Canine semen conservation under cooling in different isothermal boxes

Abstract

The aim of this study was to determine the maximum time of conservation in different isothermal boxes of the diluted canine semen under cooling. Semen from eight dogs was collected by digital manipulation. The sperm fraction was evaluated for volume, color, motility, vigor, sperm morphology, acrossomal integrity, osmotic answer and sperm concentration. Then, it was diluted in skimmed UHT milk plus egg yolk (20%) and divided in samples, which were stored in 3L or 5L expanded polystyrene isothermal boxes, containing recyclable ice. These boxes were open after 12h, 18h, 24h and 30h of storage and semen was reevaluated for the characteristics already mentioned. The temperature into the boxes and the environmental temperature were monitored. As main results, the progressive sperm motility was acceptably conserved up to 30h in both boxes, which did not present differences in the conservation of none of the seminal characteristics (P>0.05). However, the temperature into the 3L-box showed a significant elevation starting from the 18h (P<0.05), and the temperature into the 5L-box remained constant for whole the experiment. It is concluded that the canine semen diluted in skimmed UHT milk can be efficiently conserved for up to 30h in 3L or 5L isothermal boxes, containing recyclable ice. But it is pointed out that the 5L-box presents larger safety for the sperm viability, because it is more efficient in the maintenance of a constant temperature. Keywords: Semen, dog, cooling.