The impact of light on the eggs of laying hen has been known for a long time. The lighting environment also has an impact on the quality of the milk.
Indeed, the milk produced by cows in the evening has ten times more melatonin than the milk produced during the day. Evening milk would be a natural and effective help for the calf to fall asleep. The saying about drinking a glass of warm milk to improve sleep probably comes from the milk consumed just after milking in the evening. Therefore, evening milk is a perfect natural anxiolytic.
Some European firms already sell this particular milk as a beneficial alicament for well-being and sleep. All future opportunities can be considered to make ruminants produce therapeutic milk naturally without modifying the genome but by changing the farming environment. Here is an epigenetic example which means a change in the environment that affects gene expression and milk quality.