White spots in breeding-back cattle

Along with the Hornless allele, the alleles for white spots are among the gene variants definitely not wanted in “breeding-back” as white spots are a trademark sign for domestic animals of any species. However, the genes are in the pool for breeding-back. With this post, I want to have a look at how common they are and where they come from. 

The genetic background for white spots is complicated in cattle. It is important to note that the so-called colour-sided variant present for example in Texas Longhorn is caused by another locus named Colour sided and is different from the piebald pattern we see f.e. Fleckvieh or Frisian and breeding back cattle. The white streak on the face or forehead is caused by the KIT locus. A Spotted allele was coined which is claimed to be responsible for the piebald pattern, but the inheritance for white spots does not suggest a mere Mendelian trait. First of all, white spots seem to cumulate – many individuals might have just a few tiny white spots on the ventral side of their body, but when bred to another individual with white spots they get larger and more widespread, until the individuals are completely piebald. Furthermore, the inheritance of the spots is complicated and might also be influenced by sex (see the next section). 

Heck cattle (and Taurus cattle)

The number of Heck cattle individuals showing white spots on the belly or a streak along the face/forehead is not inconsiderable. You find a number of individuals with these traits on google. In Oostvaardersplassen, where no phenotypic selection occurs, such individuals are particularly widespread. There was at least one completely piebald individual reported (van Vuure 2005). I saw a piebald individual myself in the Lainzer Tiergarten herd in Vienna. Heck cattle has many colour alleles from its ancestral breeds, and white spots are among them. They were probably inherited from the one Black-pied bull Heinz Heck used (perhaps also Corsican cattle which carry the genes on occasion). 

Taurus cattle also may have white spots seldomly, for example the otherwise very good cows 42 508 and Lisette. Margret Bunzel-Drüke reports that the inheritance of white spots in the Lippeaue is curious – female offspring of cows with spots often have them too, while males tend not to. So the particular genes they have might be sex-dependent. White spots are comparably rare in the Lippeaue population, only a handful of individuals have or had them. In the Lippeaue, these might be inherited from all four ancestral breeds: Heck cattle, Lidia and Sayaguesa all may have the genes, and even Chianina where it would be masked due to the dilution alleles that make their coat completely white. 

Taurus cattle in Hortobagy, Hungary, also might have spots on occasion. This is because red-pied and black-pied bulls were used right before they were able to acquire Heck and Taurus bulls, and there is still a good-looking half-Holstein cow in the herd. The otherwise rather good-looking breeding bull Zseuz was selected out because it has white spots on the belly that transferred to its offspring. 

Tauros cattle 

Of the founding breeds of Tauros cattle, at least Sayaguesa have the genes for white spots, and at least one cow that I know of has one on its belly. A number of the Sayaguesa x Tudanca individuals has spots on the belly (go here). 

Auerrind

I have not seen any individuals with white spots in the Auerrind project so far, and it might be that there are none. However, the herd the Sayaguesa are from is the same as those of the Taurus and Tauros cattle project (Peter van Geneijgen), so it might be possible that the genes are in the Auerrind mix, but only future can tell. 

What does this mean for breeding-back? Actually only that white spots are simply widespread among domestic cattle in general. They are present in all groups and types of cattle and so also in breeding-back cattle. It is, however, the question whether individuals with spots should always be selected out or not. Surely no project wants that their cattle would end up piebald in the wilderness, such as the Heck cattle in Oostvaardersplassen. This is a complicated question as the genetic background of those spots seems tricky and unresolved and it is probably up to the individual breeder. However, if someone does not want white spots in any individual, they of course can select out each individual showing them.