There have been limited reports on mastication speed during cattle rumination. The objective of this study was to establish a method to detect mastication speed based on data obtained during rumination through the use of a 3-axis accelerometer attached to the neck. A 3-axis accelerometer was attached to 6 dry Holstein cattle. When rumination behavior was observed, the accelerometer and the high-speed camera simultaneously recorded acceleration at the neck and moving image of the head movement. Based on the number of mastication movements recorded on video, mastication speed A was calculated. Data obtained from the 3-axis accelerometer were analyzed with fast Fourier transfer algorithm and identified as mastication speed B. The vibration of the neck recorded in the accelerometer during rumination was considered as mastication movement. Using Bland-Altman plot analysis, the mean difference between mastication speed A and mastication speed B was 0.041 s/bite, and the 95% limits of agreement ranged from -0.080 to 0.161. Since mastication movement occurred periodically, it was possible to detect the movement using spectrum analysis, as mastication speed B. Although there were some differences between calculated speeds and speeds obtained from spectrum analysis, there was clinical compatibility between mastication speed A and B. This study showed the feasibility of establishing a detection method for mastication speed during rumination, which might provide a basic procedure for studying the purpose of mastication and the variable factors involved.
Keywords: 3-axis accelerometer; cattle; mastication speed; rumination; spectrum analysis.
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