Weaning Lambs - Roughage for young lambs

The preparation of lambs for weaning is a vital process to reduce the risk of a growth check during the transition from milk and to ensure lambs continue to thrive. It is therefore important to ensure lambs have access to clean and fresh water; high quality concentrates and a sufficient source of roughage alongside their milk supply. The type of roughage supplied can influence many factors, such as rumen development.

For lambs reared on an ad-lib feeder rather than the ewe, Volac does not recommend providing free access to hay. If you are feeding lambs a good quality hay, there is the risk they will eat large quantities of the hay, in turn reducing the intake of starter feed.

The hay has a low energy density, and the effect of increasing intake can give lambs a classic pot bellies appearance, similar to that seen in calves. The hay gives considerable rumen ‘fill’ however it does not support the development of good functional rumen, this is encouraged more by the consumption of good quality concentrate feeds.

Offering clean straw (which is less palatable) in racks, the need for long fibre can be fulfilled without a substantially detrimental effect on solid feed intake. Boosting solid feed intake at an earlier stage encourages earlier rumen development and reduces the risk of a significant growth check at weaning, this can also offer the chance to wean earlier than would be the case for lambs reared on the ewe.

In order for this to be achieved, the lamb must be consuming at least 250g/day of solid feed. Higher early growth rates can be achieved by the practice of offering high quality concentrates and straw in racks, compared to that of feeding ad-lib hay and concentrates.

Straw is also a good abrasive fibre source, helping to improve papillae integrity.

1. Rumen papillae and epithelial development – which improve rumen ‘functionality’. Achieved through the consumption of good quality lamb creep feed (fermentation of concentrate/carbohydrates)
2. Increase in rumen volume – (by forage intake). NB: the increase in volume is not directly linked to ‘functionality’ of the rumen.
3. Papillae integrity - by diet abrasiveness/coarseness. The ingestion of coarse particles of feed (including straw) together with more finely ground concentrate feeds, helps to prevent papillae clumping and excessive keratin (a wax secreted by rumen epithelium) accumulation on surface of rumen papillae – this, in turn, increases absorptive function.

Lambs which remain with the ewe are not typically weaned abruptly from the dam and often stay on the ewe for up to 8 or 9 weeks. This means that they are usually older at weaning than lambs reared off the ewe and the functionality of the rumen would naturally have developed more in these older animals. This means that there is less pressure to develop a functional rumen in a shorter time frame, and therefore less of a need to limit access to hay.

From a practical viewpoint, it is also a challenge to restrict the lambs access to a quality roughage source as this should always be available to the ewes.

In all cases, once lambs are weaned give them access to good quality hay, straw or grass – with any large changes to the diet being managed carefully to avoid sudden changes to intake patterns.