12 June 1998

High yields for top merit cows

HIGH genetic merit cows are on target to average 5500 litres from forage in their current lactation in one ADAS Bridgets study.

Thats according to farm manager Robert Bull, speaking at a Royal Association of British Dairy Farmers open day at the Martyr Worthy research centre in Hants.

The MDC-funded project aims to prove that high production from forage can be sustainable and profitable and devise management strategies for high genetic merit cows on high forage diets with maximum use of grazed grass.

This will include identifying ways to maintain cow condition and achieve good fertility results on a high forage diet, said Mr Bull.

Physical and financial performance of the high forage group will be compared with that of other study groups at ADAS Bridgets, including the high yielding Elite herd.

The 30 mid- to late-lactation cows in the study average £55 PIN, and are yielding 25 to 27kg from grass alone. Grass is rotationally grazed with a fresh area offered every 24 hours.

"They have received no supplementary feeds for six weeks, and are on target to average over 5500 litres from forage with a predicted lactation yield of more than 8000 litres," said Mr Bull.

The group, which block calved in late November and early December, show a conception rate to first service of 62%, while the average days to conception was 89 and 90% of cows are now in calf.

A supplementary study in February and March using similar cows compared three systems winter feeding, with winter feeding at night and rotational grazing by day, and zero grazing grass.

"Cows out by day did not seem to suffer a production loss compared with those on a full winter diet, but cows which grazed were cheaper to feed" he said. &#42