## 3 Results and Discussion
### The Preference of Laying Hens between Nests Located on the Lower and Upper Levels  
It is important to compare the nesting behavior observed with the video assessment in the produced data of each group of hens to see how many eggs the hens laid in the upper and bottom nests. Therefore, the observations and the daily collected production data can confirm each other and allow conclusions to be drawn on a solid basis. The higher number of eggs in each nest can be used to determine the nests preferred by the hens [14]. Table 2 shows the total relative percentage of eggs laid in the nests of the bottom and upper levels during the 12 production months. The Commercial hybrid and Maternal  
Figure 5: Changes in the proportion of eggs laid in the litter and in the nest during the 12 months of egg production in the case of the different genotypes. genotype laid their eggs in one of the lower nests in a ratio slightly below three-quarters (72.2% vs. 71.4%, respectively), while slightly above a quarter (27.8% vs. 28.6%, respectively) in the upper level. The nest selection preference is clear, as nearly three times as many eggs could be collected from the lower nests as from the upper ones during the 12 months of production. The performance of the Patternal genotype differed from that of the other two tested genotypes in that 88% of the eggs were laid in the lower nests. Based on the nest selection preference, seven times more eggs were 'placed' on the lower level compared with the upper one (Figure 6). The results clearly show that the Patternal genotype mostly preferred the lower places as it laid its eggs here, which is also reflected in the choice of nest and the number of litter eggs, as this genotype is the one that laid its eggs to the greatest extent in the litter-covered scratching area. Figure 7 shows the changes in the proportion of eggs laid in the lower and upper nests during the 12 months of egg production, organized by the tested genotype. A clearly visible and clear trend can be observed, where each genotype produced more than 90% of the eggs collected in the bottom nests during the first month of production. \begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Genotypes**} & \multicolumn{3}{c}{**Distribution of Eggs (\%)**} \\ \cline{2-4}  & **Bottom Nests** & **Upper Nests** & **Prob.** \\ \hline Commercial hybrid & 72.2 b  & 27.8 & \textless{}0.001 \\ Patternal & 88.0 a  & 12.0 & \textless{}0.001 \\ Maternal & 71.4 c  & 28.6 & \textless{}0.001 \\ Prob. & \textless{}0.001 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The total ratios of eggs laid in the lower and upper nests during the 12 production months in percentages (%). Figure 6: The significant preference for bottom nests in the Patternal genotype. In the case of the Commercial hybrid and the Maternal genotypes, the use of the upper nests and the proportion of eggs that collected there gradually increased. This rose above 20% at the fifth month, then reached or approached 40% by the seventh month of production and maintained or even slightly increased this level towards the end of the study period. Practically, for these two genotypes, the proportion of eggs laid in the upper nests increased at the same rate, and at the eighth month, 45-47% of the eggs were laid in the upper nests, while 53-55% were laid in the lower nests. Based on our observations, the proportion of eggs laid in the bottom and upper nests of the Patternal genotype differed greatly from this trend, which is an eye-catching feature of the data. In the first month of egg production, 94% of the eggs from the Patternal genotype were collected from the lower nests, which not only stagnated, but sometimes even increased. This rate only dropped below 90% after the eighth month of production, but the rate of eggs collected from the bottom nests was only less than 80% in the last two months.