“In the past, calving had been lasting too long because of stragglers but this is no longer the case,’’ says John Vevers who runs the herd with his son, Lindsey, near Waterbeck in south-west Scotland.

The Vevers family started using the boluses after an iodine deficiency led to an abnormal number of stillbirths in their herd of 145 suckler cows.

After seeing such good results in their cattle, they started using the boluses on their flock of 850 sheep. One of the biggest improvements has been thriftiness in the lambs.

It is now twelve months since they first used the boluses and there have been no abortions linked to an iodine deficiency. Their cows are coming to the bull much quicker too.

The ewes are bolused in January, midway through pregnancy. “The lambs get up to suckle much faster.

When there are sets of twins the firstborn is up on its feet before we have delivered the second,’’ says Lindsey. “It is so good to see. Lambing has been so much more enjoyable this year.’’