Figure 1.

Broiler behavioural changes over development. (a) Rapid decline in activity occurred between 0.321 and 0.911 kg (y = −15.98x + 18.940) while no further decreases were detected in heavier birds (y = −0.08702x + 4.465). Activity ± SEM for data collected on a commercial farm is denoted by asterisks. (b) Mean walking speed decreased until broilers reached 0.816 kg (y = −0.05549x + 0.1457), after which no further significant decline in speed was detectable (y = −0.001872x + 0.09885). (c) Peak walking speed initially decreased rapidly (y = −2.184x + 1.906) followed by a slower decline (y = −0.01996x + 0.4126).