Effects of Incubation Temperature at ۳۷ °C on Canine Sperm Quality Before Cooling to ۵ °C

Background: One of the most important aspects of artificial insemination in animals is the practical design of long-term preservation of sperm. Although there are many reports on canine sperm storage methods, an improved system for chilling canine spermatozoa is required for successful breeding programs in companion and working dog colonies.Objectives: This study aimed to compare the effects of incubation temperature at ۳۷ °C on dog sperm parameters before cooling.Methods: Around ۱-۲ mL ejaculated sperm from the testes of ۵ mature, healthy dogs were collected and divided into two groups: C: TRIS+egg yolk ۲۰% (control, without incubation at ۳۷ °C), T: TRIS+egg yolk ۲۰% (treatment group, incubation at ۳۷ °C for ۱۰ minutes). Evaluation of cooled sperm was done by computer-assisted sperm analysis (CASA) for motility test, morphology, eosin-nigrosin vital staining and hypo-osmotic swelling test (HOST) after cooling. Results: In the treatment group, total and progressive motility (PM), curvilinear velocity, straight line velocity, average path velocity (VAP), linearity (LIN), straightness (STR), the proportion of sperm with normal morphology, the proportion of viable sperm and the proportion of sperm positive for HOST were not affected by the interaction of group by time. However, they were lower in treatment than the control group (P<۰.۰۵) and they decreased throughout preservation (P<۰.۰۰۱).Conclusion: Keeping sperm at a temperature of ۳۷ °C and applying heat shock by bain-marie has highly adverse effects on the quality of ejaculated sperm.

کلیدواژه ها:

Incubation ، Dog ، Sperm parameter ، Cooling ، Computer-assisted sperm analysis (CASA)