You’ve probably heard it said that happy cows make the best milk. It’s a popular slogan, particularly among California dairy farmers, lauding the superior conditions afforded to cattle in that state. However, it’s more than just catchy marketing lingo. Science has proven what anecdotal evidence has long suggested: happy cows really do produce better quality dairy products. To understand how and why requires some understanding of the connection between happiness and hormones.
The study in question was the brainchild of Dr. Laura Hernandez, Assistant Professor of Lactation Biology from the University of Wisconsin. In order to test the theory that happiness impacted the quality of a cow’s milk, it was necessary to have an objective measure of the animal’s happiness. After all, translating their moos was out of the question, especially considering that contented cows moo much less than when they are upset. Luckily, there is a hormone that is directly related to happiness in both humans and animals. It is called serotonin.
Serotonin is a neurotransmitter that performs a number of complex functions within the brain, but for our purposes (and those of Dr. Hernandez) the most important is the hormone’s effect on mood. Elevated levels of this hormone in the blood are associated with happier moods, a healthy appetite, and decreased stress and anxiety. In order to ensure that the cows being tested were happy, they were administered serotonin daily, which produced an increase in their calcium production. While the nature of this increase varied by cow breed, in Jersey cows it translated directly into more calcium-rich milk.
In the study, the administration of serotonin did not otherwise directly impact the nutritional profile of the milk or the yield. Yet, those characteristics are impacted by a cow’s happiness. We can infer this based on what we already know concerning the impact of stress and adverse conditions on our bovine buddies.
When under stress, cows don’t produce as much milk. This occurs in part due to another hormone, adrenaline, being released as part of the animal’s fight or flight response to negative stimuli. Long term stress, likely a result of poor treatment and living conditions, is almost certainly coupled with decreased levels of serotonin, which in turn leads to a poor appetite. The less a cow eats, the less milk it can produce, and what it does make will be of lesser quality.
Another hormone, cortisol, is released in response to chronic stress. At elevated levels, cortisol compromises the cow’s immune system, making it more susceptible to infection and illness. In turn, more bacteria can enter and survive within the milk. While milk tends to be pasteurized to eliminate bacteria, raw milk has a greater nutrient density. The raw milk from a happy cow is far more likely to be safe for consumption than that of an unhappy one.
Within the farming industry, the push towards the more humane treatment of livestock has long been underway. Consumers and farmers alike have pushed for this out of a sort of moral kindness, but it helps to know that there are commercial benefits as well. Happy cows really do produce the best dairy products, which means that it’s in everyone’s best interest not to give them anything to moo about.