## 3 Results and Discussion
_rufa_ eggs submitted to several temperature regimes during storage and incubation, as well as the value (10.0%) reported by [PERSON] and [PERSON] [12] for red-legged partridge eggs submitted to different turning regimes during storage before incubation. No reference was found in the literature describing, in this species, the potential effect of egg contact on weight loss during incubation. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multicolumn{1}{c}{**Sibling Contact Regime**} & \multicolumn{2}{c}{**Number of Eggs**} & \multicolumn{1}{c}{**Fertility 1**} & \multicolumn{1}{c}{**Hatchability 2**} & \multicolumn{1}{c}{**Hatchability of the Fertile Eggs 3**} \\  & **Incbudated** & **Fertile** & **Hatched** & **(\%)** & **(\%)** & **(\%)** \\ \hline Without contact & 49 & 43 & 34 & 87.8 & 69.4 & 79.1 \\ Contact during incubation phase (1–20 days) & 49 & 43 & 33 & 87.8 & 67.3 & 76.7 \\ Contact during hatching phase (21 days-hatching) & 49 & 45 & 36 & 91.8 & 73.5 & 80.0 \\ Permanent contact (1 day-hatching) & 49 & 45 & 35 & 91.8 & 71.4 & 77.8 \\ Total & 196 & 176 & 138 & 89.8 & 70.4 & 78.4 \\ \(p\)-Value & & & & 0.828 & 0.921 & 0.984 \\ \hline \hline \end{tabular}  
* Percentage of incubated eggs that were fertile; 2 percentage of incubated eggs that hatched; 3 percentage of fertile eggs that hatched.  
\end{table} 
Table 1: Fertility and hatchability of red-legged partridge eggs according to the sibling eggs contact regime during the incubation process. The mean incubation period lasted 23.08 days (Table 4), a slightly lower value than the 23.20-23.70 day period reported for the red-legged partridge under artificial incubation [8; 9; 10; 11; 12]. It was in close agreement with the 23 day modal duration for the incubation length reported by [PERSON] et al. [8]. Incubation length was influenced by the sibling contact regime during the incubation process (\(p<0.001\)), being shortened when the eggs were in contact during the incubation with respect to the eggs without contact (Table 4). Thus, eggs without contact during the whole incubation process had an incubation length (23.50 days) within the interval described in literature for the artificial incubation of red-legged partridge eggs. This can be explained by the typical handling of _A. rufa_ fertile eggs during artificial incubation in most game farms, which involves incubating them without contact until the transference from the incubator machine to the hatcher usually on day 20 or 21 of incubation [34], and then placing them in the hatcher trays without paying specific attention to whether they are in close contact or not. In the present trial, eggs kept in contact during either of the two phases of incubation (1-20 days and 21 days-hatching) showed a shorter incubation length, hatching earlier (22.74 days) in the treatment in which eggs were in permanent contact throughout the entire incubation. Furthermore, eggs kept in contact during the hatching phase hatched within a brief interval of 24 h, during a narrow window between days 22.5 and 23.5 of incubation (Table 4 and Figure 1), and with shorter dispersion than that observed for eggs from the other treatments, showing the minimum variance (0.097; \(p<0.01\)) and the lowest coefficient of variation (1.35) for the incubation length. Studies on the artificial incubation of _A. rufa_ eggs demonstrate that hatching can begin on day 21.5 and end on day 26 from the start of incubation, within a variable interval that might last up to 4 days as a function of the incubation conditions [8]. Accordingly, the shorter hatching dispersion interval displayed by the eggs maintained in contact during the hatching phase is an interesting finding because it could allow red-legged game farms to improve hatching synchronization, a desirable situation to simultaneously extract the whole 1 day old chick batch from the hatcher, thus minimizing extraction queues. This mechanism optimizes 1 day old chick