Should I Give My Sheep Probiotics?

By Dr Duncan Houston

Probiotics are often suggested for sheep with loose droppings, poor growth or digestive upset. They are also promoted as a way to keep a healthy flock performing well.

Some products may be useful, but the decision should start with the sheep’s diet, age and health. A growing lamb, a heavily pregnant ewe and a pet wether have different needs.

Quick answer

Healthy sheep do not automatically need daily probiotics. Selected formulations may support digestion or production under particular feeding conditions, but the evidence is mixed and benefits are product-specific. Sheep with diarrhoea, loss of appetite, weight loss or bloating need assessment of the underlying cause, especially young lambs and pregnant ewes.

What are probiotics for sheep?

Probiotics are live microorganisms that provide a health benefit when given in adequate amounts. In livestock nutrition, they are often described as direct-fed microbials, or DFMs.

They may contain selected bacteria or live yeasts such as Saccharomyces cerevisiae.

Live yeast, yeast culture and yeast fermentation products are not identical. Some yeast-based products contain few or no living organisms, so check what the formulation contains before comparing its claims with research.

How could they help the rumen?

Adult sheep depend on microbes in the rumen to ferment feed and release usable nutrients.

Certain probiotics may influence that microbial community, support fibre digestion or help maintain suitable fermentation conditions. Effects depend on the organisms, amount given, diet and animal.

A change in rumen bacteria or a laboratory marker does not automatically mean fewer illnesses or better growth. Look for evidence of the outcome you actually want to improve.

What does the research show?

Results vary.

An earlier meta-analysis of active dry yeast supplementation in sheep did not find an overall improvement in growth or feed conversion.

More recent controlled research in growing lambs has reported improved growth and feed-use efficiency with particular live yeast products. Those findings apply to the tested animals, formulations and feeding conditions.

The practical conclusion is to assess each product on its own evidence. A positive lamb feeding trial does not establish that every adult sheep needs the same supplement.

When might supplementation be worth discussing?

Your veterinarian or sheep nutritionist may consider a specific product within a feeding programme for growing lambs or another group with a defined nutritional goal.

Agree on what you want to improve and how you will measure it. Weaning, transport or medication use are reasons to review management and health, but do not automatically mean a probiotic is needed.

Start with the diet

Good-quality forage, clean drinking water and an appropriate mineral supply are the foundations of sheep nutrition. Requirements increase during growth, late pregnancy and lactation.

A supplement cannot correct inadequate energy or protein intake. Excessive grain also creates risks, particularly when introduced abruptly.

Review forage quality and the complete ration with your adviser. Ewes carrying twins or triplets may need different feeding from those carrying a single lamb. A pet sheep at maintenance has different requirements again.

How worried should you be?

What you notice	What to do
Normal appetite, activity, droppings and body condition	Discuss optional supplementation at a routine nutrition review.
Repeated soft droppings, poor growth or gradual weight loss	Arrange veterinary and dietary assessment.
Reduced appetite or unusual quietness	Contact your vet the same day, with greater urgency for lambs and heavily pregnant ewes.
Rapid abdominal swelling, breathing difficulty, collapse or severe diarrhoea with weakness	Seek emergency veterinary care immediately.

What could be causing the problem?

Diarrhoea and poor growth can result from several different conditions:

• Intestinal worms: A common consideration in grazing sheep.

• Coccidiosis: Particularly important in growing lambs.

• Infections: Including salmonellosis and causes of newborn lamb scours.

• Dietary upset or grain overload: Especially after sudden feeding changes or accidental access to concentrates.

Your vet will consider age, recent feed changes, body condition and how many sheep are affected. A faecal examination may be useful, but treatment should fit the findings and the whole clinical picture.

A pregnant ewe that stops eating needs particular attention. Pregnancy toxaemia can begin with reduced appetite and depression, then progress to weakness and neurological signs. It is more common in ewes carrying multiple lambs and is not a condition to manage with probiotics alone.

When is this an emergency?

Call your veterinarian immediately if a sheep has:

• A rapidly enlarging abdomen, particularly on the left side.

• Laboured or open-mouth breathing.

• Collapse, staggering, seizures or inability to stand.

• Severe watery or bloody diarrhoea with marked weakness.

• Known or suspected access to a large quantity of grain.

Bloat and severe grain overload can deteriorate rapidly. Do not wait for a supplement to work, and avoid forcing liquids or paste into an animal that cannot swallow normally.

Should lambs with scours receive probiotics?

A veterinarian may include a suitable product as additional support, but correcting dehydration and maintaining nutrition are the priorities.

Contact your vet promptly about a scouring young lamb, particularly if it becomes quiet or less interested in feeding. Do not assume every case is caused by worms.

Milk generally should not be withheld simply because a lamb has diarrhoea. Oral electrolytes can provide additional fluid and salts under a treatment plan, but they do not replace the nutrition in milk.

A lamb that cannot stand, suck or swallow normally needs urgent assessment and may require intravenous fluids. Probiotics also cannot replace timely, adequate colostrum intake after birth.

Check that the supplement is suitable for sheep

This matters especially when a digestive supplement also contains minerals.

Sheep are particularly susceptible to copper toxicity. A product intended for goats, cattle or another species may contain unsuitable amounts of copper for sheep.

Use a formulation labelled for sheep or specifically approved for your animals by your veterinarian or nutritionist. Check the complete ingredient list, including added minerals, and consider everything else they are receiving.

How should you choose and use a probiotic?

1. Investigate symptoms first. Do not let supplementation postpone examining an animal that is unwell.

2. Check the exact formulation. Look for identified strains, the live organism count where applicable, and evidence relevant to sheep.

3. Follow product-specific directions. Confirm the feeding rate, age suitability, expiry date and storage conditions.

4. Plan reliable delivery. Make sure the intended amount can reach the animals through your feeding system.

5. Set a review point. Record the outcome you want to improve and reassess whether continued use is worthwhile.

There is no universal probiotic dose for sheep. Different products cannot be compared simply by scoop size.

What should you monitor?

For an individual sheep, record appetite, droppings, activity and body condition. Body condition scoring by hand helps reveal changes hidden by wool.

For a flock trial, useful measures may include lamb growth, feed consumption, treatment rates and cost per animal. Compare similar groups where practical and account for changes in pasture, ration and weather.

Improvement after starting a supplement does not prove the supplement caused it, particularly if several aspects of care changed together.

Common mistakes to avoid

• Assuming all probiotic strains and yeast products are interchangeable.

• Using products with unsuitable mineral content.

• Treating persistent scours without investigating the cause.

• Changing several supplements and feeds at once.

• Waiting while a lamb or pregnant ewe stops eating.

How can you support digestion day to day?

Make feeding changes gradually, keep feed and water clean, secure concentrate stores and maintain a suitable ration for each group.

Work with your vet on parasite monitoring, coccidiosis control and appropriate vaccination. Clean lambing areas, good colostrum management and consistent bottle-feeding practices are particularly important for young lambs.

Can probiotics replace worming or coccidiosis treatment?

No. They should not replace treatment prescribed for a diagnosed parasite problem. Your vet can help select treatment and assess whether it has worked.

Should sheep receive probiotics every day?

Only when there is a reason to use a particular product that way. Healthy sheep do not need indefinite supplementation as a default routine.

Can I use the same probiotic for goats and sheep?

Some products are suitable for both, but check the label and all added ingredients. Do not assume that a goat supplement, particularly one containing minerals, is appropriate for sheep.

ASK A VET™ supports practical flock care built around good nutrition and early recognition of illness. Your veterinarian can help you decide whether a probiotic has a useful role and what to monitor next.