title: Effect of low density lipoprotein on the quality of cryopreserved dog semen.
abstract: Egg yolk is included in extenders for semen cryopreservation due to its protective effect against cold shock, which is attributed to the presence of low density lipoprotein (LDL). This study evaluates how semen quality is affected by using LDL as a replacement for egg yolk in extenders for cooled and frozen dog semen. In Experiment 1, semen was extended in TRIS-glucose at 5 degrees C, in four treatments: 20% egg yolk (T1); 6% (T2); 8% (T3); and 10% LDL (T4). Sperm motility and membrane integrity after 24, 48, 72 and 96 h and the 50% conservation rate of motile spermatozoa (50 M) were evaluated. The 50 M was less for T1 than for the other treatments (P<0.01), but T2-T4 did not differ (P>0.05). In Experiment 2, glycerol at 10% was included in the freezing extender, in treatments similar to those from Experiment 1. Sperm motility and membrane integrity did not differ for T2, T3 and T4 at any period in Experiment 1 and after thawing in Experiment 2 (P>0.05), but were greater for all LDL treatments than for T1 (P<0.01), in both experiments. Thus, LDL can replace egg yolk in the composition of the TRIS-glucose extender for cooled or frozen dog semen.
authors.affiliation: Centro de Biotecnologia, Faculdade de Veterinária - Universidade Federal de Pelotas - UFPel, Campus Universitário s/n - Caixa Postal 354 - 96010-900 - Pelotas - RS - Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Varela Junior
authors.forename: C D
authors.initials: CD
authors.lastname: Corcini
authors.forename: R R
authors.initials: RR
authors.lastname: Ulguim
authors.forename: M V F
authors.initials: MV
authors.lastname: Alvarenga
authors.forename: I
authors.initials: I
authors.lastname: Bianchi
authors.forename: M N
authors.initials: MN
authors.lastname: Corrêa
authors.forename: T
authors.initials: T
authors.lastname: Lucia
authors.forename: J C
authors.initials: JC
authors.lastname: Deschamps
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002645:Chickens; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004285:Dogs; D004531:Eggs / Q000032:analysis; D005260:Female; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013081:Sperm Motility / Q000187:drug effects
chemical_list: D008077:Lipoproteins, LDL