Physiological characterization of the postpartum period in four cattle breeds in the tropics of Colombia

Objective. To describe the postpartum period through reproductive parameters, progesterone levels and types of ovarian activity. Materials and methods. 63 females of the breed Holstein x Cebu (HC), Simmental x Cebu (SC), Romosinuano (R) and Cebu (C) were followed from weaning to confirmation of a second pregnancy, blood samples were taken to determine progesterone concentrations by Radioimmunoassay. For the analysis of the information statistical program SAS was used. Results. There were significant differences for age at first postpartum heat, except in the SC and HC groups, regarding the first heat postpartum weight, SC and C groups had higher growth rates, followed by R and HC groups. No significant differences were found for the interval from calving to first progesterone rise. The first postpartum ovulation was presented to the 34.45 days in the SC group, 83.24 in the HC, 46.13 in the R and 31.9 in C. The type of ovarian activity reflects the reproductive efficiency performance, the SC and HC groups had low conception rates, contrary to the R group, which presented an excellent conception rates and progesterone levels considered normal in more than 80% females. Conclusions. The analysis of the progesterone profiles offer a convenient method for monitoring ovarian activity, being able to accurately determined the acyclic duration, the time of ovarian activity resumption, presence of ovarian dysfunctions and finally the beginning and pregnancy maintenance.