title: Quality of chilled and cold-stored (5 °C) canine spermatozoa submitted to different rapid cooling rates.
abstract: The aim of this study was to evaluate the sperm quality in chilled canine semen using diﬀerent cooling rates from room temperature (23 °C) to 5 °C and subsequently cold-stored at 5 °C for up to 96 hours. In experiment 1, semen samples from five dogs were pooled, diluted in Tris-fructose-citrate extender with 20% egg yolk and split into four aliquots that were chilled to 5 °C using diﬀerent cooling rates of 2.25, 0.9, 0.45, and 0.2 (control) °C/min. In experiment 2, semen from five dogs was processed individually as described above and split into two aliquots that were chilled to 5 °C using rates of either 2.25 °C/min or 0.2 °C/min. In both experiments, the sperm quality (i.e., sperm motility and viability) was evaluated before cooling and after 0, 24, 48, 72, and 96 hours of storage at 5 °C. The total motility, progressive motility, and quality of movement parameters were assessed using computer-assisted analysis system, and the percentage of viable spermatozoa was determined using ﬂow cytometry (H-42/PI//FITC-PNA). The cooling rate did not inﬂuence the sperm quality parameters at any of the evaluation times. All evaluated males showed the same response to chilling semen at a rapid cooling rate. Storage time negatively inﬂuenced (P < 0.05) sperm motility, regardless of the cooling rate used. In conclusion, canine sperm could be chilled and stored for 96 hours at 5 °C in a Tris-fructose extender with 20% egg yolk using rapid cooling rates, with values for sperm quality similar to those from a conventional protocol.
authors.affiliation: Department of Animal Medicine and Surgery, Murcia University, Spain. Electronic address: crb45340@um.es.
authors.forename: C
authors.initials: C
authors.lastname: Rodenas
authors.affiliation: Department of Animal Medicine and Surgery, Murcia University, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Parrilla
authors.affiliation: Department of Animal Medicine and Surgery, Murcia University, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Roca
authors.affiliation: Department of Animal Medicine and Surgery, Murcia University, Spain.
authors.forename: E A
authors.initials: EA
authors.lastname: Martinez
authors.affiliation: Department of Animal Medicine and Surgery, Murcia University, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Lucas
mesh_terms: D000818:Animals; D003080:Cold Temperature; D004285:Dogs / Q000502:physiology*; D008297:Male; D055101:Semen Analysis / Q000662:veterinary*; D012662:Semen Preservation / Q000662:veterinary*; D013997:Time Factors
keywords: Canine; Cold storage; Cooling rates; Spermatozoa