Calcium is an important nutrient for humans. There is more calcium in the human body than any other nutrient, so the demand for calcium — often in the form of dairy milk — is high.
Dairy cows, as a result, have to produce a lot of milk to meet the demand. But 5—10 percent of North American dairy cows suffer from hypocalcaemia, a condition that results in low levels of calcium in their blood and milk. Besides lowering calcium levels, hypocalcaemia is associated with fewer pregnancies and digestive problems in dairy cows.
Laura Hernandez and her team of researchers from the University of Wisconsin-Madison conducted an experiment to give dairy cows serotonin — a chemical in the brain commonly associated with feelings of happiness — in an effort to prevent hypocalcaemia.
The results showed that serotonin increased calcium levels in the blood of one breed of dairy cow and in the milk of another breed of dairy cow. It did not, however, raise the yield of milk.
In short, happy cows make better milk. It’s got more calcium in it and could lead to further changes in the dairy industry. Hernandez said that if serotonin could raise calcium levels in milk sustainably and healthily, then “that would allow dairy farmers to maintain the profitability of their businesses, whilst making sure their cows stay healthy and produce nutritious milk.”