Cow physiology leads to variation in milk yield

More than we realised, the milk yield of cows is influenced by internal, annual biological rhythms. This is according to a new study by Penn State in the US. The researchers found that the amount and composition of milk produced by dairy cows appears to be more regulated by internal, annual biological rhythms than by environmental factors such as heat and humidity. The researchers studied the production records from herds across the country for more than a decade. Photo: Herbert Wi