SPARKS

ON THE CUTTING EDGE OF RARE BREED MANAGEMENT

The Cleveland Bay Horse Society has embraced a software program called SPARKS (Single Population Analysis & Record Keeping System), which has been adapted after many months of effort to aid in the ongoing preservation of the purebred Cleveland Bay.

The Cleveland Bay Horse is critically endangered, as listed on the Rare Breeds Survival Trust, with slightly less than 125 purebreds in North America.

This software was developed by the American Zoological Society and the International Species Information System to guide captive breeding programs for the world's rarest and most endangered species.

The entire CBHS Studbook has been entered into the SPARKS software by CBHS Council member Andy Dell, and with assistance from the staff at ISIS it is now up and ready for the use of the CBHS to help breeders of purebred Cleveland Bays evaluate potential matings.

What SPARKS, and its sister program GENES, has enabled is a detailed genetic and demographic analysis of the living population of Cleveland bays and it provides guidance for managing genetic health in the future.

The measure it uses is MEAN KINSHIP (MK). This is the numerical value of how closely an individual horse is related to every other in the world population of Cleveland Bays. This gives us an indication of just how rare an individual's combination of genes is in the entire population. Animals with a lower Mean Kinship have relatively fewer genes in common with the rest of the population, and are therefore more genetically valuable in a breeding program. An individual animal's MK number is a moving benchmark, which changes as the world population changes with births and deaths, and so every living Cleveland Bay's MK number is recalculated every year and new data is issued.

Using this information it is possible through a coordinated strategy to breed to minimize Mean Kinship and maximize the retention of genetic diversity.

To simplify the strategy the population is divided into alphanumeric bands, based on Mean Kinship. To cover the range of MK numbers in the CB population seven bands A, B, C, D, E, F, and G have been used. The majority of Cleveland Bay stallions and mares fall into bands C< D and E.

So, what do we do with this information, and of what importance is it?

The ideal genetic matings will occur when the resulting progeny has a lower MK number than both the sire and dam, and when the sire and dam are from the same alphanumeric band. SPARKS does not recommend skipping more than one band.

The aim is to reduce Mean Kinship but also to avoid bringing rare bloodlines together. Crossing animals of similar mean Kinship prevents undesirable matings between animals from different rare lines.

So, for example, CB stallion Big Brownie has a MK of 0.205, and is from Band C. CB mare Big Ears has a MK of 0.209, and is also from Band C. SPARKS tells us that their progeny would have a MK value of 0.195, so this is a good match genetically. SPARKS does not factor in conformation, type, and other normal breeding considerations, so we must still make sure we look at the horses!

First, we can as individual breeders choose to incorporate SPARKS as another tool when making breeding decisions with our purebreds. Our genetic diversity cannot sustain being compromised much more, and it is the goal of CBHS and CBHSNA to reduce the average MK number of the population by half.

Please feel free to contact the Secretary of the CBHSNA for more information.(info@clevelandbay.org)