Effects of Incubation Temperature and Semen Pooling on the Viability of Fresh, Chilled and Freeze-Thawed Canine Semen Samples
Reproduction in Domestic Animals
Volume 47, Issue 6, December 2012, Pages 1049-1055
Batista, M. , Santana, M., Alamo, D., González, F., Niño, T., Cabrera, F., Gracia, A.
Abstract
Contents: This study assessed the effects of different incubation temperatures on semen viability and the influence of pooling on semen longevity. In experiment 1, semen samples were collected from five dogs, individually processed (individual semen: IS) and then aliquots from each male were pooled (pooled semen: PS). Semen samples (IS and PS) were diluted in a Tris-glucose-yolk extender and preserved as fresh (37 and 25°C) and chilled semen (4°C). Sperm motility and the percentages of sperm abnormalities and acrosome membrane integrity were assessed for 24h. Storage at 25 or 4°C for the first 24h yielded similar semen quality, but incubation at 37°C caused drastic reduction in sperm motility from 8h of incubation onwards. In experiment 2, the semen was processed in the same way to that of experiment 1 and then preserved at 25 or 4°C until semen inactivation. Semen that was incubated at 25°C became completely inactive after 3-4days of storage, while semen that was preserved at 4°C presented with more gradually decreased sperm motility (mean values of 40-60% for the first 8days). In addition, the mixing of semen was only observed to influence the sperm quality of the samples stored at 4°C. In experiment 3, semen was collected from five dogs, pooled and frozen in liquid nitrogen; after thawing, it was preserved at 37, 25, 15 and 4°C, and the sperm quality was defined. The motility of the freeze-thawed semen samples decreased quickly in the first 4h after thawing, regardless of the preservation temperature of the thawed semen. This study confirmed that semen preserved at 37°C should be used within a maximum of 12h, while the semen stored at 25°C shows acceptable quality for 24h. Chilled semen presented highest most sustainable quality, especially when semen is processed as pooled semen
