Feeding Youngstock For Safe Growth And Development

Whether you have bought a youngster to produce yourself or you’re breeding from your mare, it’s imperative that you get their nutrition right from the beginning. With nutrition being essential for development and growth, choosing the right horse feed is vital. So, what should you be feeding youngstock for safe growth and development? 

Alfalfa As A Source Of Protein

Alfalfa is very beneficial for breeding and youngstock. It’s renowned for supplying quality protein which is required to support optimal growth. The quality of a protein is determined by the levels of essential amino acids as they can’t be synthesised in the horse’s body. A particularly important essential amino acid for youngstock is lysine. If this amino acid is deficient it can compromise growth and development. 

The myth stating that excess protein causes Developmental Orthopaedic Disease (DOD) has been dismissed and it is now known that high starch diets, especially if mineral levels are reduced, are more likely to be a problem. 


Alfalfa is known for being abundant in calcium. Primarily found in bones, calcium is also important for muscle contraction, blood coagulation, enzyme regulation and cell membrane function. Too little calcium for the mare during pregnancy or the foal can result in skeletal deformities. The ratio of calcium to other minerals, such as phosphorus, is also important. Too much phosphorus can block the absorption of calcium resulting in a calcium deficiency. This is most frequently a problem when straight cereals are fed without additional sources of calcium.  

What Are Growth Disorders?

Developmental Orthopaedic Disease (DOD) is the umbrella term used to describe any growth-related problem. These can be very obvious and easily recognisable such as contracted tendons where the foal appears to be walking on tiptoes, or they can be much more subtle and difficult to definitively diagnose such as Wobbler Syndrome. 

Why Do Growth Problems Occur?

DOD is a multi-factorial problem and some of the factors are easier to influence than others. One of the most difficult to control is that of genetics and so it is important to consider that sometimes problems will occur regardless of how much effort you put in to try and avoid them. A contributing factor that can be influenced is nutrition.

How Does Diet Influence Growth Problems?

The growth of the foal begins at the point of conception and the diet needs to take account of this. The foetus accumulates mineral stores that it can draw on during the first few months after birth when it is growing very rapidly. If DOD occurs during this time it is often an indication that the foetus wasn’t able to accrue sufficient stores. This can be due to a number of reasons, the most usual one being that the mare didn’t receive additional minerals in the diet and so couldn’t pass them to the foal. Sometimes the health of the placenta is compromised by infections or old age and this can impair the transfer of nutrients to the foetus. This doesn’t mean that you shouldn’t breed from older mares, you just have to accept that there is an increased risk of problems. 

The aim with a youngster is to achieve as smooth a growth rate as possible. If a youngster experiences a period of sub-optimal nutrition which is sufficient to slow their rate of growth, they will catch up as soon as they receive a higher plane of nutrition. This can result in “compensatory growth” and may result in a weaker musculoskeletal structure and delay maturation. It is therefore vital to supply enough energy but not too much to ensure a consistent rate of growth. 

One myth that has well and truly been dispelled is that excessive protein causes DOD. A study carried out by Kentucky Equine Research (KER) in the USA showed that in fact, high blood glucose levels and the consequent high insulin response to a cereal based meal was associated with an increased incidence of DOD. The advice from the researchers was to reduce reliance on cereal based feeds for youngstock and use fibre and oil as energy sources instead, especially when prepping for shows or sales. Feeds such as Alfa-A Oil would be ideal as they provide as much energy as a stud mix but typically with 10 times less starch. These should be fed alongside good quality sources of vitamins and minerals to ensure the diet is balanced. 

When adding minerals to the diet the crucial factor is that they are balanced. Feeding more of one mineral in isolation is not necessarily a good thing as it upsets the balance of others. For instance, limestone is frequently added as a source of calcium as most people are aware that calcium is required for bone development. Although calcium is important, feeding too much can block the availability of other minerals such as zinc and copper, which are also vital for growth and development. Copper, for example, is an important constituent of the enzymes that are needed to give tendons their elasticity.  

How To Manage DOD

Although there are still many questions unanswered one thing that is known is that hay and water is not good enough. Just as you wouldn’t expect a child with a developmental problem to improve on bran flakes and water, foals need a balance of essential nutrients to repair the damage. A supplement or low-calorie balancer fed with a chopped fibre feed such as Alfa-A Original will provide the nutrients needed to build healthy tissues without the starch that increases the risk of problems. 

If you would like more information about what to feed youngstock for safe growth and development, don’t hesitate to get in touch with an equine nutritionist. 

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