HOW DO THE CATTLE SEE?

For cattle, as for humans, sight is the dominant sense, from which they obtain about 50% of the information from the environment.

Sight is involved in social and physiological aspects: isolated cows suffer, they are social animals that need eye contact with their peers, since they are preyed upon animals the sense of the group reassures them. In addition, through sight, the pineal gland records the length of the daylight hours of the day and regulates the reproductive hormonal axis.

Nevertheless, cattle see differently from humans: they have a 330 ° vision, monocular at great distances; being a predated animal this allows it to graze and ruminate for hours, keeping the surrounding territory under control.

Several scientific studies have shown good visual sensitivity of cattle (strong perception of light stimuli), but reduced acuity (weak perception of details).

The lateral position of the eyes and the pupillary shape allow a wide field of vision: without having to move the head, the bovine can see practically everything that happens around it, with the sole exception of a very narrow area behind it.

Field of view

Knowing the visual field is important, for example, to approach them correctly, or from the side and slowly, thus avoiding triggering reactions of fear and therefore fickle, unpredictable and potentially dangerous behaviors. Even during handling operations it is essential to take into account that humans and cows have a different field of vision and, therefore, see different things.

Binocular vision

Binocular vision is a limited area in front of them and this should be taken into consideration as it limits their ability to perceive depth or distance.

The front visual zone includes a blind spot, as lines of sight cannot converge due to the lateral position of the eyes.

However, the long distance view is very clear, even if it takes time to focus. Cattle can distinguish different geometric shapes and their orientation.

Cattle only see a small area in front of them and cannot gauge distance and depth well. Certain configurations of passageways or gates can conflict with a cow's depth perception making it difficult to move the animal efficiently.

For example, a cow will not perceive an opening at right angles to the end of a corridor and the animal will avoid being moved in this direction since it does not perceive an escape or return route.

Vertical view

Due to their limited vertical vision and lack of ability to focus quickly, it is important to take into account that their perception of an obstacle differs from ours. For example, a shadow on the ground could be mistaken for a deep crevasse! It is therefore important to avoid obstacles on their path (real or presumed) such as small objects, changes in flooring and surfaces, drainage grids: in this case, allow the cow time to lower her head, focus on the obstacle and proceed again.

Perception of colors

Cattle in nature are more active at dawn and dusk so they are very sensitive to light, they are dazzled by bright light and are afraid of bright contrast: they are less able to discriminate objects that differ in light intensity and are unable to see the contrast of color, they perceive the most extreme shadows compared to how man perceives them. They have a discolored vision, they are able to distinguish the colors of the longer wavelengths (yellow, orange and red) much better than the shorter wavelengths (blue, gray and green).

Calves are able to discriminate between long (red) and short (blue) or medium (green) wavelengths, but have a limited ability to discriminate between short and medium.

As far as possible it is therefore good to maintain uniform lighting, reduce contrasts and reflective surfaces.

Perception of movement

Ocular anatomy produces variable visual acuity: the perception of dynamic movement is more detailed than what happens for human vision, but the vision of movement is distorted. This characteristic could explain the animal's fear of rapid movements and therefore the need for the farmer to move with slow and frequent movements.

the perception of dynamic movement is distorted so they are afraid of rapid movements which have a great effect in activating the amygdala, the part of the brain that controls fear.

It is therefore good to move with slow movements so as not to frighten them and not to be perceived as potential predators, as well as to pay attention to other details that can scare them, such as clothes hanging on fences, plastic objects in motion, the movement of the fan blades.

The flickering of the lamps commonly used to illuminate the stables can also disturb the animal.

Visual communication

A relevant concept also concerns how man is visually perceived by the animal. Studies show the existence of correlation between the speed of human movements and the agitation of the bovine during different production phases such as milking.

In other words: the more agitated the man when moving the cattle, the more nervous they appear.

Cattle employ visual ways of communication, to convey information to other group members during comparisons. Visual communication occurs mainly through head postures or body movements. The different positions indicate states of attention, excitement or aggression of the animal. The position of the muzzle and neck are important indicators. The head swing, as an intimidating movement without physical contact, serves to establish or reconfirm the hierarchical position in large membership groups.

BIBLIOGRAPHY:

  • The senses of the cow: Santini, Bochicchio, Volanti. With the collaboration of Feder Bio;

  • Schloeth R.1956;

  • Hall SJG 2002;

  • Mounaix B., et al. 2008.