Gradually weaning dairy-bred calves off milk could be worth a staggering £12.04 a calf in increased liveweight compared with abruptly weaning calves.

A study by Harper Adams University college found that calves weaned off milk abruptly at six weeks of age were, on average, 8.6kg lighter at 11 weeks old than calves weaned off milk gradually from five to one litres a day in the last week of weaning, also six weeks.

A total of 36 Holstein and Continental cross Holstein bull calves all received colostrum within the first six hours of birth and for the next three days. They were individually penned and bucket-fed milk replacer twice a day and offered early weaning concentrates ad-lib to weaning.

Calves weaned abruptly were more unsettled, resulting in a marked effect on performance and daily liveweight gain post-weaning, says Harper Adams senior lecturer Simon Marsh.

“At 11 weeks old, abruptly-weaned calves weighed, on average, 96.8kg compared with 105.4kg for gradually-weaned calves. If this additional 8.6kg of liveweight gain is valued at £1.40/kg, it is worth £12.04 a calf.”

And although total feed costs to 11 weeks old were similar, because of the improved performance of the gradually-weaned calves, they recorded reduced feed costs worth a 16p/kg gain.

“Gradually-weaned calves consumed 11.5kg more feed and recorded an improved feed conversion ratio, resulting in gradually-weaned calves having a higher DLWG from weaning to 11 weeks – 1.22kg compared with 0.993kg, respectively,” says Mr Marsh.

But he adds that although, for the purpose of the trial, all calves were weaned at six weeks, in reality concentrate intake should be the main weaning criterion.

“It is vital that calves are eating at least 1kg of concentrates a day before they are weaned off milk,” he says. “It was noted during the trial that abruptly-weaned calves eating less than 1kg of concentrates a day were more vocal due to their initial hunger. And because it takes time for calves to discover that all their energy requirements must come solely from concentrates, there is a check in growth.”

Mr Marsh accepts that gradual weaning demands more labour, but the financial gain is significant. “Some producers may be under certain constraints, making gradual weaning difficult, so it is even more important that they make sure calves are eating at least 1kg a day before weaning,” he says.

Gain from gradual weaning

Liveweight

Abrupt

Gradual

Start

47.2

47.2

Weaning

62

62.7

11 weeks

96.8

105.4

DLWG (kg)

Abrupt

Gradual

Start-weaning

0.353

0.369

Weaning 11 weeks

0.993

1.220

Start 11 weeks

0.644

0.755