Change in the incidence of stillbirth in Japanese Black cattle during the animal movement restrictions and suspended insemination.

We aimed to characterize the change in the incidence of stillbirth (IS) in Japanese Black cattle during and after animal movement restrictions and suspended insemination because of a foot-and-mouth disease (FMD) outbreak in Miyazaki Prefecture in 2010. Calving data from 2006 to 2018 were collected from approximately 900 farms. Post-FMD period was divided into three based on the median IS per month (1.80%): period 1 (May 2011 to February 2013), period 2 (March 2013 to August 2015), and period 3 (September 2015 to December 2018). The ISs were similar during the Pre-FMD period and Post-FMD period 1, then substantially decreased during Post-FMD period 2 (p < .05), before returning to the value before the FMD outbreak period during Post-FMD period 3. Compared with the Pre-FMD period, Post-FMD period 1 was associated with a higher proportion of calvings by primiparous cows and Post-FMD period 2 was associated with a smaller number of calvings per month (p < .05). There were high ISs in primiparous cows during the Pre-FMD period, Post-FMD period 1, and Post-FMD period 3 (p < .05), but not during Post-FMD period 2. In summary, after the animal movement restrictions and suspended insemination introduced because of the FMD outbreak, the IS temporarily decreased and consequently returned to the pre-FMD level.