What do we want the ration to do?
This is the first stage in planning youngstock rations. To answer the question, we need to know what the plan is for the animals. If they are heifers that we are planning to retain to join the cow herd we need to feed a very different ration to an intensive bull that is going finish between 12 and 16 months.
With breeding heifers, we must grow her to 65% of her mature weight before bulling at 15 months. If she has been weaned from a 700kg cow at seven months old and 275kg, then she needs to grow to 450kg over the following seven months, to reach optimum bulling weight. This is a gain of 0.83kg per day.
To achieve this, she does not need a great deal of concentrate feed if silage is of a decent quality. This is also an advantage when it comes to the lifetime lactation as over feeding starch to young heifers deposits fat in the udder, reducing lactation potential.
However, at the other end of the spectrum is her bull brother that needs to be finished within 16 months. He needs a much more powerful diet to achieve his potential and finish without going over age.
Here we need a ration that will both grow their frame and finish them. In Scotland, the primary base of these rations is barley as it is high in both energy and starch with a moderate protein level. Around 7% of the diet will need to be long fibre to stimulate cud chewing to maximise ration performance.
In between these is the yearling store. Yearling stores need to perform well enough to maximise value in the marketplace, without being overfed. Stores that are overfed when younger do not go on to perform well for the finisher.
The other issue here is when these animals go back to grass after laying down some fat cover over winter. The muscle that the cattle then grow is laid down on top of the fat from winter, meaning the fat turns to hard fat or gristle, ruining the eating quality.
To prevent this happening, keeping growing diets below 20% starch (15% if native genetics) reduces the risk of laying down fat while still maximising weight gain for the market.
Biffen’s bulls and steers
Andrew Biffen at Arnage Farms produces both steers and bulls as well as heifers. This year, Andrew has a batch of 20 bulls which are on a diet to ad-lib silage as well as an ad-lib barley with protein pellets mix. The barley is home grown and the protein pellet is costing around £340/t. Towards spring the amount of silage will reduce in the diet which will increase the amount of concentrate consumed.
“We will be marketing the bulls from June until August next year,” said Andrew. “This year we averaged around £1,500/head for the bulls. This may sound a lot but you need that price when you consider how much feed they consume. I would say at least 1.5t of concentrate maybe 2t.
“Our grades were U3 and R4L with nothing worse. Selling them was a bit tricky at the start of summer due to COVID-19 affecting the market but once demand picked up later on it was easy to get rid of them.”
The steers and heifers are on a similar diet to the bulls but they do not get ad-lib access to the concentrates which is put on top of the silage in the trough. The steers will be marketed once they are valued over £1,000 which should be at 420kg to 450kg.
Typically the Biffens start selling their stores from February onwards.
Barley will be limited in the diets of the retained heifers. Too much can put fat covers down in the udder which reduce milk yield over the lifetime of a cow.
Bull v steer
Andrew keeps all the offspring from the Stabiliser bull entire alongside some of the Simmental and Limousin calves. The rest are cut and sold as stores. He has not noticed much difference in performance between the Stabiliser and continental bulls. But he feels this may change as more Stabiliser genetics come into the herd through keeping heifers for breeding.