Ciência e Tecnologia Veterinária

The Effect of PGF_2α, GnRH, E₂ or Antibiotics on the Intrauterine Environment and Reproduction in Holstein Dairy Cows with Retained Placentas

Abstract

Kazuyuki Kaneko

PGF2α, GnRH, estradiol (E2), or antibiotics were given to dairy cows with retained placenta after parturition to establish the most suitable treatment to prevent the development of endometritis. One hundred and seventy five parous Holstein cows with retained placenta were allocated to into six treatment groups, and groups were given PGF2α, GnRH, E2, or antibiotics at 30 or 45 days after parturition. The intrauterine perfusion fluid was collected at 60 days after parturition, and a bacteriological and cytological examination was conducted. Reproductive performance was also investigated. The detection rate for Trueperella pyogenes in the intrauterine perfusion fluid in each group ranged from 0% to 16%, and T. pyogenes was not isolated in cows that were given PGF2α or E2. The percentage of neutrophils observed in the intrauterine perfusion fluid ranged from 37.8 ± 5.3 to 56.3 ± 4.7, and it was lowest in cows given PGF2α and highest in cows given GnRH. The mean number of days from parturition to initial insemination, the mean number of days from parturition to conception and the mean number of artificial inseminations required for conception ranged from 85.9 ± 5.5 to 102.7 ± 8.0, 103.8 ± 9.0 to 162.3 ± 18.6 and 1.5 ± 0.2 to 2.6 ± 0.3, respectively. All three parameters were best in cows that were given a combination of PGF2α and E2. The results suggest that administration of PGF2α or E2, or ideally both, might be a suitable treatment for cows with retained placenta. However, treatment with GnRH might delay the cleansing of the uterus.