‘Mammary memory’ claim debunked

“This statement is based on the premise that the cow’s mammary cells have a memory for low production and short lactation lengths. There is no truth behind this statement,” says Kay.

“Don’t worry about when the mammary cells go on holiday as most of them won’t be coming back.”

Kay says the cells in the mammary gland (or udder) are continuously changing. 

“During the lactation, old, inactive cells die and new cells are formed. These two processes -- cell death and cell formation -- are constantly occurring and the rate at which they occur depends on factors such as stage of lactation and milking frequency. 

“The balance between cell death and cell formation determines the number of cells in the udder and this affects milk production.”

After a pregnant dairy cow is dried off, the udder resets itself during the dry period. Old inactive cells continue to die and new cells form.