Cutting back protein feeding post-weaning in an attempt to save money is a false economy and could be compromising growth rates achieved in the milk feeding period.

According to Dr Scott Abbott, a Washington State vet and dairy veterinary manager for World Wide Sires, post-weaning concentrate should continue to reflect the high protein content of milk in order to maintain growth for dairy calves expected to calve down at two years old.

“I view concentrate like milk replacer because in nature calves drink milk up to 6-7 months old,” he told delegates at a joint Three Countries Feeds and World Wide Sires event, at New Grove Farm, Wedmore, Somerset, recently.

Ideally, calf milk replacer should be around 26% crude protein to reflect whole milk. Calves should be fed a 20-24% crude protein starter concentrate, which should continue to be fed post weaning. This will ensure they’re receiving sufficient nutrients for growth.

However Dr Abbott said many farmers were not providing older calves with sufficient protein. “They usually feed 16% crude protein as soon as calves are weaned to save money. And they also limit feed it and make it up with hay or straw, which is of low nutritional value,” he argued.

“This means that calves are not receiving enough nutrients and are also being fed forages that they are unable to digest due to the fact their rumens are not fully developed. Calves don’t fully develop all four stomachs and teeth until they are 5-7 months old, so they are unable to chew the cud properly.

“This can lead to ‘big bellied’ calves up to the point their rumens are fully developed at about five months old. In the meantime, it’s possible two months of growth could have been lost,” he added.

“As the animal has essentially been starved of nutrients in this time, she is also more likely to go into a state of ‘feast or famine’ where her body thinks she will be starved at certain times. As a result, she is more likely to put on back fat when she eventually starts milking.”

Dr Abbott advised not pushing too much forage into calves between 2-5 months old. He also suggested:

Feed a 20-24% crude protein concentrate up to four months old (total dietary protein of 18-20%).

Gradually introduce a TMR and move them on to a full TMR from five months old.

Avoid feeding green, fermented forages (like grass silage) in the TMR up until six months old and instead opt for hay or lucerne silage.

Move on to more forage from 4-6 months old (total dietary protein of 16-18%).