Ovarian dynamics and milk progesterone concentrations in cycling and non-cycling buffalo-cows (Bubalus bubalis) during Ovsynch program

Theriogenology. 2007 Jul 1;68(1):23-8. doi: 10.1016/j.theriogenology.2007.03.011. Epub 2007 May 4.

Abstract

The objective was to evaluate ovarian dynamics and progesterone concentrations in cyclic (CYC, n=10) and non-cyclic (NCY, n=8) buffalo-cows during Ovsynch program. All cows received GnRH on day 0, PGF2alpha on day 7, and GnRH on day 9, and AI 14 h later. Ovarian structures were monitored by ultrasound and milk samples were collected for progesterone (P4) analysis. The first GnRH resulted in ovulation in CYC (90%) and NCY (62.5%) cows. By day 7, almost all cows had large follicle and lutein tissue. Luteolytic responses to PGF2alpha were 80 and 87.5% for CYC and NCY cows, respectively. Following second GnRH, ovulation occurred in 80% of CYC and 100% of NCY cows. Ovulation began earlier (12 h following second GnRH) and extended for longer (36 h) in NCY cows, when compared to CYC cows (36 and 12 h, respectively). The mean P4 levels increased from days 0 through 7 in CYC and NCY cows and levels were higher in CYC group. Conception rates were 60 and 37.5% in CYC and NYC cows, respectively. Early and asynchronous ovulation and luteal sub-function seemed to be a problem in NCY cows. Inseminating NCY cows twice, at 0 and 24 h of the second GnRH is recommended.

MeSH terms

  • Animals
  • Buffaloes / metabolism
  • Buffaloes / physiology*
  • Dinoprost / pharmacology
  • Estrus / drug effects
  • Estrus / metabolism*
  • Estrus Synchronization / drug effects
  • Female
  • Gonadotropin-Releasing Hormone / pharmacology
  • Insemination, Artificial / veterinary
  • Milk / metabolism*
  • Ovary / diagnostic imaging
  • Ovary / drug effects
  • Ovary / metabolism*
  • Ovulation / physiology
  • Pregnancy
  • Pregnancy Rate
  • Progesterone / metabolism*
  • Ultrasonography

Substances

  • Gonadotropin-Releasing Hormone
  • Progesterone
  • Dinoprost