@article{oai:rakuno.repo.nii.ac.jp:02000254,
 author = {森田, 茂 and MORITA, Shigeru and 岡崎, 駿平 and OKAZAKI, Syunpei and 加藤, 寛之 and KATO, Hiroyuki and 上田, 宏一郎 and UEDA, Koichiro},
 issue = {3},
 journal = {Animal behaviour and Management},
 month = {Aug},
 note = {journal article, A wireless accelerometer is a useful device for developing an activity record of calves. The objective of this study was to test the wireless accelerometer for measuring the frequency of sucking in dairy calves. Four calves were reared in individual pens. The sucking duration and the number of sucking movements were determined from individual video data. The accelerometer was attached on the collar placed around the neck. A spectral analysis was used for estimating the frequency of sucking movement. Average duration of sucking was 219 seconds, the number of sucking movements was 473, and observed sucking frequency was 2.2 Hz. The average of estimated sucking frequency was 2.4 Hz. In 70% of cases, the difference between the observed and estimated was under 10%. The frequency of sucking movements correctly measured by an accelerometer. The duration of sucking and number of sucking movements decreased, and the frequency of sucking movement increased with days of age, but changes were very small in the frequency of sucking movement. The frequency of sucking milk of calves should be measured and characterized automatically by sensors with an accelerometer., 無線式加速度計が、子牛の動作を記録する機器の開発に利用されている。本研究では、無線式加速度計を用いて子牛の吸乳行動記録に利用し、子牛の吸乳行動の特徴を検討した。4 頭のホルスタイン種子牛を単飼した。子牛の吸乳時間と吸乳回数は、ビデオ記録から求めた。加速度計を首輪に装着し、得られたデータから、最大エントロピー法を用いて吸乳頻度を推定した。推定平均吸乳時間は219 秒であり、平均回数は473 回であった。観察された吸乳頻度は2.2Hz（回/ 秒）であった。主に上下の動作を含む方向での加速度変化から、吸乳頻度が推定でき、推定された吸乳頻度は2.4Hz であった。用いたデータ期間は、平均80 秒で、これは全吸乳時間の38.9％であった。全体の70％で、実測値と推定値の差が10％以内であり、加速度計で吸乳頻度が推定できることが示された。吸乳時間や吸乳回数は日齢とともに大きく変化するが、吸乳頻度の増加はわずかであった。},
 pages = {109--115},
 title = {Measurement of frequency of sucking in rubber teat-fed dairy calves using an accelerometer attached on the neck-collar},
 volume = {58},
 year = {2022}
}