A technique for the measurement of synchronised feeding in miniature pigs: determination by means of Walsh-Fourier spectral analysis

摘要

In order to investigate feeding synchronization in miniature pigs, a computer-controlled laboratory setup has been developed, recording the feeding behavior of two pigs at a time for weeks. Since, this setup delivers time series with a binary data structure, and thus Fourier-Spectral analysis is difficult to perform, Walsh-Fourier Spectral analysis for ordinal or binary data was utilized. Synchronicity between pigs housed together was estimated by coherency values, determined for the highest sequences of the Walsh-Fourier power spectra. Feeding behavior was recorded in 12 pigs (26-50 kg) housed in pairs, in separate, but adjacent pens. Pigs were conditioned to operate feeders and feeding was recorded for two weeks. Pigs housed adjacent to one another showed an overlap in the dominant sequencies which was confirmed by high corresponding coherency values. Furthermore, pairs of pigs were matched according to age, weight and gender, and combined by chance. Compared to these pairings, coherencies were higher and more consistent in pigs housed in adjacent pens. If the data structure is binary, Walsh-Fourier Spectral analysis utilizing coherencies as a measure of correlation between the spectra has been shown to be a useful tool in the investigation of behavioral synchronization.