Irish Draught Breed Conservation

In March of 2005, the first half of a Royal Dublin Society commissioned genetic study of the Irish Draught herd was presented. I traveled to Ireland to hear this information first hand from geneticists Brian Wickham and Victor Olori.

Wickham and Olori described the Irish Draught breed status as "endangered maintained". The WWL-DAD (World Watch List for Domestic Animal Diversity) of the FAO (Food and Agriculture Organization of the United Nations) defines endangered maintained populations as groups of animals (ie breeds) experiencing a declining population trend such that survival of the breed would require a "concerted effort to arrest the negative trend in population size". Preliminary data gathered by Wickham and Olori confirm a declining trend in registration along with an increasing level of inbreeding since 1979. It is interesting to note that the overall level of inbreeding in the Irish herd has jumped significantly in the years since 1991, when performance testing of stallions was instituted as a pilot program.

We view this data as confirmation of something many have long suspected - there is decreasing diversity in the herd and it is likely that a significant factor in this trend is stallion selection. There are those who say that "rare bloodlines are rare for a reason". This is true but...many of the reasons are not what you'd expect.

RID sires may be under-utilized for a variety of reasons. Some stallions had limited progeny due to their location. Moorpark Boy lived on top of a mountain in Co. Wicklow where he was all but inaccessible to purebred mares. Most of his progeny were out of the local heavy draft forestry mares used to sling timber on the mountainside and were therefore not eligible for the RID studbook.

Some bloodlines were so widely known for their strong work ethics that all the colts were gelded to supply the demand for working geldings or hunters, leaving no intact sons to carry on a line. Two such families were the Woodranger and Sweetheart lines, which are thought to have been casualties of their own popularity. Luckily the Woodranger line has been revived, but Sweetheart exists only through dam lines.

A phenomenon called "the cult of the popular sire" has driven the selection of a few performing bloodlines with the goal of producing profitable sport horses, namely those offspring of King of Diamonds and Pride of Shaunlara. The popular stallion effect is quite evident in the RID studbook. King of Diamonds alone had 34 sons and grandsons on the stallion register when he died. As further evidence, O'Toole (2001) demonstrated that King of Diamonds accounted for over 7% of the genes of purebred Irish Draughts born between 1997 and 2000 inclusive, and that almost 50% of the genes present in that population could be attributed to just 17 ancestors, presumably the result of overuse of certain sire lines.

Finally, a huge influence on diversity has been wrought by the institution of IHB performance testing. Historically stallion owners have been farmers which means very few have had the financial resources to campaign and performance test their animals. This financial disincentive, combined with an effective bloodline bias, has reduced available sire lines even further.

So what is an Irish Draught breeder concerned with the future viability of the global herd to do?

We believe that education is the driving force. We are involved with various educational efforts with the goal of drawing attention to the issue of genetic diversity in the Irish Draught breed and highlighting the power the individual mare owner wields in making each year's breeding decisions. We hope these efforts will help spread the word and perhaps foster a change in breeding policy long term. In our own program, we choose horses from under-utilized sire lines to expand our herd with the aim of producing athletic outcrosses of excellent type. We will also occasionally utilize horses from the more common bloodlines if we feel a stallion's exceptional traditional phenotype warrants conservation. We feel we have a responsibility to be sure the sires we select for our broodmare herd are not just "names on paper", but that they are excellent examples of their sire and dam families in appearance, ability, and prepotency. Through our continued research, education, and breeding choices, we endeavor to assist in the conservation of this extraordinary rare breed in our own small way. If you'd like to learn more about conservation breeding as it applies to the Irish Draught horse, or if you'd like to join us in our efforts, we'd love to hear from you! Contact Liz.