A mid-Devon vet, Dick Sibley, met a group of milk producers at Poyerston farm, Milton, near Tenby, recently to discuss fertility issues relating to the dairy cow.

All farmers and herdsmen present had signed up to the Milk Development Council's interactive pd+ programme, which is designed to help improve cows' fertility. Mr Sibley concentrated on heat detection and getting the animals back in calf.

This is particularly useful in herds where block calving is practiced because vets and farm management advisers now consider that, over the year, £4 per cow per day is lost for every day over a planned calving interval.

Drawing on many years of practical experience Dick Sibley - an MDC consultant - said this programme should begin when the animal is dried off before calving, ensuring that the right levels of nutrition are maintained and that appropriate steps are taken to ensure that foot problems are avoided and that udders remain healthy.

After calving the aim should be to ensure that these animals are served again after 45 days and that each holds to the first service. In practice this can never be achieved since a large number may show no signs of bulling and maybe half of those that do will return to a further service.

This is where vigilance is vital for all signs of heat detection and three-week cycling, serving within 12 hours of first sightings.

He also considered that with natural service each bull should not be expected to get more than 50 cows pregnant.

At Poyerston - farmed by Philip and Sheila Lewis and their son, Roger - their closed herd of 200 pedigree Holstein Friesian milkers calve over a four-month period, from mid-August each year.

Their cows, which produce a rolling average in excess of 9,000 kgs, average 3.5 lactations.

The herd is increasing in number by 10% each year and a cull rate of just 17% is maintained but, on a minus point the calving interval is reduced to 398 days by carrying over some of the high yielders among the late calvers to the following August.

In conclusion Mr Sibley urged that attention be concentrated on down calving heifers for at least the first 100 days: the results would mean that farmers would certainly get fitter, healthier cows that eventually lasted much longer in their herds.

He claimed that of the two million cows culled in the UK each year 29% of these was due to lameness, mastitis or infertility 'causes that might very well be avoided' he suggested.

To sign up to MDC's pd+ programme call 01285 646 500.