Fixed-time artificial insemination with estradiol and progesterone for Bos indicus cows I: basis for development of protocols

Theriogenology. 2009 Jul 15;72(2):179-89. doi: 10.1016/j.theriogenology.2009.02.010. Epub 2009 Apr 2.

Abstract

Five experiments were conducted on commercial farms in Brazil aiming to develop a fixed-time artificial insemination (TAI) protocol that achieved pregnancy rates between 40% and 55% in Bos indicus cows. These studies resulted in the development of the following protocol: insertion of an intravaginal device containing 1.9 g of progesterone (CIDR) plus 2.0mg im estradiol benzoate on Day 0; 12.5mg im dinoprost tromethamine on Day 7 in cycling cows or on Day 9 in anestrous cows; CIDR withdrawal plus 0.5mg im estradiol cypionate plus temporary calf removal on Day 9; TAI (48h after CIDR withdrawal) plus reuniting of calves with their dams on Day 11. Reduced dose of prostaglandin F(2alpha) (PGF(2alpha); 12.5mg im dinoprost tromethamine) effectively caused luteolysis. In cycling cows, fertility was greater when the treatment with PGF(2alpha) was administered on Day 7 than on Day 9, but in anestrous cows, no effects of time of the PGF(2alpha) treatment were found. Estradiol cypionate effectively replaced estradiol benzoate or gonadotropin-releasing hormone as the ovulatory stimulus, reducing labor and cost. In this protocol, CIDR inserts were successfully used four times (9 d each use) with no detrimental effects on fertility.

MeSH terms

  • Administration, Intravaginal
  • Animals
  • Cattle / physiology*
  • Dinoprost / administration & dosage
  • Estradiol / administration & dosage*
  • Estradiol / analogs & derivatives
  • Female
  • Gonadotropin-Releasing Hormone / administration & dosage
  • Insemination, Artificial / methods
  • Insemination, Artificial / veterinary*
  • Luteolysis
  • Ovarian Follicle / anatomy & histology
  • Ovulation Induction / methods
  • Ovulation Induction / veterinary
  • Pregnancy
  • Progesterone / administration & dosage*

Substances

  • estradiol 3-benzoate
  • Gonadotropin-Releasing Hormone
  • Progesterone
  • Estradiol
  • estradiol 17 beta-cypionate
  • Dinoprost