Complex sentence: No equine coat colour genetics studies have been done specifically on Fjord horses, but if Fjord horses were not homozygous for the dun gene, then a dark-coloured, nondun individual could occasionally occur in the breed.
Split into simpler sentences: No equine coat colour genetics studies have been done specifically on Fjord horses. But, if Fjord horses were not homozygous for the dun gene, then a dark-coloured, non-dun individual could occasionally occur in the breed.