SPIN DOCTORS – Julia Hodkin, Future Sport Horses

If like me you find the process of selecting stallions for your mares something akin to being a kid in a candy store, then hopefully this article will help you to select the sweetest options.

Marketing of stallions has become something of a small industry in itself these days. The flashy, dramatic DVDs with the very best movie clips of a gleaming stallion produced to within an inch of its life, and accompanying high gloss brochures are enough to set the taste buds going and seduce all but the toughest of breeders. The stirring music, the carefully chosen slow motion clips and the professional presentation are all designed to excite us and make us think emotionally rather than logically. It’s a great marketing approach, but as emotion and good decision making are generally accepted as being fairly mutually exclusive, at some point if we want to make the best choices, we need to separate the spin from the substance. 

So how do we do this? Well in a lot of instances it’s not that easy due to a woeful lack of information, especially relating to event horses. How do we know what aspects of a stallion we should consider as of significance when selecting a mate for our mares? Well there are numerous aspects that will influence our decisions, and how you prioritise these aspects depends on the goals of your breeding programme. You’ve ideally got a long list of stallions which have caught your eye either through their own performance or that of their offspring, so how do we whittle that down?

The biggest point to make when selecting a stallion though is this – when you pay your stud fee you are not buying the stallion, you are buying the characteristics he passes on. That can’t be emphasized enough as it’s absolutely crucial to the process we then apply to selecting them.  If you fall in love with a black, 16.2hh stallion and dream of a little black mini-me cantering round your fields, you may well be disappointed when you get a chestnut foal that’s unlikely to make 16hh. It happens. What a stallion is himself and what he passes may be two different things. In scientific terms it’s the difference between a stallion’s phenotype (the external expression of the genes he has – i.e. what he looks like), and his genotype (the actual genes he has and can pass on to his offspring via his DNA).

For me the single most important measure of a stallion are his offspring. A stallion may have all the attributes I’m looking for in my youngsters, but unless he consistently passes them on (and the key here is the word ‘consistently’), he’s potentially a poor option as a stallion choice. It is the simple principle of reducing the risk in your programme in order to increase predictability and success. If a stallion’s offspring are not predictable you are basing your selection of him on his phenotype (his looks and characteristics) and not his genotype (the looks and characteristics contained in his DNA which will be passed to your foal), and this is a choice grounded in emotion, not logic.

So how do we keep the left side of our brain (the logical bit) directing our choices rather than our more emotional right side? Firstly we need to eject the DVD and pause the YouTube videos! The next step is to research as much information as we can from a stallion’s studbook, from performance statistics and rankings, from reference books and from the internet in general. 

One of the biggest failings in sport horse breeding data relates to the details of a stallion’s covering book. By this I mean it can be incredibly difficult to find out exactly how many mares were covered by a stallion each year. Covering information is a vital piece of the overall picture as it gives us 2 key statistics – the number of foals expected each season, and the % fertility of the stallion (I will discuss this aspect in a moment).

One of the oldest measures of a stallion comes as you might expect, from the world of racing. The ultimate measure of a stallion’s worth as a sire of racehorses, is a statistic called “winners to runners”. This statistic looks at how many of a stallions offspring raced, and from them, how many actually won. Given that the covering returns, foal returns and fertility statistics are also available for thoroughbreds we have a full picture of a stallion’s potency –

  • We know his fertility (a very important consideration), 
  • the number of foals he produced each year, 
  • how many of them actually made it into racing, 
  • and from those in racing how many were successful performers. 

In a nutshell the higher the number of winners to runners, the more reliable a stallion is at passing the attributes required for the offspring to be top performers. By looking at how many he sired, and how many actually made it into racing, we also get an indication of his potency, as a lower percentage might indicate a lack of aptitude to perform either physically or mentally. 

For sport horses, gaining this type of information can be extremely difficult. That said, it doesn’t mean we shouldn’t try! The more factual information we can gather, the more informed decisions we can make – so go ahead and ask Studs and Studbooks for this kind of information.

Given that the data for sport horses is so incomplete we need to be very careful we don’t draw conclusions from a very imperfect set of data. Missing information may lead to the data being skewed and therefore not reflecting reality as accurately as we would wish. Additionally we need to view Stallion Rankings with a pinch of salt because the WBFSH, FEI, BE and other organisations rank based on TOTAL number of points not AVERAGE number of points for progeny and therefore it is a numbers game.  Ranking on total points disproportionately favours a) the stallions who covered large numbers of mares each year (often continental stallions), and b) older stallions who have more years worth of progeny out competing.  So if you’re going to use this data, then ensure you check the age of the stallion and how many progeny have counted towards their ranking in order to create a relative ‘winners to runners’ filter.  I undertake 2 different assessments on the stallion ranking data – firstly I remove the top scoring horse for each stallion and recalculate the rankings… this removes any effects of an unrepresentative ‘freak’ performer who may even have inherited those attributes from their dam rather than their sire, and secondly I calculate the average points for progeny by each stallion. This provides 2 additional lenses on the data and enables a more rounded view to be taken, and I also look at that in relation to their age.

Hopefully you can now see the need to use the data we have to point us in the right direction, but not necessarily view it as gospel. As the old saying goes “…there’s lies, damn lies and statistics” so make sure if you’re using statistical information you know exactly the slice of data it refers to so can take into account not only what it includes, but also what it excludes, and how it may favour certain stallions disproportionately.

Having number crunched to the best of your ability given the data available, another very key consideration is compatibility. Your mares will all have certain strengths which is why you love them, but we mustn’t be blind to the areas that could be improved. The stallions you are considering should ideally improve your mare’s weaker points whilst building on her strengths. In this part of your assessment the aspects that require significant thought are – how well do their conformations work together, how might their temperaments combine, and how will the movement, jump and general athleticism mix? If we have shortlisted our stallions on their ability to produce performers, we need to whittle the list down further by removing stallions whose size, conformation, athleticism or temperament do not compliment the mare. 

Compatibility is a crucial aspect as even a top performing sire when put on the wrong type of mare could result in a youngster whose performance level is below what was expected based on the genetics. 

You may wonder why I’ve not mentioned pedigree yet? Again a stallion’s pedigree can be a fabulous pointer to the likelihood of him siring performance horses, but it’s not a guarantee. In all disciplines there are sought after lines, however coming back to my original point, if a stallion with a fabulous pedigree is not passing the characteristics that made that line fabulous on to his offspring, he may as well not have that pedigree as its attributes are not being transferred on to the next generation… 

I would whole heartedly recommend you assess the stallions pedigree in depth, particularly his motherline, and also research what ‘nicks’ or crosses have worked well with this stallion’s pedigree. Again because of a lack of easily accessible information it’s hard to find this out, but what I’ve done is look through hundreds of top performing Eventers to try to identify any recurring sires and dam-sires. It’s slow, painful and far from ideal, but it can also be incredibly enlightening.

Coming back to a point I mentioned right at the beginning of this article, we have to be realistic about the chances of getting our dream foal. If we have the ideal stallion in mind, but his fertility is poor we have to make some tough decisions about how much money we are prepared to waste trying to get a foal. Having your mare scanned empty time after time is very disheartening, and doesn’t go down terribly well with the bank manager either. If you can afford the luxury of wasted shipping and veterinary fees then go for it, but if you can’t you may need to look for a stallion with a well established track record of fertility. This is particularly important if you have a sub-fertile mare i.e. an older one, or one who has fluid problems, or if you’re considering embryo transfer.

On the same theme, the type of semen available from potential stallions is also key. Fresh or chilled may be preferred to frozen, but that said I’d rather have frozen from a stallion with known good fertility than fresh or chilled from a stallion with poorer fertility. Take advice from a good repro vet on this one though once they’ve examined your mare. 

One other minor point, but one worthy of a quick mention is this – beware the one horse anecdotal evidence. i.e. someone tells you they bred their mare to a certain stallion and the foal was really tricky, because you’ll often find that if you ask what the temperament of the dam was like you’ll hear “oh she was a nightmare”(!). Stallions get the credit (or otherwise) for offspring when really it’s a minimum of 50% the mare and if you take into account mitochondrial DNA contribution and copied behaviours – it’s even more. Other people’s experiences can be useful additional information, but make sure you get the full story and put it in context with everything else you’ve researched.

So you’ve looked at what the stallion has achieved himself, what his offspring are doing with hopefully some facts to indicate his potency, you’ve considered his compatibility with your mare, checked his fertility and semen availability, and ideally you’ve actually visited the stud where he stands and viewed not only him but his stock. Don’t forget to ask what type of mares the stock are out of as this will fundamentally affect what they look like and how they move etc.  Don’t be afraid to ask what type of mares he suits best. Some stallions can slightly be ‘one trick ponies’ in that they sire decent stock in one discipline but they wouldn’t have the attributes to cross over into another. Other stallions have the looks and athleticism to produce performers in your primary discipline, but they may also have the ability to cross over into showing or some other discipline. Versatility can be very useful if they don’t take to your intended sport or if you decide to sell the offspring as it gives you a wider pool of potential buyers.

In summary, don’t be seduced by the spin surrounding a stallion and a select few of his very well promoted offspring. To keep things in context, in Europe a stallion can easily be covering a book of 150+ mares a year, so having half a dozen out there performing is actually a pretty unimpressive statistic. Some of these stallions cover more mares in one season than a UK, USA or Australian based stallion may cover in a lifetime. 

So congratulations you’ve disciplined yourself to do all the left brain stuff. Now you can indulge the right side by switching the DVD player back on, clicking play on the YouTube videos, and falling in love with your chosen stallion all over again! Happy breeding!

Julia Hodkin, Future Sport Horses

Home of the stallions Future Illusion and Future Gravitas


07951 519288 / 07775 633004

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