The average number of daily pig movements was 682, with Thursdays being 2.44 times higher than the average, related to preparation for the higher demand over the weekends and the higher activity of markets (Fig. 3A). In Fig. 3B, we plot the frequency of movements by week. Furthermore, over the years, the mean number of weekly movements grew from 3,599 in 2017 to 5,973 in 2019, which is supported by an increasing trend over time (S=144, p<0.01 Mann-Kendall test) and the detection of a change point (p=<0.001) on week 73 corresponding to May 2018 (K on Fig. 3B), related to the adoption of stricter vaccination and movement policy. Cultural and political influence affected the network, identified by weekly reductions from the average of movements; -53.8% due to the celebration of Carnival holiday (a in Fig 3B), 14% due to a extended national holiday (b in Fig 3B) and 73% due to road blockades during a national strike led by indigenous groups (c in Fig. 3B).
Figure 3. Representation of pig movements in different time aggregations. (A) Box plots of the number of movements grouped by day of the week. (B) Movements grouped by week and filled by days of the week; Pettit’s change point (k) at week 72, and highest reductions in the weekly movements marked with letters a (carnival holiday), b (extended holiday) and c (national strike).