title: Use of sexed sorted semen for fixed-time artificial insemination or fixed-time embryo transfer of in vitro-produced embryos in cattle.
abstract: Artificial insemination and in vitro embryo production are powerful tools for disseminating superior genetic qualities and improving the reproductive performance of dairy and beef cattle. In conjunction with these biotechnologies, sexed-sorted semen has been used to obtain offspring of a predetermined sex. This study compared the pregnancy rates obtained using in vitro fertilization/timed embryo transfer (IVF/TET) and timed artificial insemination (TAI), both performed using sexed-sorted (Y-chromosome-bearing) semen obtained from the same bull. For the in vitro embryo production, the ovaries of 250 Nelore cows with known histories were collected in the slaughterhouse and used for IVF. After evaluation of the recipients (IVF/TET group; n = 974), the resultant embryos were transferred to the females with corpus luteum (n = 822). The pregnancy-related data for this group were compared with those for the TAI group (n = 974). Ultrasonography was performed at 60 days to determine the pregnancy status and confirm the sex of the fetus. A total of 2008 oocytes produced 1050 embryos, with 52% of them reaching the blastocyst stage. The pregnancy rate and the accuracy in determining the fetal sex were 35.4% (345/974) and 95.07% (328/345), respectively, for the IVF/TET group and 30% (293/974; P < 0.05) and 94.88% (278/293), respectively, for the TAI group. In the present study, we concluded that male calves could be better obtained using IVF/TET rather than TAI; therefore, this strategy can be considered to increase the pregnancy rate of beef cattle.
authors.affiliation: Departamento de Clínica e Cirurgia Veterinárias da Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brasil; Prole-Reprodução Animal Assistida Ltda, Belo Horizonte, MG, Brasil. Electronic address: carlos@prolefiv.com.br.
authors.forename: C A G
authors.initials: CA
authors.lastname: Pellegrino
authors.affiliation: Departamento de Clínicas Veterinárias da Universidade Estadual de Londrina-UEL, Londrina, PR, Brasil.
authors.forename: F
authors.initials: F
authors.lastname: Morotti
authors.affiliation: In Vitro Brasil Ltda, Mogi Mirim, SP, Brasil.
authors.forename: R M
authors.initials: RM
authors.lastname: Untura
authors.affiliation: In Vitro Brasil Ltda, Mogi Mirim, SP, Brasil.
authors.forename: J H F
authors.initials: JH
authors.lastname: Pontes
authors.affiliation: Departamento de Clínica e Cirurgia Veterinárias da Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brasil.
authors.forename: M F O
authors.initials: MF
authors.lastname: Pellegrino
authors.affiliation: Departamento de Clínica e Cirurgia Veterinárias da Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brasil.
authors.forename: J P
authors.initials: JP
authors.lastname: Campolina
authors.affiliation: Departamento de Clínicas Veterinárias da Universidade Estadual de Londrina-UEL, Londrina, PR, Brasil.
authors.forename: M M
authors.initials: MM
authors.lastname: Seneda
authors.affiliation: Departamento de Clínica e Cirurgia Veterinárias da Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brasil.
authors.forename: F A
authors.initials: FA
authors.lastname: Barbosa
authors.affiliation: Departamento de Clínica e Cirurgia Veterinárias da Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brasil.
authors.forename: M
authors.initials: M
authors.lastname: Henry
mesh_terms: D000818:Animals; D002417:Cattle; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D007315:Insemination, Artificial / Q000662:veterinary*; D008297:Male; D011247:Pregnancy; D012743:Sex Preselection / Q000662:veterinary*
keywords: Embryo transfer; IVF; Pregnancy rate; Sexed-sorted sperm; TAI