## 3 Results and Discussion
### Phase Space: Variability in EST by Transport Stage  
Table 3 summarizes the areas and centroids of the phase space diagrams per animal per transport stage. The highest centroids (34.1 \({}^{\circ}\)C and 35.5 \({}^{\circ}\)C) corresponded with Stage1-Air and Stage3-Rest, while all road transport stages had centroids close to 33.5 \({}^{\circ}\)C. Stage1-Air and Stage3-Rest had the highest average areas in the phase space (85.7 and 67.1 \({}^{\circ}\)C\({}^{2}\), respectively). The average area in Stage3-Rest was 22% lower than Stage1-Air, while the duration of the Stage3-Rest was almost double that of Stage1-Air. Thus, we can use the area of the phase space diagrams to compare the thermal variability among stages of different duration, where the value of the area was not correlated with the duration of the times series considered. During road transport (Stages 2 to 5), the thermal variability in terms of areas was between 67% and 43% lower than Stage1-Air. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Pig Number** & **Area (\({}^{\circ}\)C\({}^{2}\))** & **Centroid (\({}^{\circ}\)C)** \\ \hline
1 & 121.6 & 33.7 \\
2 & 93.4 & 35.0 \\
3 & 111.3 & 34.8 \\
4 & 124.2 & 35.3 \\
5 & 138.2 & 33.6 \\
6 & 111.6 & 33.1 \\
7 & 97.9 & 35.1 \\
8 & 143.4 & 33.8 \\
9 & 99.1 & 32.8 \\
10 & 74.1 & 34.8 \\
11 & 132.8 & 34.3 \\ Mean & 113.4 & 34.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Summary of EST centroid value and area obtained using the phase space representation. Figure 4: Summary of the mean EST per pig over the whole journey. The mean EST of each pig is represented by a circle, and the interval is represented by a line extending from the symbol. The highlighted Pig Number 1 (in blue) is not significantly different from the rest of the animals (in gray). Figure 5: Phase space representation of EST for Figs 8 (female, Group 3) and 10 (male, Group 4) throughout the journey (f = 5). Figure 6: Results from the multiple comparison of group mean phase space areas. Each group (**a**): sex; (**b**): age group mean is represented by a circle, and the interval is represented by a line extending out from the symbol. Red color indicates it is significantly different from the blue one (\(p<0.05\)), while gray color indicates no significant differences with the highlighted group (in blue). In Figure 8, we show the medians and the interquartile ranges of the areas of the phase space diagrams per transport stage. Stage1-Air had the highest median with the lowest interquartile range, which indicates the variation in EST was the highest and also similar among all pigs. On the other extreme, Stage2-Road had the highest interquartile range, indicating that EST varied differently among pigs, with some being quite stable (e.g., Pig 10 with 13.1 \({}^{\circ}\)C\({}^{2}\)), while others were more variable (e.g., Pig 5 with 117.6 \({}^{\circ}\)C\({}^{2}\)). These results could be related to the position of the pigs on the vehicle since it has been shown that position affects the micro-environment in each pen and, as a result, also the skin temperature of the animals [15]. According to the ANOVA, there were significant differences among the areas for Stage1-Air compared with the road transport stages (F = 6.4, \(p\) = 0.0003).