How feeding according to breed can benefit growth rates

Research is showing why it makes financial and practical sense in dairy-beef enterprises to match different breed growth rates to a farm’s acreage, labour availability and infrastructure.

A study on two research farms in Ireland shows that gender, liveweight and body condition score are also key when targeting finishing strategies. 

Growth weights of steers and heifers at farms under the umbrella of Irish advisory, education and research body Teagasc are being monitored and the latest set of data shows how the pattern is different according to three factors.

See also: 7 focus areas for efficient beef finishing rations

Steers and heifers born from dairy cows in 2024 using Aberdeen Angus, Hereford, Belgian Blue or Limousin sires are involved in the trial. Aberdeen Angus and Herefords are considered early-maturing breeds, while Belgian Blues and Limousins are later to mature.

There are key differences between steers and the pattern of gain in females, as shown by the measured daily liveweight gain over two summers.

Teagasc’s Dr Nicky Byrne, who is involved in the project, says this data gives finishers a range of options and also demonstrates how the seasonality peaks and troughs in beef supply from spring-born dairy-beef cattle can be reduced.

He advises that every beef farmer’s goal should be to feed as much home-grown forage as possible to hit high carcass weights at younger slaughter ages. Finishing suitable cattle before housing can reduce feed requirements and free up shed space for the winter.

“Finishing early-maturing animals at grass during their second grazing season can be a highly efficient strategy, particularly for well-developed heifers and steers by late summer,” he says.

This strategy offers several advantages, including freeing up winter housing for younger stock and reducing overall feed costs, ultimately improving overall efficiency.

Fergal Maguire © Fergal Marguire

Genetics influence outcome

Estimated strong lifetime performance and getting cattle to a sufficient liveweight at the start of the finishing period is recommended – this is achievable with a short concentrate feeding period of six to eight weeks from mid-August.

Cattle best suited to this are those born early in the spring and with a high commercial beef value index, says Nicky. This is used in Ireland, but also in the UK in some breeds such as Shorthorns; UK farmers base decisions more on estimated breeding values and specific dairy-beef selection indexes.

“Indoor finishing is particularly suitable for late-maturing breeds, as these animals have a greater capacity for lean tissue growth, which allows them to respond better to high-energy finishing diets, resulting in improve feed conversion efficiency and increased carcass weight and conformation.”

He recommends that farmers regularly draft cattle to ensure they meet market specifications to optimise returns.

Less developed early-maturing cattle – animals born later in the spring and those with limited genetic potential – are often better suited to a long period at grass and delaying finishing until they hit target weights. “These animals can then be finished indoors more efficiently,” Nicky suggests.

“Advanced late-maturing heifers, when appropriately supplemented, may be finished at grass under a similar regime to that used for early-maturing steers during their second grazing season.”

Teagasc DairyBeef 500 adviser Fergal Maguire says the decision on whether to feed concentrates should be dictated by grass supply and quality, cattle weight and target finishing date.

But even when cattle are to be finished indoors, it can be beneficial to feed concentrates at grass, he says. This will reduce the quantity of silage they will need further down the line and allows for a gradual build-up to the indoor finishing diet.

© Debbie James

Cost savings from autumn grass

Grass growth generally slows in the autumn and sward quality can deteriorate, but even when taking that into account, autumn grass is a relatively low-cost feed compared to silage and concentrates.

“Keeping suitable finishing cattle at grass can still be more economical than housing them,” says Fergal.

For steers with access to good-quality grazed grass in the autumn, he recommends offering about 0.75kg of concentrate for every 100kg of liveweight – which works out at 4.5 kg/day for a 600kg steer.

When grass supply is limited or grass quality is only moderate, he advises increasing feeding rates to about 1kg/100kg liveweight.

Feed a high-energy concentrate with at least 12.5MJ metabolisable energy/kg of dry matter and 11-12% crude protein. When the diet includes more than 4kg of concentrates, Fergal suggests splitting it between morning and evening feeds.

Ideally, cattle should be within 60-80kg of their target slaughter weight when concentrates are introduced into their diet.

Early-maturing heifers should weigh about 480kg at the beginning of September and be at the point where they are starting to lay down fat.

“When offered 3.5kg/day of concentrate, weight gains of 1kg/day can be achieved, which should allow suitable heifers to reach about 540kg liveweight and a carcass weight of about 270kg,” says Fergal.

Early-maturing steers weighing 490kg or more by 1 September are also potential candidates for finishing off grass, because when they are supplemented with about 4kg of concentrate a day an average daily liveweight gain of 1.1kg is achievable.

By early November, this can grow suitable steers to about 570kg liveweight and a 300kg carcass. Fergal warns, however, against unnecessarily pushing lighter cattle, as these might be better suited to finishing indoors later in the season.