The five senses
Vision is the foremost sense in cattle and is responsible for about half of the
sensory information they receive from their surroundings. Cattle have a 330°
vision, of this visual area, they have binocular vision for a limited area in front of
them. This is where they will have the clearest vision and ability to judge depth or
distance. In order to get the best possible vision, cattle will lower their head and
face the incitement of interest front on.
The rest of their visual field is monocular. This large monocular area is very
good for detecting predators, but they cannot judge distance here well. Because of
this poorer depth perception here, it is best to approach a cow from the side, but
moving at a slow pace. This will not spook the cow and allow you to approach
more closely than front on.
The remaining area around the cow is referred to as the blind spot. This is the
area directly behind the cow’s tail. If you approach the cow from her blind spot she
will not know you are there. Suddenly moving into or out of this position can upset
the animal and lead to flighty and erratic behaviour.
Cattle are less able to differentiate objects that differ in light intensity and
cannot see red colours as well as humans. This increases their colour contrast,
making shadows look more extreme compared to how we perceive them. Paired
with limited depth awareness, a block of shadow can look like a hole in the ground
to cattle. Shadows, very bright light and sparkling reflections will distract or slow
down cattle investigating their surroundings, often upsetting the smooth flow of
cows in a laneway. Cattle are also motivated to move from areas of low light to well
lit areas. Conversely, they will avoid moving from well lit to dark areas.
Taking cattle’s visual sense into consideration is very important when trying to
move them. In both free moving and tethered cattle, moving them can be much
easier if lighting is even, the area free of distracting and unfamiliar objects, and
you don’t make sudden, significant movements.
Cattle are very sensitive to high frequency sounds and have a wider range of
hearing than humans (a human’s auditory range is from 64 to 23 000 Hz, cattle’s
from 23 to 35 000 Hz). Despite having a greater range of auditory detection than
people, cattle have greater difficulty in locating the origin of sounds and will use
their sight to assist them determine the source. High pitched noises such as
whistling are also unpleasant to cows. Intermittent sounds such as clanging of
metal (e.g. gates), shouting and whistling can be particularly stressful, especially if
they are sudden and at a loud volume.
Due to their evolution as prey animals, cattle have a very acute sense of smell.
Cattle select their feed on the basis of smell and can detect odours many kilometres
away. They will avoid places containing urine from stressed animals, and for this
reason may be reluctant to enter places where cattle have been previously handled
such as raceways and cattle crushes. They dislike the smells of dung and saliva, so
when housed, their feeding area needs to be kept clean and smell fresh, not
contaminated with dung, saliva or exudate from other cows’ noses. Herd hierarchy
is strongly linked to smell, as shown by studies where the social order among cows
was unaltered by blindfolding them.
As well as a sensitive nose, they have an additional olfactory sensitive organ,
called the vomeronasal organ, on the roof of their mouth. The reception of odours
by this organ is used for the reinforcement and maintenance of sexual interest.
When seeking and finding a suitable cow on heat, this is characterised by the
‘flehman expression’ in mating bulls, in which the head is directed upwards with
the mouth ajar, the tongue flat and the upper lips curled back. This is thought to
aid odour sampling by allowing air to contact the roof of the mouth during
inhalation. Bulls appear to increase their olfactory behaviour about four days
before cows show signs of oestrus.
The production and detection of pheromones is another way cattle seek out
suitable stock for mating. For this reason, cows on heat spend much time sniffing
and licking the anal and vaginal areas of other cows. Other pheromones convey
fear. Cattle respond to pheromones produced in fearful situations by increasing
their own physiological stress response and fear behaviours. Cattle are also
sensitive to the odours of potential predators, like dogs, spending more time
sniffing the air and in cautious movement. In comparison to humans, cattle are
able to detect much smaller differences in odour concentration.
There are four primary tastes identifiable in cattle. These are:
● sweetness (associated with energy supply)
● saltiness (associated with electrolyte balance)
● bitterness (assists to avoid toxins and tannins that reduce the nutritive value of
● acidity (linked to pH balance).
The taste receptors are located in specific areas of the tongue, with differences
between cattle and humans in their taste discrimination, sensitivity and location
on the tongue. Cattle have two to three times as many taste buds as humans, and
so are more sensitive to tastes. Cattle can be apprehensive when it comes to eating
novel food – feed with unfamiliar tastes and smells. For example, they need
artificial sweeteners to mask bitter tastes such as zinc in water.
Skin receptors are used to detect pressure, movement, temperature and some
damaging pathological conditions such as inflammation. Humans have increased
sensitivity in their fingertips whereas cattle often use their extended mouth as a
sampling tool in exploratory situations.
Cattle perceive extreme ambient temperatures, relative humidities and/or wind
speed through thermoreceptors, skin dryness (particularly in the throat and nasal
passages) and mechanoreceptors. They learn their comfort or thermoneutral zones,
above and below which they must use physiological processes to sustain their core
body temperatures. They then modify their behaviour accordingly, such as seeking
cooler locations during hot weather to find more favourable microclimates. As the
lower critical temperature of adult cows is −23°C, they are rarely affected by cold
stress. Heat stress is a common problem, at 21°C cattle increase their respiration rate,
and at 25°C, above which they reduce feed intake to reduce metabolic heat……….