Responses of dairy heifers to the visual cliff formed by a herringbone milking pit: Evidence of fear of heights in cows (Bos taurus).

Abstract

The ability of cows (Bos taurus) to perceive depth has never been experimentally investigated. If cows can perceive depth, the milking pit in commercial milking facilities may be fear provoking for dairy cows, as past research has shown that most land-dwelling species possess an instinctive fear of heights. In the current study, 12 dairy heifers (1-year-old cows) were exposed to a milking pit (depth-exposed group) and 13 heifers (control group) were exposed to a standard change in the environment while they moved through a milking facility over a 5-day treatment period. Heifers in the depth-exposed group showed a higher heart rate (p < .05) and stopped more often (p < .05) than did those in the control group; persistence of heart rate but not of behavioral responses on repeated exposures indicated that some habituation to the depth stimulus had occurred. Depth exposure had no effect on cortisol concentrations or on ease of handling. These results indicate that heifers responded differently to a change in depth than they did to a standard change in the environment and provide evidence of both depth perception and acute fear of heights in cows.

Behavioural Tests Reveal Severe Visual Deficits in the Strictly Subterranean African Mole‐Rats (Bathyergidae) but Efficient Vision in the Fossorial Rodent Coruro (Spalacopus cyanus, Octodontidae)

“…Being based on the inherent fear of heights, it involves no pre-traininganimals spontaneously avoid descending over a vertical edge to a surface which appears to be far away. Indeed, avoidance of the deep side of the cliff has been reported in diverse animals, including rats, cats, sheep, pigs, goats, cows, chicken and turtles (Walk & Gibson 1961;Arnold et al 2007). Here, we observed clear avoidance behaviour in the surfacedwelling mouse and fossorial coruro, providing evidence of both depth perception and acute fear of heights in these rodents.…”

“…Indeed, avoidance of the deep side of the cliff has been reported in diverse animals, including rats, cats, sheep, pigs, goats, cows, chicken and turtles (Walk & Gibson ; Arnold et al. ). Here, we observed clear avoidance behaviour in the surface‐dwelling mouse and fossorial coruro, providing evidence of both depth perception and acute fear of heights in these rodents.…”

Determination of a stray voltage threshold in Holstein heifers, influence of predictability and past experience on behavioural and physiological responses

“…For higher voltages (3 and 5 V), no further physiological differences were observed, which could be explained by three hypotheses. Firstly, heifers may have quickly habituated to the application of voltage as previously observed in a case of mild stress by Andrade et al (2001) after repeated handling and Arnold et al (2007) after exposure to noise. Secondly, at 3 and 5 V, heifers have had much more experience of voltage, and the startling and novel components of the electrical stressor were therefore not present any more.…”

A review of factors affecting the welfare of weaned replacement heifers in pasture-based dairy production systems

“…The milking parlour and its procedures are novel to heifers. Behaviours indicative of fear are observed when heifers are exposed to the visual cliff formed by a herringbone milking pit and milking facility noises, even without close human contact and imposition of milking procedures (Arnold et al 2007a(Arnold et al , 2007b. Cortisol concentrations are higher during the first milking of barn-housed primiparous cows in a tandem milking parlour compared with milking on Days 4 and 130 of lactation (Van Reenen et al 2002), and <40% of pasture-based heifers eat in their first milking in an automatic milking system (AMS; Jago and Kerrisk 2011).…”