title: Fixed-time post-cervical artificial insemination in sows receiving porcine luteinising hormone at oestrus onset.
abstract: Fixed-time post-cervical artificial insemination (FTPCAI) allows a wider use of high indexing boars and a considerable reduction in labour requirements in swine production. The aim of this study was to evaluate fixed-time artificial insemination (FTAI) efficiency using different artificial insemination protocols and porcine luteinising hormone (pLH) to induce ovulation. A total of 597 weaned sows in which oestrus detection was performed once daily (08:00 am) was allocated to three groups: FTPCAI1 (n=199) - sows received a 5-mg (4 ml) intramuscular injection of pLH at oestrus onset, and were inseminated 24h later; FTPCAI2 (n=199) - sows received 5mg of pLH and were inseminated at oestrus onset (0 h) and 24h after; and MultPCAI (n=199) - sows did not receive pLH, and the first AI was performed at oestrus onset (0 h) and repeated every 24h during oestrus. Homospermic doses (1.5 × 10(9) total sperm cells/50 ml) were used in post-cervical artificial insemination (PCAI) in all the treatments. Hormonal treatment did not affect (P>0.05) the interval between oestrus onset and ovulation (overall 32.4h) and there were no differences (P>0.05) in farrowing rate (overall 91.6%) or litter size (overall 12.6 piglets born) among treatments. In sows treated with pLH at oestrus onset, a single PCAI with 1.5 billion sperm cells did not compromise reproductive performance compared with a double PCAI at 24h intervals.
authors.affiliation: Universidade Federal do Rio Grande do Sul - UFRGS, Faculdade de Veterinária, Setor de Suínos, Av. Bento Gonçalves, 9090, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: D L
authors.initials: DL
authors.lastname: Fontana
authors.affiliation: Universidade Federal do Rio Grande do Sul - UFRGS, Faculdade de Veterinária, Setor de Suínos, Av. Bento Gonçalves, 9090, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: R R
authors.initials: RR
authors.lastname: Ulguim
authors.affiliation: Universidade Federal do Rio Grande do Sul - UFRGS, Faculdade de Veterinária, Setor de Suínos, Av. Bento Gonçalves, 9090, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: P E
authors.initials: PE
authors.lastname: Sbardella
authors.affiliation: UFRGS, Faculdade de Agronomia, Departamento de Zootecnia, Av. Bento Gonçalves, 7712, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: M L
authors.initials: ML
authors.lastname: Bernardi
authors.affiliation: Universidade Federal do Rio Grande do Sul - UFRGS, Faculdade de Veterinária, Setor de Suínos, Av. Bento Gonçalves, 9090, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Wentz
authors.affiliation: Universidade Federal do Rio Grande do Sul - UFRGS, Faculdade de Veterinária, Setor de Suínos, Av. Bento Gonçalves, 9090, 91540-000 Porto Alegre, RS, Brazil. Electronic address: fpbortol@ufrgs.br.
authors.forename: F P
authors.initials: FP
authors.lastname: Bortolozzo
mesh_terms: D000818:Animals; D004334:Drug Administration Schedule; D004971:Estrus / Q000187:drug effects*; D004972:Estrus Detection; D005260:Female; D007315:Insemination, Artificial / Q000379:methods / Q000662:veterinary*; D008098:Litter Size; D007986:Luteinizing Hormone / Q000008:administration & dosage*; D011247:Pregnancy; D018873:Pregnancy Rate; D013552:Swine; D014886:Weaning
chemical_list: D007986:Luteinizing Hormone
keywords: Fixed-time insemination; Ovulation; Porcine luteinising hormone; Post-cervical insemination; Swine