Simultaneous Lactation and Pregnancy

Because she is re-impregnated while still lactating from the previous pregnancy, a dairy cow spends seven months of every year simultaneously pregnant and producing large quantities of milk. This enormous physical demand requires her to eat over four times more food per day than a beef cow at pasture. Her average milk yield will be between 30-50 litres a day, 10 times more than a calf would drink, so her udder is forced to work unnaturally hard. In addition, a calf would normally feed five to six times a day so that the maximum amount of milk in her udder at any one time would be around two litres. But on most dairy farms a cow is milked only twice a day, allowing milk to accumulate in the udder and can force her to carry around 20 litres of milk or more. This greatly enlarges the udder and leads to lameness in her hind legs and predisposes her to mastitis (a painful infection of the udder).

Her only rest from this demanding workload is during the last two months of her pregnancy when she is ‘dried off’ in preparation for calving – then the whole cycle starts again. This gruelling cycle takes its toll on her body.

“…a depressing number are culled after only two to three lactations because they are worn out, either through complete loss of body tissue (emaciation), or breakdown of the udder tissues, or chronic lameness.”

Professor Webster