UK DAIRY farms need to regularly weigh their growing calves to improve their life chances, according to AHDB Dairy technical manager Andy Dodd.

Calf survival is still a big challenge with 14 per cent of tagged heifers failing to reach their first calving.

“That’s something we need to change,” said Mr Dodd. “We know that good regular weight gain should ensure heifers reach their calving weight by 24 months, which in turn is incredibly good for their health, as well as the farm’s bottom line.

“However, the average calving age is closer to 28 months and we still see many heifers not calving until they are far older which decreases milk yield and lifespan, and increases the likelihood of calving assistance. Things are getting better, but slowly; we need to speed things up.”

Royal Veterinary College research, funded in conjunction with AHDB Dairy, shows that reducing calving age from 26 to 24 months saves 16 per cent in rearing costs, while heifers that don’t calve until 32 months cost an extra 41 per cent.

For Mr Dodd the answer is clear; regular weighing to ensure young stock are gaining at the right rate for their farm and breed.

“Different farms and breeds will grow at different rates,” he said. “The key is to weigh calves at birth, and then establish what their growth rate needs to be to achieve a 90 per cent mature weight at 24 months.

“The main thing with weighing is that it is regular, and that electronic scales are used. It is really hard to judge an animal’s weight simply by looking, we often ask farmers to do this at our meetings and seven different farmers will give seven different answers.”

AHDB Dairy advises that calves should be weighed as often as possible, but usually when they are being handled for another purpose to minimise stress.

As well as at birth, calves should be weighed at three weeks old (gaining 0.5 kg a day), when they are weaned (with birth weight doubled by 56 days), one week post-weaning (to check growth is being maintained), six months (27 per cent mature weight), 12 months (50 per cent mature weight), 14-15 months (breeding – 60 per cent mature weight), 18 months, and of course at calving (90 per cent mature weight).

The ideal kit for weighing is an electric weigh crush or bars, but a weigh band can be used if they are not available.

Mr Dodd said: “Weighing is the best way to diagnose a problem in a rearing system. If heifers are struggling and not calving at 24 months, weighing can be used to locate the issue.

“A group can be weighed when something changes in the system (e.g. diet/going out to grass) and then weighed again seven to ten days later which allows farmers to adapt and reduce the effect of weight gain stalling or even weight loss.”