Back to articles

store lambs

Digestible fibre key to smooth store lamb transition

For store lambs, the transition from autumn grazing to indoor finishing is critical if digestive disorders and growth checks are to be minimised. Both are major causes of reduced margins, with acidosis also the main reason for the high rates of store lamb mortality often seen during the first few weeks of housing.

But according to Trident technical manager Dr Michael Marsden, the solution is relatively straightforward. What’s needed is a change in focus from diets based predominantly on starch energy to those based on digestible fibre energy.

“The underlying cause of acidosis in store lambs is an excess of starch and a lack of fibre in the ration, particularly digestible fibre,” he explains. “With a large proportion of indoor store finishing rations based mainly on cereals, what’s needed is a much better balance, particularly during the early phases.

“Too often, store lambs are brought in off pasture and have been fed no concentrates outdoors – or very little – to start the adaptation process. Throw in the fact that many are also straight off the hills, through the markets, then immediately housed on full finishing rations, and the stresses of the transition are obvious.”

The high price of cereals this year is an additional incentive to feed more cost-effective feeds high in digestible fibre energy, such as sugar beet feed, distillers’ feeds and soya hulls. In fact, Dr Marsden suggests that even those farms that traditionally feed home-grown wheat or barley may generate more profit this winter by selling the cereals and buying in alternative feeds.

“Even when the price of cereals is low, relying too heavily on them to make up the majority of the ration is generally a false economy,” he continues. “By all means use stocks of home-grown cereals as part of the ration, but make sure the starch is buffered adequately in the rumen by also feeding sources of digestible fibre. The alternative is slower growth, poorer finishing and less profit.”

Managing the transition onto indoor feeding should also be started as soon as possible. Research has shown that store lambs offered sugar beet feed at a rate of just 0.2-0.5kg/lamb/day in the field before being brought indoors will adapt to the finishing ration much more quickly, with the 12mm sugar beet nuts suitable for feeding on the ground while at grass.

For finishers buying store lambs at market, this isn’t an option, making the initial ration fed absolutely critical to successful adaptation to indoor finishing. Dr Marsden’s recommendation is to start with a ration containing at least 25% of the ration freshweight (FW) made up from feeds high in digestible fibre energy, lowering this gradually to a minimum of 10% over the first six weeks if more starchy feeds need to be fed, or economics favour such a move.

However, Dr Marsden claims that in most cases there’s little need to feed additional starch, or economic benefit. Research at ADAS Rosemaund showed that lambs fed ad libitum diets containing up to 20% sugar beet feed (FW basis) had leaner and heavier carcasses than those fed a proprietary compound.

Table 1 compares three example finishing rations, safely incorporating differing levels of cereals

by including both digestible fibre (sugar beet feed) and extra protein (soyabean meal, bio-ethanol wheat distillers’ feed). All the examples should be offered ad lib.

Table 2 – Example rations for intensively finished lambs at different

% inclusion

(freshweight basis)

Diet A

Diet B

Diet C

Barley

40.5

32.5

27.5

Sugar beet feed

15

35

30

Bio-ethanol wheat distillers’ feed

12

5

Maize gluten

10

Soya hulls

15

10

10

Rapemeal

15

15

15

Hi-pro soyabean meal

5

Vitamin & mineral supplement

2.5

2.5

2.5

Energy (MJ ME/kg DM)

12.2

12.1

12.1

Protein % (as fed)

15.8

15.1

15.3

Starch & sugars % (as fed)

25.0

22.0

21.2

Cost (£/t FW)*

£204

£211

£206

* Blend prices quoted correct at time of going to press, based on 10t blown loads delivered 21-40 miles from source, prices will vary with load sizes and distance from source.

“Growth rates for small breed Highland lambs finished indoors, for example, have been shown to improve from 185g/day to 200g/day when switching to rations based on digestible fibre, rather than cereal-based compounds,” states Dr Marsden. “And that’s on top of the benefits of reducing acidosis risk and minimising any growth check during the transition indoors.

“Just make sure the ration contains around 15-16% crude protein as the minimum, especially for improved breeds, using supplements high in rumen-bypass protein like rumen-protected soyabean meal (SoyPass) to provide the extra quality protein needed for high growth rates.”

Find where to buy

Click on the map to go through to find your local merchant.

Find your local merchant