title: Use of cholesterol-loaded cyclodextrin in donkey semen cryopreservation improves sperm viability but results in low fertility in mares.
abstract: The use of cholesterol-loaded cyclodextrin (CLC) on semen cryopreservation has been related with better sperm viability in several species; however, the effect on fertility is not known in donkey semen. Ejaculates (n = 25) from five donkeys were diluted in S-MEDIUM with 0, 1, 2 or 3 mg of CLC/120 × 10(6) spermatozoa. Semen was frozen, and thawed samples were evaluated by computer-assisted sperm analyser system (CASA), supravital test, hyposmotic swelling test and fluorescent dyes to assess the integrity of sperm membranes. Mares (n = 60) were inseminated with frozen-thawed semen treated with the doses of 0 or 1 mg CLC. Percentages of sperm with progressive motility and with functional plasma membrane were greater (p < 0.05) in the CLC-treated groups than in the control. Percentages of intact plasma membrane and intact plasma membrane and acrosome detected by fluorescent dyes were also greater (p < 0.05) in CLC-treated groups. Although no difference (p > 0.05) in conception rates was detected between groups (control, 3/30, 10%; CLC-treated, 1/30, 3.3%), fertility was low for artificial insemination programs in mares. Therefore, we firstly demonstrated that frozen semen treated with CLC in S-MEDIA extender before freezing improves the in vitro sperm viability, but semen treated or not with CLC in S-MEDIUM extender results in a very low conception rate in mares inseminated with thawed donkey semen.
authors.affiliation: Department of Animal Science, Federal University of Viçosa, Viçosa, MG, Brazil.
authors.forename: R R
authors.initials: RR
authors.lastname: Oliveira
authors.forename: D M
authors.initials: DM
authors.lastname: Rates
authors.forename: G
authors.initials: G
authors.lastname: Pugliesi
authors.forename: P G
authors.initials: PG
authors.lastname: Ker
authors.forename: R P
authors.initials: RP
authors.lastname: Arruda
authors.forename: E A
authors.initials: EA
authors.lastname: Moraes
authors.forename: G R
authors.initials: GR
authors.lastname: Carvalho
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000494:pharmacology*; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology; D003505:Cyclodextrins / Q000494:pharmacology*; D018397:Equidae / Q000502:physiology*; D005260:Female; D008297:Male; D011247:Pregnancy; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*
chemical_list: D003451:Cryoprotective Agents; D003505:Cyclodextrins; D002784:Cholesterol