Effect of the disinfection treatment of used intravaginal devices on the concentration of progesterone on cows under dry tropical conditions

The objective of the study was to compare the effect of disinfection/cleaning of CIDR devices on serum progesterone concentrations (P4) in Brown Swiss x Zebu cows, which received during eight days a new intravaginal device (CIDR; T1), used device, sterilized by autoclave (T2) or a used device, disinfected with chlorine (T3). A complete randomized design with three replicates per treatment was applied. The used CIDR devices were used previously in cows. Blood samples were collected at 0, 15, 30 min, as well as at 1, 3 and 6 h and then each 12 h until day 10, with respect to the moment of the insertion of the CIDR. The P4 concentration was determined by radioimmunoassay. Mean concentrations of P4 were similar among treatments (T1, 1.7 +/- 0.9 ng/mL; T2, 1.31 +/- 0.65 ng/mL; and T3, 1.33 +/- 3.19 ng/mL; P<0.05). In conclusion, the process of disinfection/cleaning of the CIDR devices did not affect the availability of progestogen, therefore the CIDR could be used for estrous synchronization.