Saracen Horse Feeds home page Go to the menu
T: +44(0)1622 718487



£21.50 £21.50
Per pouch

suitable for:

  • Any horse or pony to help maintain normal digestive efficiency
  • Performance horses who are training, travelling & competing
  • Those horses and ponies requiring hindgut support to maintain a normal environment

features and benefits

  • Helps to maintain optimum microbial health, activity and function
  • Supports optimum fibre and feed digestion and efficiency of utilization
  • Aids and supports the maintenance of a normal hindgut environment and stable pH
  • Contains the highest CFU count per registered feed rate

Saracen PRO-YEAST is a research-proven, live yeast additive that provides a probiotic effect. This supplement will help to optimize fibre digestion, nutrient, and energy utilisation. It is suitable for all types of horses and ponies and is particularly useful for performance horses to help maintain optimal microbial health whilst supporting and maintaining a normal hindgut environment and stable hindgut pH.

Hindgut Health

Maintaining hindgut health is vital as horses rely on energy production through the fermentation of fibre in
the hindgut. To maximise energy extraction from fibre a symbiotic relationship with the hindgut
microorganisms needs to be achieved.

These microorganisms require an anaerobic (without oxygen) environment with a pH of 6.5‐7 to thrive
and when the environment is not at these ideal conditions, this can have a detrimental effect on health
and performance.

Risk factors include:

  • High starch diets
  • Changes to feed and forage
  • Rich grazing
  • Stressful events
  • Lack of forage/fibre

All of these things can lead to the pH of the hindgut being lowered and the proliferation of lactic acid-producing
microorganisms in favour of fibre digesting microbes which leads to a change in the
microorganism populations in the hindgut. This change exacerbates the reduction of hindgut pH as higher
levels of lactic acid are produced and this then becomes a cycle, making it difficult for the horse to rectify
hindgut health.

So, what does this mean?

At a pH of 5 or lower hindgut acidosis can occur, and you may see symptoms such as:

  • Poor appetite
  • Colic
  • Stereotypic behaviours such as cribbing

However, you may also see no symptoms even if your horse is experiencing hindgut issues.

Supporting your horse's hindgut health is easy through the provision of a high fibre diet, however modern
management and feed practices combined with competition schedules and travelling can make it hard to rely solely on fibre to fuel your horse. Considering the use of a digestive aid can be beneficial in the management of optimal hindgut health but knowing which one to choose can be tricky. Saracen PRO-YEAST is a research-proven supplement that contains VistaCell, a live yeast that can help to promote a more stable hindgut environment and help to improve fibre digestion.

How does PRO-YEAST work?

Saracen PRO‐YEAST works by competing with the lactic acid-producing microorganisms that thrive in a low pH environment, to reduce the additive acid load whilst also removing oxygen from the hindgut. This process makes the hindgut environment more desirable to fibre digesting bacteria which then encourages the proliferation and activity of these microorganisms, which is what we want.

The proliferation of fibre‐digesting bacteria leads to an increase in energy supply via volatile fatty acid production which will have a direct effect on health and performance.


  • Calcium Carbonate
  • 4b1710 Saccharomyces cerevisiae MUCL 39885 (Vistacell)


Ingredient Quantity
Fibre 0.6%
Protein 7.0%
Oil 0.4%
Ash 81.2%
Calcium 32%
Phosphorus 0.16%
Sodium 0.63%
Moisture 2.6%

In line with our ongoing sustainability promise, the PRO-YEAST pouch is 100% recyclable. In order to reduce the waste of single-use plastic, we have not included a measure scoop but are instead recommending customers re-use an old scoop or use a teaspoon. A 10g daily dose is equivalent to 2 teaspoons.

The feeding rate for horses and ponies is 10g a day and a pouch will last 100 days.

Feed Frequency
Horses 10g daily (2 teaspoons)
Ponies 10g daily (2 teaspoons)
Please note a single use plastic scoop is not included within this product. 10g is equal to 2 x teaspoons

Feed Digestibility Study

PRO‐YEAST is a research-proven live yeast additive with a probiotic effect that helps promote a more
stable hindgut environment and improves fibre digestion. Each daily 10g dose of PRO‐YEAST delivers 2g
of the Vistacell Yeast.

Effect of Vistacell Live Yeast on feed digestibility

The feed digestibility study compared the use of Vistacell against a control diet. The horses were fed a
70% hay and 30% concentrate diet, with the only difference between the two treatment diets being the
inclusion of 2g/head/day of Vistacell in the treatment group. Faecal samples were collected three times
daily and analysed for a variety of digestibility parameters, with the results shown in Table 1.

Table 1: Improvement in equine feed digestibility with Vistacell live yeast supplementation.


DM, OM, NDF and ADF digestibility were significantly improved (P<0.05). Crude protein and crude fat digestibility also tended to be increased.


Daily supplementation with Vistacell significantly improves feed digestibility. The trial results show that the Vistacell group had significantly better digestibility values across all the parameters that were measured. These improvements suggest that the hindgut is healthier and more stable when Vistacell is included, leading to improvements in the populations of fibre digesting bacteria in the hindgut.

PRO‐YEAST with the inclusion of the Vistacell works by both competing with lactic acid‐producing
microorganisms to reduce the additive acid load, and also removing oxygen from the hindgut. This
makes the hindgut environment more suitable for fibre‐digesting bacteria, which then encourages
their proliferation and activity.

For more information on PRO‐YEAST please contact our nutritional team on 01622 718487 or email

Other specialist products

Find a stockist nearby

Enter your postcode to find your nearest stockist to enquire about this product.

Contact us

For Information on how to purchase this product, please get in touch with a member of our team.

Purchase Saracen Horse Feeds

Stay up-to-date

Keep up-to-date with all of our news & offers. Sign up to our newsletter here