Evaluation of used progestagen implants on pregnancy rate in beef cows

Authors

  • Décio Zuliani Maluf Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP
  • Alexandre Vaz Pires Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Departamento de Zootecnia, Piracicaba, SP
  • Ivanete Susin Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Departamento de Zootecnia, Piracicaba, SP
  • Rafael José de Carvalho Moreira Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP
  • Ed Hoffman Madureira Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Reprodução Animal, São Paulo, SP
  • Mario Binelli Universidade de São Paulo, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Reprodução Animal, São Paulo, SP
  • José Renato Gonçalves Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Estação Agrozootécnica Hildegard Georgina Von Pritzelwitz, Londrina, PR
  • Laisse Garcia de Lima Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Estação Agrozootécnica Hildegard Georgina Von Pritzelwitz, Londrina, PR
  • Clayton Quirino Mendes Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP
  • Marcos Vinicius Biehl Universidade de São Paulo, Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP

DOI:

https://doi.org/10.11606/issn.1678-4456.bjvras.2010.26847

Keywords:

Estrous cycle, Estrous synchronization, Norgestomet, Reproduction

Abstract

Two-hundred and twenty-one (78 suckling - 40 to 90 days and 143 not suckling ) Nelore (Bos taurus indicus) and crossbred Charolais (Bos taurus taurus) cows were used to evaluate the reutilization of progestagen implants to pharmacological control of the estrus cycle and ovulation on pregnancy rate. Cows were randomly assigned to one of three protocols for estrous synchronization and pre-fixed time artificial insemination (FTAI) was performed. In treatment 1 (T1; n = 73) cows were implanted with Crestar® (3 mg de norgestomet); in treatment 2 (T2; n = 75) cows were implanted with already used Crestar®, and in treatment 3 (T3; n = 73) cows received two Crestar® implants, also both previously used. All cows were injected with 2 mL of progesterone (25 mg/mL) + 1 mL estradiol benzoate (1 mg/mL i.m.) at the time of implants insertion, intramuscular (i.m). Implants were removed after eight days and 2 mL of Preloban® (150 µg de D-cloprostenol) were administered i.m. Twenty-four hours after implants removal, cows were injected with 1 mL (i.m.) of Estrogin® (1mg of estradiol benzoate). The FTAI was performed 54-56 h after implants removal. There was no difference (P >; 0.05) on cow's pregnancy rate among treatments. Pregnancy rates were 39.72, 34.21 and 36.98% for T1, T2 and T3, respectively. Progestagen implants reutilization (Crestar®) did not affected pregnancy rate in beef cows ready for reproduction.

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Published

2010-02-01

Issue

Section

UNDEFINIED

How to Cite

Evaluation of used progestagen implants on pregnancy rate in beef cows. (2010). Brazilian Journal of Veterinary Research and Animal Science, 47(1), 38-46. https://doi.org/10.11606/issn.1678-4456.bjvras.2010.26847