Video: Feed efficiency up to 41p/kg gained in Angus herd

Young bulls in the Rawburn Aberdeen Angus herd require 0.2kg less feed on average to grow 1kg of liveweight in their first winter than in 2020.

The Elliots of Roxburgh Mains, Kelso, say this is thanks to just one generation of breeding decisions informed by feed efficiency (FE) data captured by electronic feed bunks. 

Most efficient bulls hit a feed conversion of close to 3:1 – this is 3kg of dry matter (DM) intake for every 1kg of liveweight gained.

See also: Stabilisers feed efficiency value could save £100 an animal

The latest November trial found the best bull needed 1.13kg less feed than the average (see table).

This is a saving of about 41p for every kilo gained on the farm’s ration by the most efficient weaned bull in its first winter.

“It’s easy to improve something when you start recording it for the first time,” says John Elliot, who hopes the long-term benefit will be cows that take less land to feed and have lower maintenance costs.

“In my opinion, nothing in beef farming can offer as big an injection into profit and feed cost reduction as feed efficiency to suckler and beef farming. The heritability is good, and we’ve seen a benefit in one generation.”

Breeding for feed efficiency

FE has been added to the selection process, rather than replacing anything, explains Mr Elliot.

But by favouring bulls that have ticked all the historical criteria of breeding, type, structure and estimated breeding values (EBVs), as well as having good FE, average feed to gain has fallen from 4.38kg to 4.18kg in the three years of trials at the farm.

This saves 7.4p/kg gained, which over the 50 days and 116kg gained, is worth £8.58 a head.

Rawburn Loaded is one such bull. He scores well for ease of calving and short gestation, and has strong growth figures, but also had sons with better-than-average feed efficiency, says Mr Elliot.

Not every bull will perform well, and as feed efficiency data grows and daughters of high-FE bulls are retained, it should be possible to target a low-FE bull that is exceptional for other traits at a high FE cow family.

“It may be that we get the best of each side,” says Mr Elliot. “You cannot see feed efficiency. There could be otherwise identical bulls stood next to each other, but one needs 30% more feed to gain the same as the other.”

Big investment

The Elliots considered investing in FE for several years and seized their chance when the price of the electronic feed bunk system lowered from nearly £200,000 to £130,000 in 2020.

The data are used alongside EBVs and pedigrees to market bulls for commercial suckler farmers. The herd sells a select few sires to pedigree breeders and a dozen or so bulls head to dairy farms each year.

“We hope we can add value to our bull sales and also cut costs at home by breeding a more efficient herd,” explains Mr Elliot.

“As pedigree breeders, we must give our customers value. They need to get the benefit of our breeding programme, the heterosis and the genetic gain.”

How it works 

Eight Growsafe feed bunks are in the Roxburgh Mains cattle shed, with 20-25 bulls sharing four bunks each side of the central passage.

Bulls are fitted with HDX tags and are weighed and recorded every time they drink, which can typically be five or six times a day in winter. Start and end weights are averaged to account for gut fill.

The feed is weighed before and after each bull visits the feeder and each visit is logged.

Bulls are fed an oat-based ration with distillers’ dark grains, sugar beet pulp, soya and rolled barley. The bunks are filled every morning and Himalayan rock salt is provided ad-lib.

Data are transferred from a box on each set of bunks to a computer in the farm office.

US tech company Vytelle analyses them. Animal Nutrition company Norvite supplies information on the grower ration independently.

So far, there have been six trials, with two cohorts of 40-50 bulls measured each winter for a 50-day period. Oldest bulls have been fed from November and the younger bulls from January.

Data is checked and anomalous numbers assessed each day in the US. An animal must have 30 days of feeding data to be included.

The cattle must:

• Be within 200kg liveweight and 90 days of age of each other at the start of the trial
• Spend 10 days on the feed in trial conditions to allow their rumens to adjust
• Have 90% of the feed allocated to them each day by the computer – any less and the day is void (most days its 98% or more)
• Be bedded on wood shavings so they cannot eat the bedding.

Pre-trial

Cows are outwintered until March on stubble and hay and straw on bale trailers. About one-third of the cows are on stubble turnips this winter.

Calving takes place indoors over 12 weeks until late May. Calves are creep-fed from late August until weaning in early November to ease weaning, which is done outside between a fence in batches of 40 cows and calves.

Bulls are fed ad-lib big bale silage and an oat-based ration.

When they move onto the feed efficiency trial the silage is replaced by a high-fibre pellet because the silage cannot be weighed and fed accurately.

Post-trial

Ad-lib silage is brought back into the pen after the trial and the bulls continue to eat the oat-based ration alongside the silage.

Bulls are turned out in early spring when conditions allow to harden up and grow off grass alone. “This is a really important stage,” explains Mr Elliot. “We want to know they are ready to work.”