Desempenho reprodutivo em novilhas Bos indicus e Bos taurus X Bos indicus submetidas a protocolos de sincronização da ovulação
Carregando...
Data
2016-12-12
Autores
Rodrigues, Adnan Darin Pereira [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo dessa tese foi avaliar o desempenho reprodutivo de novilhas Bos indicus (BI) e Bos taurus x Bos indicus (CR) submetidas a protocolos de sincronização da ovulação. No Capitulo 2, novilhas BI e CR púberes e pré-púberes foram submetidas a estratégia reprodutiva proposta por Rodrigues et al. (2014) e um grupo de novilhas púberes foram sincronizadas com o protocolo de IATF padrão. No Capítulo 3, novilhas BI e CR foram submetidas a estratégia reprodutiva aos 12 meses de idade. No Capítulo 4, foi avaliado o efeito da concentração circulante de P4 no Dia 9 do protocolo de IATF e tratamento com eCG em novilhas BI e CR. No experimento do Capítulo 2 uma maior porcentagem de novilhas BI estavam pré-púberes no início do experimento comparadas as novilhas do grupo CR. A taxa de indução não foi diferente entre novilhas BI e novilhas CR. A raça interferiu na prenhez à IATF na Fazenda 1, mas não interferiu na Fazenda 2. Novilhas que não responderam ao protocolo de indução tiveram menor taxa de prenhez à IATF em relação aos demais grupos experimentais. No experimento do Capítulo 3, a presença de CL no D0 não diferiu entre os grupos genéticos. Animais mais pesados apresentaram maior presença de CL, independentemente de raça. Houve efeito de CL no D0 na taxa de prenhez à IATF. Não foi detectada interação entre presença de CL e raça na prenhez, sendo que novilhas BI tiveram menor P/IA do que as novilhas CR. Houve interação entre peso e CL no D0 na P/IA, sendo que em novilhas com CL no D0 o peso não interferiu na probabilidade de prenhez, entretanto para animais sem CL quanto maior peso corporal, maior a probabilidade de prenhez. No experimento do Capítulo 4, a concentração de progesterona no Dia 9 com maior especificidade e sensibilidade para taxa de prenhez foi 2,03 ng/mL. O diâmetro folicular no Dia 9 foi maior para novilhas CR do que para novilha BI e para BAIXA P4 comparado a ALTA P4. O diâmetro folicular no Dia 11 tendeu a ser maior para a BAIXA P4 do que ALTA P4. A probabilidade de prenhez foi negativamente associada à concentração de P4 no Dia 9. A taxa de ovulação foi maior para o tratamento eCG comparado ao Controle. Novilhas CR tiveram maior taxa de concepção e maior taxa de prenhez do que novilhas BI. Novilhas do grupo BAIXA P4 tiveram maiores taxas de concepção e prenhez do que ALTA P4. Conclui-se que é possível induzir a primeira ovulação em novilhas pré-púberes Bos indicus e Bos taurus x Bos indicus, e realizar o protocolo de IATF logo após a indução, sendo que o protocolo apresenta bons resultados em novilhas de 12 a 27 meses de idade, desde que atendidas as exigências nutricionais.
The aim of this dissertation was to evaluated the reproductive performance of Bos indicus (BI) and Bos taurus x Bos indicus heifers submitted to a synchronization of ovulation protocol. In Chapter 2, pubertal and prepubertal BI and CR heifers were submitted to the reproductive program proposed by Rodrigues et al. (2014) and a group of pubertal heifers were synchronized with the standard TAI protocol. In Chapter 3, pubertal and prepubertal BI and CR heifers were submitted to the reproductive program at the age of 12 months. In Chapter 4, was evaluated the effects of progesterone concentration at Day 9 of the TAI protocol and treatment with eCG in BI and CR heifers. In the experiment of Chapter 2 a greater number of BI heifers were pubertal at the beginning of the experimental period than CR heifers. The induction rate did not differ between BI and CR heifers. Breed of the heifers impacted pregnancy rate to TAI in Farm 1, but not in Farm 2. Heifers that did not respond to the induction protocol had lower pregnancy rate when compared to the others experimental groups. In the experiment of Chapter 3, the CL presence on D0 did not differ between breeds. Independent of the genetic group heavier heifers were more likely to have a CL on D0. There was an effect of CL presence at D0 on P/AI vs. Without CL. The interaction between CL presence on D0 and genetic group did not affect P/AI, and BI heifers had lower P/AI in comparison to CR heifers. An interaction between CL presence on D0 x weight was detected for P/AI. In heifers with CL, the weight did not have effect on P/AI; however, in heifers without CL, heavier heifers were more likely to become pregnant. In the experiment of Chapter 4, the progesterone concentration that has more sensibility and specify for pregnancy at Day 9 was 2.03 ng/mL. Follicle diameter at D9 was greater for CR heifers than BI heifers and in Low P4 compared to High P4. The follicle diameter at D11 tended to be greater for Low P4 than High P4. Probability of pregnancy was negatively associated with P4 level at Day 9. Ovulation rate was greater for eCG compared to Control. Crossbred heifers had greater conception rate and greater pregnancy rate than BI. LOW P4 heifers have greater conception and pregnancy rate than HIGH P4. In conclusion, it is possible to induce first ovulation in BI and CR heifers followed by the TAI protocol with satisfactory pregnancy rates in heifers from 12 to 27 months old, after puberty induction, if the nutritional requirements are achieved.
The aim of this dissertation was to evaluated the reproductive performance of Bos indicus (BI) and Bos taurus x Bos indicus heifers submitted to a synchronization of ovulation protocol. In Chapter 2, pubertal and prepubertal BI and CR heifers were submitted to the reproductive program proposed by Rodrigues et al. (2014) and a group of pubertal heifers were synchronized with the standard TAI protocol. In Chapter 3, pubertal and prepubertal BI and CR heifers were submitted to the reproductive program at the age of 12 months. In Chapter 4, was evaluated the effects of progesterone concentration at Day 9 of the TAI protocol and treatment with eCG in BI and CR heifers. In the experiment of Chapter 2 a greater number of BI heifers were pubertal at the beginning of the experimental period than CR heifers. The induction rate did not differ between BI and CR heifers. Breed of the heifers impacted pregnancy rate to TAI in Farm 1, but not in Farm 2. Heifers that did not respond to the induction protocol had lower pregnancy rate when compared to the others experimental groups. In the experiment of Chapter 3, the CL presence on D0 did not differ between breeds. Independent of the genetic group heavier heifers were more likely to have a CL on D0. There was an effect of CL presence at D0 on P/AI vs. Without CL. The interaction between CL presence on D0 and genetic group did not affect P/AI, and BI heifers had lower P/AI in comparison to CR heifers. An interaction between CL presence on D0 x weight was detected for P/AI. In heifers with CL, the weight did not have effect on P/AI; however, in heifers without CL, heavier heifers were more likely to become pregnant. In the experiment of Chapter 4, the progesterone concentration that has more sensibility and specify for pregnancy at Day 9 was 2.03 ng/mL. Follicle diameter at D9 was greater for CR heifers than BI heifers and in Low P4 compared to High P4. The follicle diameter at D11 tended to be greater for Low P4 than High P4. Probability of pregnancy was negatively associated with P4 level at Day 9. Ovulation rate was greater for eCG compared to Control. Crossbred heifers had greater conception rate and greater pregnancy rate than BI. LOW P4 heifers have greater conception and pregnancy rate than HIGH P4. In conclusion, it is possible to induce first ovulation in BI and CR heifers followed by the TAI protocol with satisfactory pregnancy rates in heifers from 12 to 27 months old, after puberty induction, if the nutritional requirements are achieved.
Descrição
Palavras-chave
Bos indicus, Bos taurus x Bos indicus, IATF, Novilhas, Puberdade