title: In vitro and in vivo fertility of ram semen cryopreserved in different extenders.
abstract: Seminal traits of frozen-thawed (FT) ram semen and in vitro and field fertility in native Portuguese breeds were evaluated in 4 experiments. In exp. 1 and 2 the cryopreservation capacity of 2 extenders, E1 (15% egg yolk-EY) and E2 (4.5% EY and trehalose) was compared through morphological evaluation and in vitro fertilizability of FT ram semen. Exp. 3 aimed to determine the usefulness of in vitro homologous/heterologous fertilization tests as tools for predicting ram fertility. Exp. 4 was conducted to verify if the identified differences between the 2 extenders could be confirmed by field fertility. E1 showed a better cryoprotective action expressed by higher in vitro and field fertility results. In conclusion, EY is difficult to be replaced in ram semen extenders. Heterologous fertilization seems to be a useful tool for predicting fertility of FT ram semen.
authors.affiliation: Unidade de Recursos Genéticos, Reprodução e Melhoramento Animal, Quinta da Fonte Boa, 2005-048 Vale de Santarém, Portugal.
authors.forename: S S
authors.initials: SS
authors.lastname: Valente
authors.forename: R M
authors.initials: RM
authors.lastname: Pereira
authors.forename: M C
authors.initials: MC
authors.lastname: Baptista
authors.forename: C C
authors.initials: CC
authors.lastname: Marques
authors.forename: M I
authors.initials: MI
authors.lastname: Vasques
authors.forename: M V C Silva
authors.initials: MV
authors.lastname: Pereira
authors.forename: A E M
authors.initials: AE
authors.lastname: Horta
authors.forename: J P
authors.initials: JP
authors.lastname: Barbas
mesh_terms: D000818:Animals; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004530:Egg Yolk; D005260:Female; D005298:Fertility / Q000502:physiology*; D005307:Fertilization in Vitro / Q000662:veterinary; D007315:Insemination, Artificial / Q000662:veterinary; D008297:Male; D012661:Semen / Q000502:physiology*; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D012756:Sheep / Q000502:physiology*; D013081:Sperm Motility; D013094:Spermatozoa / Q000002:abnormalities / Q000502:physiology; D014199:Trehalose
chemical_list: D014199:Trehalose