Vocalizations and behavior of two commercial stocks of chickens

Vocalization and behavior comparisons were made between two commercial egg-laying stocks maintained under high intensity, battery-cage housing. Data obtained at approximately 35 weeks of age from both stocks in the same house showed significantly more pushes and steps in Stock B than in Stock A flocks. Also, the frequency range of vocalizations emitted was greater for Stock B than for Stock A pullets. This difference was attributed to an increased number of disturbance calls and shriek -like sounds called " baaks ".