidative stress; however the imbalance after TL was very noticeable. As for the TL, the reduction of serum estrogen levels can be involved in this imbalance. Complications followed by TL or vasectomy could be due to increased levels of oxidants. Thus, prescribing antioxidants during and or after surgery may be a solution.

Epididymis ligation: a minimally invasive technique for preparation of teaser rams

OBJECTIVE

To describe a minimally invasive technique for preparation of teaser rams by needle-assisted ligation through the tail of the epididymis.

STUDY DESIGN

Experimental study.

ANIMALS

Mature rams (n=6), estrus-induced ewes (2). METHODS; After local anesthesia, epididymis ligation was achieved by restraining the testis distally within the scrotal sac and passing suture through a hypodermic needle inserted between tail of epididymis and distal pole of testis, caudomedial to craniolateral through the scrotum. The needle was removed leaving the suture in place and the testis pushed up dorsally, then the needle was reinserted through the original holes and the suture passed back through the needle, which was withdrawn. This resulted in the suture forming a complete loop around the epididymis. The suture ends were tied ligating the epididymis. Semen was evaluated pre- and postligation. Testes were removed after 30 days for gross and histologic examination.

RESULTS

Epididymis ligation was accomplished without postoperative complications. Three weeks after the epididymis ligation, no motile and live spermatozoa were found in ejaculates. From 5 to 28 days after epididymis ligation, attraction to ewes and libido was unchanged and similar to 14 days before ligation.

CONCLUSIONS

This novel minimally invasive technique is a simple, alternative method for preparation of teaser rams.

CLINICAL RELEVANCE

This method is simply performed, without skin wounds, and minimal postoperative care is needed. The technique should be readily adaptable to other species.