Adaptation to tethering in yearling dairy heifers assessed by the use of lying down behaviour

This study investigates how the lying down behaviour is affected during the first weeks after tethering. Forty-eight dairy heifers in four trials were brought in from pasture and housed individually in straw-bedded pens prior to the experiment. During the experimental period of 24 days, the heifers were either tethered in stalls with concrete floor during all 24 days, the last 10 days, the last 3 days, or stayed in the pens for the whole period (control). At the end of the experimental period, the behaviour of all heifers was video-recorded during 24 h. The number of investigations of the lying surface per lying down was largest (P < 0.001), and the latency to Lie down was longest(P < 0.001) in heifers tethered for 3 days. Heifers tethered for 3 days had fewer lying periods per 24 h (P < 0.001), and the lying down movement took the longest time in these heifers (P < 0.001). However, the number of lying interruptions per lying down was higher in heifers tethered for 3 and 10 days compared to control heifers, while heifers tethered for 24 days was in between (P < 0.001). Heifers tethered for 3 days appeared to have the greatest problems and loose heifers appeared to have fewest problems with lying down. The results suggest that heifers have problems lying down in tie-stalls, especially shortly after tethering, and that full adaptation to tethering does not occur within the time investigated. (C) 1999 Elsevier Science B.V. All rights reserved.