Most farmers are aware of the impact of nutrient deficiency on cow fertility, but its effect on calving ease is less commonly understood. When severe nutrient deficiencies arise the consequences can be catastrophic.

According to George Dart, partner at the Vale Veterinary Practice, Cullompton, Devon, the most common deficiencies to look out for are selenium, iodine, cobalt and manganese – particularly in grazed stock. Farmers are therefore advised to get their grass and silage fully analysed for mineral and trace element content, and make sure to add in the data for purchased feeds to accurately plan any required mineral supplementation.

Iodine deficiency can increase stillbirth rates by 15-20 per cent, as it is needed for rapid lung expansion and function in the calf after birth. Mr Dart says: “Calves are either born not breathing or breathing very ineffectively. The birth is often prolonged as well, as the calf activity is poor.”