Estratégias hormonais para aumentar a taxa de prenhez em novilhas nelore pré-púberes
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Data
2012-12-12
Autores
Rodrigues, Adnan Darin Pereira [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Quatro experimentos foram realizados para avaliar estratégias hormonais para induzir ovulação em novilhas Nelore. No experimento 1, (n = 1039) as novilhas receberam um dispositivo intravaginal contendo 1,9 g de P4 previamente utilizado por 27 dias (Quarto uso; CIDR-4) no Dia -12 ou nenhum tratamento (CIDR-0). O dispositivo foi removido no Dia 0 no tratamento CIDR-4 e a detecção de estro e IA foram realizadas nos Dias 1 a 7. No Dia 8, as novilhas não detectadas em estro foram avaliadas para determinar a presença do CL e receberam o mesmo tratamento novamente, seguido por detecção de estro e IA nos Dias 21 a 27. Todas as novilhas nos Experimentos 2 (n = 896), 3 (n = 839) e 4 (n = 948) receberam o tratamento CIDR-4 no Dia -12. No Experimento 2, as novilhas foram aleatoriamente distribuídas em um grupo Controle (sem tratamento adicional) ou para receberem 200 UI im de gonadotrofina coriônica equina (eCG) no Dia 0. No Experimento 3, as novilhas receberam os mesmos tratamentos descritos no Experimento 2 ou um tratamento que incluiu 200 UI im de eCG mais 0,5mg im de cipionato de estradiol (eCG+ECP) no Dia 0. No Experimento 4, as novilhas receberam os mesmos tratamentos descrito no Experimento 3 ou apenas 0,5mg im de ECP (ECP) no Dia 0. Nos Experimentos 2 e 3 , detecção de estro e IA foram realizadas nos Dias 1 a 7 e no Dia 8 as novilhas não detectadas em estro foram avaliadas para determinar presença de CL. No Experimento 4, as novilhas foram avaliadas para determinar a presença de CL entre os Dias 10 e 14. No Experimento 1, as novilhas tratadas com CIDR-4 tiveram maiores taxas de detecção de estro, indução de ovulação e prenhez comparadas ao Grupo CIDR-0. No Experimento 2, as novilhas tratadas com eCG tiveram maiores taxas de de detecção de estro, indução de ovulação e prenhez em...
Four experiments were conducted to evaluate hormonal strategies to induce ovulation in Nellore heifers. In Experiment 1, (n = 1039) heifers received a CIDR of fourth use (CIDR-4) on Day -12 or no CIDR (CIDR-0). The CIDR was removed on Day 0 in the CIDR-4 treatment, and estrus detection and AI were performed from Days 1 to 7. On Day 8, heifers not detected in estrus were evaluated for CL presence and received the same treatment again, followed by estrus detection and AI from Days 21 to 27. All heifers in Experiments 2 (n = 896), 3 (n = 839), and 4 (n = 948) received the CIDR-4 treatment on Day -12. In Experiment 2, heifers were randomly assigned to a Control group (no additional treatment) or to receive equine chorionic gonadotropin (eCG; 200 IU eCG im) on Day 0. In Experiment 3, heifers received the same treatments as in Experiment 2, or a treatment that included eCG and estradiol cypionate (eCG+ECP; 200 IU im of eCG plus 0.5 mg estradiol cypionate im) on Day 0. In Experiment 4, heifers received the treatments described in Experiment 3 or only ECP (ECP; 0.5 mg ECP) on Day 0. In Experiments 2 and 3, estrus detection and AI was performed from Days 1 to 7 and on Day 8 heifers not detected in estrus were evaluated for CL presence. In Experiment 4, heifers were evaluated for presence of a CL between Days 10 and 14. In Experiment 1 heifers treated with CIDR-4 had greater estrus detection, ovulation induction and pregnancy rates than in the CIDR-0 group. In Experiment 2, heifers treated with eCG had greater estrus detection, ovulation induction and pregnancy rates in 7 d than heifers in the Control group. In Experiment 3, heifers treated with eCG + ECP had greater estrus detection, ovulation induction and pregnancy rates than the Control and eCG treatments. In Experiment 4, ovulation induction was greater for... (Complete abstract click electronic access below)
Four experiments were conducted to evaluate hormonal strategies to induce ovulation in Nellore heifers. In Experiment 1, (n = 1039) heifers received a CIDR of fourth use (CIDR-4) on Day -12 or no CIDR (CIDR-0). The CIDR was removed on Day 0 in the CIDR-4 treatment, and estrus detection and AI were performed from Days 1 to 7. On Day 8, heifers not detected in estrus were evaluated for CL presence and received the same treatment again, followed by estrus detection and AI from Days 21 to 27. All heifers in Experiments 2 (n = 896), 3 (n = 839), and 4 (n = 948) received the CIDR-4 treatment on Day -12. In Experiment 2, heifers were randomly assigned to a Control group (no additional treatment) or to receive equine chorionic gonadotropin (eCG; 200 IU eCG im) on Day 0. In Experiment 3, heifers received the same treatments as in Experiment 2, or a treatment that included eCG and estradiol cypionate (eCG+ECP; 200 IU im of eCG plus 0.5 mg estradiol cypionate im) on Day 0. In Experiment 4, heifers received the treatments described in Experiment 3 or only ECP (ECP; 0.5 mg ECP) on Day 0. In Experiments 2 and 3, estrus detection and AI was performed from Days 1 to 7 and on Day 8 heifers not detected in estrus were evaluated for CL presence. In Experiment 4, heifers were evaluated for presence of a CL between Days 10 and 14. In Experiment 1 heifers treated with CIDR-4 had greater estrus detection, ovulation induction and pregnancy rates than in the CIDR-0 group. In Experiment 2, heifers treated with eCG had greater estrus detection, ovulation induction and pregnancy rates in 7 d than heifers in the Control group. In Experiment 3, heifers treated with eCG + ECP had greater estrus detection, ovulation induction and pregnancy rates than the Control and eCG treatments. In Experiment 4, ovulation induction was greater for... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Nelore (Zebu), Novilho - Reprodução, Ovulação - Indução, Puberdade, Progesterona, Produção animal, Heifers
Como citar
RODRIGUES, Adnan Darin Pereira. Estratégias hormonais para aumentar a taxa de prenhez em novilhas nelore pré-púberes. 2012. xiii, 66 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia de Botucatu, 2012.