Development and application of audio database for laying hens

Particular states of mood or emotion of laying hens may be accompanied by specific behaviors, vocalization being one of them. Taking advantages of non-invasive monitoring of sound analysis, relevant acoustic features and modern techniques will promote to establish a remote-monitoring platform for laying hens' management. State-of-art digitalization tools and database management technologies were used to the research of behavioral observation and audio analysis. The animals used in this experiment were 5 laying hens (Hy-Line Variety Brown, U.S. standard) and were housed in a feed anticipating condition. During 28 April-30 April 2012， the vocalizations of laying hens were recorded in early morning. A NI-PXI platform integrated with sound sensors were used for all the recordings. The acoustic features including duration of call, pitch, energy center of call, formants and the derivatives were derived using Adobe Audition v1.0 and Praat 5.3. All the features were calculated and written in audio database of laying hens (ADLH). In terms of egg laying, song and call of laying hens, the vocalizations were formed with repeated transient syllables at 7.8±2.0, 15.2±7.7 respectively. Significant differences (P<0.05) were found between duration of call, maximum and minimum frequencies of the verse. With reference to the syllable structure of the vocalizations of laying hens, the acoustic features including energy center, the first formant and the second formant were significantly differed. Pitch of the calls was in the range of 400-500 Hz. Occurrence of the song of laying hens was determined by their emotion and behaviors, and was characterized by walking (43.1%), searching (48.6%), and dust bathing (8.3%). Results indicate that analysis of vocalizations could be an indicator of different physiological conditions and behavior contexts of laying hens and may be an important tool for understanding communications among them. This study will offer an acoustic solution, automatic recognition and digital monitoring tools for laying hens' management.