Get the best from grass and forage for store lambs

Those wanting to manage store lambs as cost effectively as possible should minimise concentrate use and get the most from grass and forage crops, according to ADAS sheep consultant Kate Philips.

“In the current market there just isn’t the margin to go down the ad-lib concentrate route,” she says.

“With compound feed prices at about £200/t, and a feed conversion efficiency of 7:1 it will cost £1.40 to gain a kilogram. With a current lamb price of £1.52/t, it doesn’t make a lot of sense.”

It’s important to do the sums and make sure you are getting a premium for using concentrates, agrees EBLEX beef and sheep scientist Liz Genever.

“Generally it is difficult to justify significant concentrate supplementation now.”

As a result, producers on an ad-lib concentrate system may need to look at storing lambs for longer, with forage crops offering the cheapest option.

But, because some brassica crops were planted after a late harvest, it may be worth holding off using them until Christmas and taking advantage of strong autumn grass growth, says independent beef and sheep consultant David Hendy.

However, although those in the south may be able to get away with using grass for longer, producers in the north shouldn’t wait too long, says Dr Genever.

“Northern areas may get frost damage earlier, so their priority should be getting the best use of forage crops.”

And those using grazed grass should make sure swards are managed effectively to ensure good performance next season, she says.

“My main concern with the recent flush of grass is that sward heights will get too high and dry matters may be low – strip grazing is a good way of getting the most from grass and ensuring it is eaten down to the required 4-5cm before being shut up for winter.”

And in wet weather, supplementing a high DM feed, such as barley or oats, may be necessary to account for low DM grass, Ms Philips says.

Leaving catch crops that bit longer could also help if recent wet weather is a sign of things to come, allowing good ground cover to be established and reducing chances of poaching.

Including a grass “lay back” on brassica ground could also help reduce damage and give lambs the opportunity to get off the crop when conditions are poor, says Mr Hendy.

“But choosing an efficient management system for stores will depend on what type of animal the lamb is,” he continues.

“A lamb weighing less than 30kg could be grazed on grass first, then brassicas and only fed concentrate at the end of the finishing period to get them up to 3L.”

But, when lambs are bought weighing more than 35kg, they could be supplemented with concentrates at grass to get them finished quickly.

“Stores should be achieving a liveweight gain of 120-150g a day on short term keep and 80-90g a day on long-term keep – but it is essential sufficient drinking water is provided to achieve these gains.”

Trace element status must also be monitored, with particular attention paid to cobalt levels, Ms Philips says.

“A lot of store lambs stop growing because of lack of cobalt which is important for energy metabolism.

“Blood testing a sample of lambs is a good way of assessing status and making sure stock are not being held back.” Boluses, free access minerals or drenches can then be used when a deficiency is identified.