Fig 1.
Illustration of the experimental settings.
A photo of the experimental pen (left) and a schematic drawing of the robot (right).
Fig 2.
Schematic drawing of experimental design.
“w/o” and “w/” are without and with, respectively.
Table 1.
Weekly floor egg rates and relative floor egg reduction.
Table 2.
Hen-day egg production, feed intake, and feed conversion ratio (FCR).
Fig 3.
Illustration of egg mass of different egg types.
Data were from 40–43 weeks of bird ages in flock 2. Values having different letters atop the bars are significantly different (n = 24), with significance level of 0.05, least square difference post-hoc analysis, and PROC MIXED statement.
Table 3.
Egg mass under the treatments.
Fig 4.
Live body weight (a) (n = 4) and litter moisture content (b) (n = 6) under the treatments. Data were only measured at the end of the experiments (43 weeks of bird age). ‘w/’ and ‘w/o’ represent with and without, respectively.
Table 4.
Footpad score and mortality.
Table 5.
Mean and coefficient of variations (CV) of serum corticosterone concentrations.
Table 6.
Means of bone breaking force, fresh bone weight, dried bone weight, bone ash weight, and ash percentage under the treatments.
Table 7.
Coefficient of variations (CV) of bone breaking force, fresh bone weight, dried bone weight, bone ash weight, and ash percentage under the treatments.
Table 8.
Hen time spent in nest boxes under the treatments.
Fig 5.
Frequency of number of birds simultaneously using a nest box with regard to different sections of time: (a) during 7:00 to 13:00 in weeks 35–38; (b) during 7:00 to 13:00 in weeks 40–43; (c) in a day in weeks 35–38; and (d) in a day in weeks 40–43. ‘w/’ and ‘w/o’ represent with and without, respectively.
Fig 6.
Hourly time spent in nest boxes.
(a) From 6:00 to 21:00 in weeks 35–38; (b) from 6:00 to 20:00 in weeks 35–38; (c) from 6:00 to 21:00 in weeks 40–43; and (d) from 6:00 to 20:00 in weeks 40–43. Each value is the average of 4 values, and shading areas represent pooled standard errors of the means. ‘w/’ and ‘w/o’ represent with and without, respectively.
Fig 7.
Example pictures of hen-robot interactions for a pen with two-week robot running in phase 1 (weeks 35–38).