Trial work reveals optimum crude protein intake for beef bulls A student from Harper Adams University College has won the Wynnstay Beef Award for his involvement in a trial that has shown that many beef producers are feeding too much protein to beef bulls.

The EBLEX funded trial studied the effect of feeding barley based rations, containing varying proportions of dietary crude protein, on the performance of forty eight 280kg Holstein bulls.

Agricultural student, Peter Briggs, carried out the research under the guidance of senior lecturer, Simon Marsh, while studying in the final year of his degree at Harper Adams University College in Newport, Shropshire.

“We commissioned the trial because many consultants are advocating a rearing diet for cereal fed bulls of 16% crude protein for animals up to 250kg liveweight and 14% from 250kg to slaughter,” said Mr Marsh. “The results of the study show that increasing the protein content above 12% for 280kg bulls does not improve physical or financial performance. Many bull beef producers are therefore over-feeding protein”

Table 1: Beef bull performance

The beef bulls were split into three groups, with each group receiving a diet of either 12%, 14% or 16% crude protein. Each group achieved recognised targets for cereal based beef production, recording daily liveweight gains of between 1.32 and 1.34 kg and achieving slaughter weights of 542 to 557kg at around 13.5 months old.

“There was no significant difference between the three groups in terms of liveweight gains,” Mr Marsh explains. “However, the bulls reared on the 12% diet did record the highest margin over feed costs and the highest gross margin per bull.

“Farmers using home mixed rations can therefore improve gross margins by as much as 10% per bull simply by reducing the amount of protein they are feeding,” Mr Marsh adds. “In terms of financial savings, that is equivalent to around £7.60 per bull at current prices. Since the trial was completed finished beef prices have risen and feed prices fallen. There is now money to be made by intensively finishing black and white bulls, provided they are reared to a high standard of management.”

Table 2: Gross margins based on purchasing store bulls at £0.65/kg  

 Steve Brown, ruminant technical manager for Wynnstay Feeds, who presented the award to Peter at the College’s graduation ceremony, commented that “compound feeds that are backed by really meaningful research are woefully lacking in the UK.

“Many intensive beef producers who are reliant on concentrates to provide the necessary dietary requirements therefore have to just make do with what is available and are losing money as a result of over-feeding,” he adds.

“Evaluating the effectiveness of different feed rations makes it possible to deliver a bespoke diet that offers the optimum level of protein. This level of detail and understanding is invaluable to farmers and as such we felt that Peter’s work made him a worthy winner of the Wynnstay Beef Award.

“In fact Peter’s research has prompted us to reformulate our PrimeBeef range of compound feeds to ensure that our customers are receiving a product that has the most cost effective balance of nutrients,” Mr Brown concludes.

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