Health, Management 

Stress in dairy cows Stress factors and their harmful effects

As with humans, when it comes to cows there are different stress factors and resulting harmful effects. Stress and stress factors play an important role in the rearing of calves and keeping of dairy cows. Farmers have many options for creating optimal conditions in the barn and thus avoid stress. As with humans, when it comes to cows there are different stress factors and resulting harmful effects.
In this article, you will find out more about different triggers of stress and which factors can lead to stress in dairy cows.

Why do cows feel stressed?

How susceptible an animal is to a stress-triggering factor, also called a stressor, has a significant effect on the condition and well-being of the animal. The sensitivity of an animal is mainly genetically predisposed. Experiences in the past, the resulting sensitivity to a certain situation as well as the condition of the animal on a particular day influence the perception of a stressor. Learned reaction patterns also play a major role. The aspects mentioned might also influence each other. Experience plays a central part here as it allows the animal to adapt more quickly to new situations and thereby better adapt its behavior.

Types of stress suffered by dairy cows

Potential stressors that can have a lasting effect on performance and animal health vary widely and change with the age of the animals (calves, heifers, cows).

Possible factors are:
  • Birth (difficult births etc.)

  • Social behavior (herd hierarchy, group changes, animal-human relationship)

  • Feeding

  • Husbandry (freestall barn, tethered housing, group housing, grazing)

  • Isolation from the herd; no visual contact (e.g. calving areas are often secluded)

  • Environment (heat, cold)

  • Transportation and regrouping

  • Change in milking staff and other contact people

  • Endogenous factors (milk yield, illness, impairments)

  • Oxidative stress (formation of reactive oxygen products that are harmful to the organism and cause cell damage) [1] [2] [3]

For example, stress caused by milking may be related to the type of milking parlor. Herringbone and side-by-side milking parlors cause considerable stress for cows. On the one hand, there is little distance between the cows, which means that there is too little individual space and there are no alternative areas to move to. On the other hand, the visual control of the cow over milking is clearly limited as it is milked from the side and from behind. [4] After the first calving, milking for the first time is also stressful because it is a completely unknown situation for the animals. For older cows or cows with a greater number of lactations, this is somewhat less stressful.

The social behavior and the associated stress are by no means to be underestimated. For example, the regrouping of cows (especially heifers) is a serious stressor. Such a group change can lead to rank fights, which may result in insufficient feed intake, disturbed water intake or reduced resting time.[1]

Stress is not only a huge burden for cows but also for calves. Therefore, stressors should be kept to a minimum during births. One of the most common stressors during births are unnecessary or unsuitable forms of birth assistance. Both the cow and the calf may be harmed by improper assistance (e.g. strains). Even after being born, there are other stress-inducing situations for calves – starting with the transport into an igloo.[1]

The serious effects of stress on the well-being, health and performance of dairy cows will be discussed in more detail in the next article. You will also see how smaXtec can help you to recognize and minimize stress earliest possible.