Finishing lambs on cereal-based rations.

Summer has been kind to livestock farmers, particularly in Scotland where average grass growth has exceeded the four-year average since early July (GrassCheck GB, 2023) giving late-born lambs a brilliant start.

Approaching the winter months, and with grass quality starting to drop, more creep feeders appear on farms to get finished lambs away before the New Year.

Feed cereal prices have dropped significantly since this time last year making finishing lambs with a cereal-based home mix a cost-effective option for anyone with a plentiful supply.

However, cereal finishing is not without its risks. A high cereal diet, if not managed correctly, can lead to issues such as acidosis and an increased risk of urinary calculi if minerals are not properly balanced.

Top 10 steps to ensure safe feeding of cereal-based rations:

1. Do not over-process grain. Lambs can efficiently utilise whole grain but if processed, only a light roll or crack is necessary. Over-processed grain will be rapidly fermented in the rumen dropping pH and increasing the risk of acidosis.

2. Ensure functional fibre. All ruminants require a source of functional fibre for rumen function – this may be grass, silage, hay or straw. If concerned, a fibre source such as beet pulp, soya hulls or a higher fibre cereal such as oats, should be included in the home mix (usually around 10% inclusion).

3. Balance protein. In order to effectively utilise energy, it is important there is sufficient rumen digestible protein in the ration. Ensuring the home mix is between 14-16% crude protein (as fed) will help ensure there is sufficient protein available for ration utilisation. If feeding barley and dark grains, this is a grain-to-protein ratio of 4:1.

4. Introduce slowly. It takes between 2-3 weeks for the rumen to adapt to a new diet. Introduce the cereal slowly, first by providing small feeds twice a day and gradually increasing the feed until there is some left in the trough at which point hoppers can then be introduced. Lambs should never be introduced to a hopper from empty. If this is not possible, ensure there is no more than 50% cereal in the mix.

5. Never let the hopper empty. The hopper must be kept with feed at all times. Letting the hopper become empty will result in lambs gorging, leading to acidosis.

6. Consider treatment. Moist barley can be prop corned for lambs which will help rolling quality and reduce the risk of spoilage. A urea and enzyme-based treatment can also be a good option for the treatment of moist barley reducing the requirement for additional protein and increasing the pH of the feed for better rumen balance.

7. Mineralise the mix appropriately. Cereal-based rations also pose a high risk of urinary calculi in intact and castrated males. Using an intensive lamb mineral with 0.5% or 5000 mg/kg ammonium chloride will help to mitigate this risk. Keeping the calcium-phosphorus ratio of 2:1 will also help to mitigate risk.

8. Include a rumen buffer such as sodium bicarb (2% inclusion) or a commercial buffer that can help increase the pH of the ration and reduce acidosis risk if feeding untreated grain.

9. Always ensure a clean fresh water supply.

10. If housed, think about the space available. Lambs need space to lie and ruminate. Space allowance for housed lambs on ad-lib cereals and straw or hay is as follows: up to 3 months – 0.5M² per lamb, 3-12 months – 0.75-0.9m² per lamb.