Abstract:

  n order to reduce estrus synchronization cost, utilization of residual progesterone (P4) in the used controlled internal drug release (CIDR) device upon sanitization can be possible. Two datasets were compiled from 8 and 7 research articles involving 3434 (2653 heifers + 771 lactating cows + 10 ovariectomized cows) and 7301 cattle (3879 heifers + 3422 lactating cows) to evaluate blood P4 concentration and conception rate, respectively, in response to repeatedly used CIDR devices after sanitization via autoclaving and disinfection. As the number of CIDR usages increased, blood P4 concentration decreased linearly (y = -0.484X + 3.135, R2 = 0.99, P < 0.001). Blood P4 concentration (1.52 vs. 2.20 ng/mL; P < 0.002) and conception rate (40.76 vs. 32.96%, P < 0.05) for lactating cows were lower than those for heifers. The sanitization method did not affect blood P4 concentration, but reused CIDR device subjected to disinfection was associated with reduced conception rate. In summary, depending upon the initial P4 load (1.38-1.90 g), the CIDR device could be used twice in lactating cows and four times in heifers after autoclaving to achieve target blood P4 concentrations.

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