Fig 1.
Broiler chickens housed in four environments.
(A) Control, (B) Hay bale, (C) Step platform, and (D) Laser lights.
Table 1.
Experimental ethogram of recorded broiler chicken behaviors, based on [44].
Fig 2.
Presence or not of subclinical spondylolisthesis in broiler chickens’ backs at 43 days of age.
(A) Score 0: vertebrae found on their normal axis without compressing the bone marrow, (B) Score 1: vertebrae compressing the bone marrow.
Fig 3.
Frequency of observations (mean % ± SEM) of each behavioral category by treatment (C = control, HB = hay bales, SP = step platforms, LL = laser lights) across 2 time periods (09:00 and 15:00 h), n = 192 observations.
Frequencies of (A) resting behavior, (B) exploratory behavior, (C) comfort behavior, and (D) consummatory behavior. Means within behavioral category without a common superscript (a–c) differed at P < 0.05.
Fig 4.
Frequency of observations (mean % ± SEM) of each behavioral category by chicken age (in weeks) across two time periods (09:00 and 15:00 h), n = 192 observations.
Frequencies of (A) resting behavior, (B) comfort behavior, (C) exploratory behavior, and (D) consummatory behavior. Means within a behavioral category without a common superscript (a–e) differed at P < 0.05.
Fig 5.
Frequency of observations (mean % ± SEM) of behaviors associated with the provided hay bale by age (in weeks) across two time periods (09:00 and 15:00 h).
Sitting or resting by bale (n = 24), Pecking (n = 24), and Resting on top (n = 24). Frequencies without a common superscript (a-c) differed at P < 0.05.
Fig 6.
Frequency of observations (mean % ± SEM) of behaviors associated with the provided laser lights by age (in weeks) across two time periods (09:00 and 15:00 h), n = 24.
Frequencies without a common superscript (a-c) differed at P < 0.05.
Fig 7.
Frequencies (%) of broiler chickens by gait score (GS) at 21, 28, 35, and 42 days of age, n = 16.
GS 0: Healthy chickens that exhibited no abnormality when walking, GS 1: Chickens that exhibited difficulty walking in a way that was easily identifiable through observation, and GS 2: Chickens exhibiting severe issues walking [45]. Ages without an uncommon superscript (a–d) differed at P < 0.05.
Fig 8.
Proportion (%) of broiler chickens with subclinical spondylolisthesis score 1 (vertebrae compressed the bone marrow) at 43 days of age, n = 192.
C = control, HB = hay bales, SP = step platforms, LL = laser lights. Bars without a common superscript (a–c) differed at P < 0.05.
Table 2.
Performance (mean ± SEM) of broiler chickens between days 1–21, days 1–35, and days 1–42 of rearing, n = 16.
Table 3.
Yield (mean % ± SEM) of carcass, breast, wings, legs, back, breast fillet, boneless legs, and abdominal fat of broiler chickens slaughtered at day 43 of age, n = 16.