Synergy 15KG (Formerly Base Mix)

(5 customer reviews)


SKU: SYNERGY15 Category:

****Please note: Synergy was formerly called Base Mix. There was no change to the formulation when the name was changed****


A concentrated, cereal free, balanced feed suitable for horses of all disciplines, veterans and youngstock.

With generous amounts of added prebiotics, probiotics, fruits, herbs and botanicals, providing functional foods to nutritionally support a healthy gut environment.


Why choose ‘Synergy’?


  • No fillers, binders, pelleting agents, preservatives or chemically synthesised micro-nutrients are included.
  • Contains essential amino acids, fatty acids, nucleic acids, natural vitamins, chelated minerals and over 100 anti-oxidants to nutritionally support a healthy equine.
  • All ingredients have been carefully sourced, wherever possible, to avoid chemical treatments such as pesticide and herbicide, preservatives and mould inhibitors, etc.
  • Contains no wheatfeed, oatfeed, soya, sugar beet, molasses, alfalfa, soya oil, corn oil, mixed vegetable oil or waste by-products from human oat or wheat food milling and production.
  • All Ingredients have been carefully processed to minimise denaturation of the essential macro and micro nutrients.

****Please note: Synergy was formerly called Base Mix. There was no change to the formulation when the name was changed****


Stabilised and ground whole linseed, naturally stabilised rice bran, natural fractionated yeast extract, proprietary blend of herbs (fruits, herbs and botanicals), limestone flour, magnesium carbonate, Bioplex minerals, Lysine, Yea-Sacc, Bio-Mos, Natural vitamin E, chelated magnesium, chelated calcium, chelated zinc, chelated copper, chelated selenium, organic extra virgin sesame seed oil, natural vitamin A and D3.


Oil (21.3%), Protein (22%), Starch (7.5%), Sugar (2.2%), Fibre (18.6%), Ash (11%) DE=14.2MJ/kg


Key nutrients provided for a 500kg horse when fed at 500g per day
Natural Vitamin A 15,000iu; natural Vitamin D 3,000iu; natural Vitamin E 500iu; Folic Acid 25mg; Nicotinic Acid 65mg; Pantothenic Acid 35mg; Riboflavin 52mg; Vitamin B12 0.74mg; Thiamine 60mg; Pyridoxine 85mg; Selenium (all chelated form) 0.75mg; Iodine 5mg; Zinc (all chelated form) 400mg; Copper (all chelated form) 100mg; Lysine 12.4g; Methionine 2g; Biotin 15mg; Calcium (carbonate and chelated form) 10g; Phosphorus 6g; Magnesium (carbonate and chelated form) 7.5g, Yeasacc 5g;

Add a handful or two of Thunderbrook Healthy Herbal Chaff or Muesli to provide texture and aid chewing. Dampen before feeding. If feeding at the maximum amount, split between two feeds per day.
Feed alongside ad lib forage. Provide plenty of fresh water and access to a salt lick as Synergy does not contain added salt (average horse at maintenance requires approx. 20g per day). Always introduce a new feed slowly. Add just one pinch of Synergy to your horse’s first feed and work up gradually over four or five days to the full amount (see below). See feeding guide below for amounts.

Healthy adult horses at maintenance or in light to medium work, on poor forage, restricted grazing, track system etc, convalescing horses or those with a compromised digestive system. 100g per 100kg body weight.
Pony up to 300kg
300g per day
Horse up to 500kg
500g per day
Horse 500kg to 750kg
700g per day

Healthy adult horses at maintenance on good forage, good doers or those which do not require weight gain.
50g per 100kg body weight.

Pony up to 300kg
150g per day
Horse up to 500kg
250g per day
Horse 500kg to 750kg
350g per day
Youngstock, Broodmares, horses in medium to hard work & competition horses.
100-150g per 100kg body weight.


Pony up to 300kg
300g to 450gg per day
Horse up to 500kg
500g to 750g per day
Horse 500kg to 750kg
700g to 1050g per day


Amounts given are dry weight per day. Preferably split between two meals per day.


We process all orders received before 2pm on the same day. Orders received after 2pm will be processed on the next working day.

We send all orders on a ‘Standard Delivery’ so please allow 1 – 3 working days for your delivery to arrive.

Delivery costs are as follows

1kg – 5kg parcels – £4.99

5.1kg – 30kg – £6.99


Returns Policy

If you would like to return your purchase you may do so within fourteen days of delivery. Please ensure:

Your item is unopened and undamaged.

You remain responsible for the item until we receive it (we recommend sending your item ‘signed for’ or tracked).

You are liable for all return shipping costs unless we have sent you an incorrect or faulty item.

5 reviews for Synergy 15KG (Formerly Base Mix)

  1. SueAjax-Lewis

    Following severe colic when he nearly died, my 33 year old PBA, previously a really good doer, seemed unable to regain his former ‘glory’. He had lost his usual layer of subcutaneous fat and looked spare and ‘leggy ‘ no matter what or how much I gave him. He was also a bit ‘low’ in himself, looking his age.
    Winter approached and I was seriously worried.
    I came across Thunderbrook when researching nutritional feeding for horses and I am so glad I did.
    Since he has been on Thunderbrook products – and that’s all he has now- he has put back on the much needed weight (particularly important over the winter) and has got back his joie de vivre and personality which seemed to go awol after the colic.
    I believe Base Mix (along with the Herbal Muesli, Ulsa-x and Meadow Nuts) has given him back a life worth living. He is enjoying himself again.
    It provides all the nutrients, vitamins, minerals etc. required by a horse on a daily basis, so important for their well being. Read the contents; the time and effort to research and create this balancer must have been enormous and so worth it.
    In addition, Thunderbrook minimise processing and try to avoid chemicals so all their feeds are as pure as possible.
    I like to think of it as ‘clean eating for horses’.
    As soon as he sees me in the yard, he stands at the gate and shouts to come in for his dinner and I have to hold up the bowl when he gets near the bottom so he can lick it clean.
    (Spoilt? Never!)
    For his age, he’s as good as he possibly can be.
    I’ve got my old horse back. Thank you Thunderbrook..

  2. Ava Treutler

    I have had my horses on Thunderbrook feeds for the past month and what a change I’ve seen. They are both gaining muscle, dappling out, have better attitudes, and they really enjoy their feeds. The Basemix has turned my two hard-keeper thoroughbreds into good-doers on 500g of it per day. Thank you for amazing products. Couldn’t recommend them enough.

  3. Vicky Harrison

    I’ve had my girl on Ulsa x, healthy muesli, and base mix now for a month, and she absolutely loves it. She’s a very good doer, I contacted Thunderbrook, for feed advice after she tied up last winter, so I was unsure of what to feed her, as she does lack energy when riding on long hacks, as our grass is quite poor and haylage is not the best quality. I was advised the three foods stated above, and now she’s a very happy horse, and has got her mojo back! Would never go back to ‘off the shelf’ feeds again.

  4. Charlotte Hornsby

    I’ve had my 3 show jumpers on this for over a year now and they look great. Their coats have a lovely shine which people always comment on. One of the horses had very poor hooves which would crumble and be difficult to keep shoes on but since he’s been feed this the difference and strength of his hooves is amazing. The 3 of them can be very sharp and certain feeds I have used in the past have definitely made them worse however I’ve not found this to be the case with hay cobs and base mix.

  5. Madeleine Weightman

    I have moved all my horses onto the herbal chaff and base mix and all have never looked better. I have youngstock, broodmare and competition horses on it. I was initially worried about energy levels for the competition horses, but they have the right amount of energy without being fizzy. Their coats have never looked better and my broodmare came out of winter well and cycling early so we’re also easy to put in foal.

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