Recorded sounds associated with feeding did not affect feeding behavior of lambs

This study was designed to determine whether periodic exposure to pre-recorded sound associated with feed delivery and consumption would alter feed intake or feeding pattern of lambs provided with fresh feed once daily. Thirty cross-bred lambs were randomly assigned to 6 pens. The trial lasted 44 days (30 July to 11 September 1982) and consisted of a 4-day acclimation to test facilities, and then cycles of 4 days without sound stimulation followed by 4 days with sound stimulation. Sound stimulation consisted of 6-min broadcasts, every 3 h, of sounds associated with feed delivery and eating. Lambs were observed continuously for 24 h on 3 days when lambs were subjected to sound stimulation and 3 days when they were not. The recorded sound stimulation affected neither feed intake nor feeding behavior. Lambs largely ignored the recorded sounds, and total feed intakes during 20 sound-stimulated vs. 20 non-sound-stimulated days were 1234 vs. 1240 kg, respectively. There was a rhythmic feeding pattern at 1–2-h intervals, synchronously throughout the barn, and this was not affected by the 6 min of sound stimulation at 3-h intervals. There were no major peaks in feeding activity except after the offering of fresh feed in the morning. Feeding activity did not change with sunrise or sunset, and peaks of eating activity were distributed at even time-intervals throughout the 24 h. The overall means per lamb for the total time spent eating, the number of eating bouts (separate eating incidents), the average time eating per bout and the number of drinking episodes across the 6 observation days were 118.8 min, 22.6 times, 5.5 min and 9.6 times, respectively.