Page 108 - The Welfare of Cattle

sense and sensIbILItY 85

good at localizing sound, as is the case with some livestock species, including cattle (Heffner &
Heffner, 1992a). When animals hear a sound the subsequent response is to orient to the sound with
the best part of the visual field. In humans, this would be the fovea which does not have a large field
of vision (several degrees so the sound localization must be fairly accurate). In cattle, the best
field of vision is in the horizontal streak which encompasses a large angle and therefore the sound
localization can be more general, just orienting them to the general direction. When working with
cattle observe their ears and their subsequent head orientation to observe this response to a noise.
Overall, noise is a critical component of animal handling both because humans use noise to garner
the attention and response of cattle but also that the noises that come along with handling impact
cattle behavior and physiology, not always in a positive manner.

the BOVINe tOUCh—SOMatOSeNSatION

When thinking about the sense of touch what often comes to mind is how we as humans use our
hands to understand our environment by determining what things are, based on how their texture
and weight feel, determining the temperature of something, or responding to pain. These types of
tactile signals combined with other external cues help humans understand and interact with their
surroundings. Humans obviously use their hands extensively to touch things and as cattle are not
able to access the tactile world the same way as humans do they rely on other methods of gathering
tactile information, primarily doing so with their noses and mouths. Cattle use touch and cutaneous
sensitivity in a number of ways to both gain information about and respond to their environment. In
cattle, touch plays a role in exploratory behavior, in sensing and responding to aversive stimuli, and
in communication between herd-mates.

how Do Cattle Feel touch?

Skin receptors detect pressure, movement, temperature, and some damaging pathological condi-
tions such as inflammation—and this is how cattle feel “touch.” The cattle sense of touch is varied in
that the sense provides cattle with feedback to a range of different types of mechanical stimuli. The
somatosensory system of cattle, and mammals in general, is able to differentiate between noxious
stimuli that cause pain and innocuous or pleasant stimuli. In the skin, there are mechanoreceptors,
thermoreceptors, and nociceptors. There are five different types of mechanoreceptors: two found in
the superficial skin and three found deep in the skin. The receptors are actual nerve endings that have
specialized areas on the cell membranes that respond to mechanical distortion. There are several dif-
ferent kinds of thermoreceptors, some that respond to innocuous cool and warm stimuli and others
that respond to heat and cold that are nociceptors, responding to painful/noxious stimuli. The somato-
sensory system is a complex network delivering varying sensations to the brain. Mechanoreceptors
differ in surrounding tissues (which alters the response identified), adaptation to stimuli (slow or fast),
and the receptive field of the receptor (Møller, 2003). In the somatosensory cortex of the brain, there
is a “map” of the body as neurons are anatomically organized by the part of the body to which they
are connected. The representation of the body surface is not uniform. For example, in humans the
area dedicated to the fingers, hands, and face are much larger than the rest of the body. Considering
what is known about cattle, and how they “touch” their environment, the mouth, nose, and tongue
would have a larger representation in the somatosensory cortex than other parts of the body.

touch between herdmates

Tactile interactions, such as grooming, play a critical role in forming and stabilizing the social
networks of many species, including cattle (Gutmann, Špinka, & Winckler, 2015). Allogrooming