The effects of intramuscular or intravenous injections of gonadotropin releasing hormone at fixed-time artificial insemination on pregnancy rates of Bos indicus beef cows
Document title: The effects of intramuscular or intravenous injections of gonadotropin releasing hormone at fixed-time artificial insemination on pregnancy rates of Bos indicus beef cows
Journal: Brazilian archives of biology and technology
Database: PERIÓDICA
System number: 000373460
ISSN: 1516-8913
Authors: 1
2
2
2
1
1
1
1
3
3
1
Institutions: 1Pontificia Universidade Catolica do Parana, Escola de Ciencias Agrarias e Medicina Veterinaria, Sao Jose dos Pinhais, Parana. Brasil
2University of Florida, North Florida Research and Education Center, Marianna, Florida. Estados Unidos de América
3Universidade Federal do Parana, Programa de Pos Graduacao em Processos Biotecnologicos, Curitiba, Parana. Brasil
Year:
Season: May-Jun
Volumen: 57
Number: 3
Pages: 361-366
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Analítico, descriptivo
English abstract The effect of an intramuscular versus intravenous administration of gonadotropin releasing hormone (GnRH) at fixed-time AI (FTAI) on the pregnancy rates of crossbred Bos indicus beef cows was evaluated. Pluriparous nursing calv cows (n=120) were synchronized as follows: d 0 cows received a 2.0 mg injection of estradiol benzoate (EB) and insertion of a controlled intravaginal progesterone releasing device containing 0.558 g of progesterone, d 8 removal of the progesterone device , a 0.15 mg injection of prostaglandin F2α (PGF), a 1.0 mg injection of EB, and 400 IU injection of equine chorionic gonadotropin. Fifty-four hr after PGF, all cows were exposed to FTAI and a 0.084 mg injection of GnRH was administered either via Vena caudalis (n=60), or via Longissimus dorsi (n=60). Cows were inseminated with the same sire and by a single AI technician. Pregnancy was determined by the transrectal ultrasonography on d 40 after AI. Cows receiving the intravenous administration of GnRH had higher (P = 0.04) pregnancy rates than the cows receiving the intramuscular injection of GnRH (65 vs 46.6%, respectively). It was concluded that the intravenous administration of GnRH at the time of AI improved the pregnancy rates of crossbred Bos indicus beef cows submitted to FTAI
Disciplines: Medicina veterinaria y zootecnia
Keyword: Bovinos,
Reproducción y genética animal,
Inseminación artificial,
Gonadotropinas,
Vías de administración,
Tasa de preñez,
Bos indicus
Keyword: Veterinary medicine and animal husbandry,
Animal reproduction and genetics,
Bovines,
Artificial insemination,
Gonadotropins,
Administration routes,
Pregnancy rate,
Bos indicus
Full text: Texto completo (Ver HTML)