New photos of Alvarez the Auerrind bull

Claus Kropp recently released new photos of Alvarez, the Sayaguesa x Watussi bull of the Auerrind project, on facebook. Go here, here and here for the photos. 

© Claus Kropp

Alvarez is developing well. The horns seem to grow large - the bull is not even nearly fully grown yet. He will be moved to the three Sayaguesa x Chianina cows this year. 
That means we can expect (Sayaguesa x Watussi) x (Sayaguesa x Chianina) individuals for next year. I am extremely looking forward to this combination. It might be the most promising combination of the project as it has the potential to unite all needed traits in the right quantity. It will have many Sayaguesa genes, and with Chianina size and Watussi horn size genes this cross product would look almost ideal. That requires luck of course, it could also be that the small horns of Chianina and small body size of Watussi get passed on, most individuals might have a phenotype somewhere in between. That's why I hope that Alvarez will stay with the cows for more than one year. I think that producing at least two good individuals of this combination that can be bred to each other would be a major step forward for the project. 

Did aurochs and wisent hybridize?

Hybridization is very common in the animal kingdom and takes place everywhere closely related species meet each other. There are plenty of examples where hybridization played a role in speciation, not only in amphibians and fish but also mammals, including us humans. For a post on hybridization, go here. 

In recent years, it has been suggested that the wisent is a species hybrid of aurochs and steppe bison because the wisent clusters with domestic cattle on mitochondrial level. For details, go here. This theory has recently been questioned by a 2016 paper that suggests the affiliation of wisent and cattle mitogenomes are more likely a result of incomplete lineage sorting. It also suggests an early split from the steppe bison, from which it differs in head orientation associated with food choice. While the American bison and Steppe bison have a lower head orientation than the wisent as they are primarly grazers, the wisent has a higher head orientation and is a mixed feeder, which is probably the result of living in a more forested habitat [1]. A 2017 study indeed suggests that Bison schoetensacki was the immediate ancestor of the wisent [2].  

However, the wisent does show signs of admixture with Bos in its nuclear genome [3]. The study compared both modern and pre-bottleneck wisents to cattle and the 8.000 year old British aurochs with the fully resolved genome and found signs of interbreeding with domestic cattle. The authors also emphasize that it is possible that these genes are not from domestic cattle but from aurochs closer to domestic cattle than the British aurochs. Either domestic cattle or aurochs or both left their track in the genome of the wisent. However, the very small portion of Bos DNA suggests that this introgression did not happen in recent times. Hybridization may indeed explain the diverging horn shapes sometimes found in wisent, like in this individual at Hellabrunn Zoo I photographed in 2011: 

It is important to note though that wisent and cattle do not interbreed spontaneously. Not a single case of hybridization between both species in the wild has been reported even if they share the same habitat [4]. All wisent-cattle hybrids were created in human custody. However, it might have happened that domestic cattle genes found their way into the wisent genome over those hybrids. If they escaped and joined wild wisent herds, they might have been more likely to interbreed than pure cattle. 

Another possibility would be that both species interbred more easily than today when aurochs arrived in Europe during the middle Pleistocene and later further diverged due to the so-called Wallace effect or reinforcement. In this case, hybrids between aurochs and wisent would have a lower evolutive fitness than pure individuals, thus decreasing the likelihood that both species interbreed. This is just a thought-experiment of mine. 

Another possibility if aurochs and wisent indeed interbred in the past could be that the influence from wisents helped the newly arriving aurochs, which migrated from subtropical areas, to cope with the European climate. I would not be surprised if the curly hair on the forehead that can also extend to the entire neck, dewlap and shoulders which are found in taurine cattle and European aurochs, were in fact vestiges of hybridization with wisents, as those curly hair is very opulent in bison but completely absent in zebus and other Bos cattle. 

Because of the fact that bison and Bos cattle can interbreed, some authors tend to list them all as one genus Bosin recent years. I tend not to. There are no objective measures to determine what is one genus or more than one, it entirely subjective just as all systematic ranks. Hybrids between genera are not that uncommon, for example in chicken, whales (see “Wholphin”) and there is even one case in elephants (see “Motty”). Paleonotological evidence suggests that bison descend from Leptobos, and genetic evidence also suggests that yaks are in fact part of the bison branch and might descend from Leptobos as well. Bos, on the other hand, might descend from Pelorovis. In this case it could well be that all Leptobos and Pelorovis species could interbreed with cattle and bison if they were alive today. Thus they would have to be included into Bos as well, making it an extremely variable super-genus based solely on the fact that they can interbred. And, to be consequent, other genera would have to be lumped as well. Pseudorca and Tursiops and all related genera would have to be listed as one genus, and one might even go that far to synonymize Loxodonta with Elephas. The ability to interbreed alone might not be the best criterion for synonymizing genera, especially as it is gradual from fully infertile offspring to only one sex being fertile to fully fertile offspring. 

Literature 

[1] Massilani et al.: Past climate changes, population dynamics and the origin of Bison in Europe. 2016.

[2] Palacio et al.: Genome data on the extinct Bison schoetensacki establish it as a sister species of the extant European bison. 2017.

[3] Wecek et al.: Complex admixture preceded and followed the extinction of wisent in the wild

[4] Vera: Do European bison and domestic cattle cross spontaneously? 2002. Vakblad Natuurbeheer 

Resting aurochs bull portrait

The putative Pajuna crossbreed of the TaurOs Programme inspired me to do a portrait of a resting aurochs bull: 

The horn shape is based on a skull from Germany. Some might wonder why I tend to draw large-horned aurochs. This is simply because this horn size is very common in European aurochs bull fossils. But my next aurochs is going to be a short-horned individual like this one, I promise. 

Breeding-back: How I would do it

In this article, I want to outline how I would execute “breeding-back” myself if I had the chance to breed a herd. There are multiple ways to Rome of course, and I am not saying that I would do it better than anyone else, it is just how I would do it. 

1. The goal

My goal would not be to breed yet another “breeding-back” herd, but to produce a high-quality line that is as genetically stable as possible even if genetic diversity has to be sacrificed. Of course genetic diversity is important, but the purpose would not be to fill the entire European continent with this herd exclusively, but to produce high-quality individuals that can improve the quality of other herds and therefore the gene pool of “breeding-back” cattle as a whole. This is similar to the line bred by Walter Frisch (the Wörth line), who produced a herd of Heck cattle with the best horns found in this breed, which are also comparably stable in inheritance, what contributed a lot to the improvement of horns in other Heck cattle herds. This was also achieved by the use of inbreeding in order to stabilize traits. 

2. The starting herd 

Of all the primitive breeds and “breeding-back” herds on this world, what would I compose my starting herd of? I would take a number of good Taurus cattle from the Lippeaue because I think they represent the top quality of contemporary “breeding-back”. I would select individuals that have the right colour, are large, have a good body shape and proportions and take care that the choice of individuals also includes genes for large and correctly curved horns. Maybe one or two Auerrind crossings with Watussi genes would be included as soon as they are available. This starting herd would include all genes for the desired traits that domestic cattle have: large size, aurochs-like proportions, aurochs-like horn curvature and dimensions, wildtype colour and sexual dimorphism. 

3. The breeding 

I would use a large chef bull that would cover all the cows. In order to speed up the process, I would not use the same individuals/generations for too long but instead replace them quickly with the subsequent generation. If the first filial generation has produced a good bull and good cows that are at least as good or better than their parents, I would sell the parental generation (or at least the chef bull), the offspring taking their place. In the subsequent generation, I would do the same and so on and so on. When selecting I would try to continuously increase the level of quality. Due to the inevitable (and in this case, wanted) use of siblings mating as well as selection, the gene pool would continuously narrow. The result would be a quality line that is comparably stable for the desired traits. It has worked with the Wörth line, it should also work with Taurus cattle. 

4. The selection 

Every breeder has his own priorities concerning selection criteria. I would pay a lot of attention to body shape, proportions and size because these traits are controlled by a large quantity of genes, surely dozens and possibly hundreds, while colour is regulated only by about a dozen of genes. I would also prioritize inwards-curving horns because they are comparably difficult to breed as this trait is rare in primitive cattle. Due to the use of Chianina, alleles for colour dilution might be present quite frequently in the population. I would try to eradicate those two or maybe three alleles, even if it might take a while as they are recessive. It has worked in the Neandertal and Wörth line, it should also work here. I would select against bulls with a colour saddle, as the European aurochs probably did not have this trait and it might be a sign of reduced colour dimorphism. However, I would not always select out black cows, as historic evidence reports the existence of black aurochs cows in Europe. For the horn size, we have quite a large spectrum indicated by fossil and subfossil bones. However, I would not permit horns that are only the size of Sayaguesa horns or smaller. Horn size is most likely regulated by a large number of genes, and it might be that genes for small and thin horns are sometimes recessive. In the Wörth lineage, small-horned individuals still might appear occasionally. Recessive alleles are very difficult to breed out and also requires luck. 

Breeding works with luck and by coincidence. One would need patience, especially when using the method as described in section 3. In the Lippeaue, many individuals are half-Sayaguesa. Half-Sayaguesa will always look good in some way because Sayaguesa is a very good breed. But it becomes more difficult when you mate crossbred individuals among each other, because inheritance works by chance. The result might have the large horns of Heck cattle, or the small body size. It might have the large size of Chianina and long legs, or the diluted colour. Londo, the Taurus bull, was the result of two siblings mating. He looked a lot like his father Lamarck, but was smaller and short-legged. However, due to its genotype there was the chance that he was more stable than its father (which is not stable at all as it is a cross), and indeed he seemingly passed on the short legs with stability. This shows that using siblings mating for stabilization can work quite fast. In the case of Londo it was simply bad luck that he was stable for short legs and not for his good traits. 

New photos of three Auerrind bulls

Claus Kropp recently released new photos of three Auerrind bulls on Facebook: 

From left to right: Sayaguesa x Grey, Maremmana x Watussi, Sayaguesa x Maremmana  © Claus Kropp

Grey cattle x Sayaguesa © Claus Kropp

Maremmana x Watussi © Claus Kropp

The Sayaguesa x Maremmana bull looks good, although it is impossible to predict what cattle will end up looking like before the age of 3 years. Its horns still have the grey protective layer, what means the horns can still grow quite a bit. The Grey cattle x Sayaguesa bull looks like an aurochs-coloured version of Grey cattle, with a bit more forwards-facing horns. The Maremmana x Watussi bull reminds me a lot of Heck bulls from the Wörth lineage, especially in terms of horn shape, except for the red colour and the zebu hump of course. 
I would cross those bulls with the Sayaguesa x Chianina cows, they would add alleles for large size, long legs and forward-facing horns. Or maybe also the Chianina x Watussi cow for more horn volume. 

The largest Taurus bull

How large are Taurus cattle? Several individuals have been measured. The first Taurus bull that was measured was Lucio, the first Heck x Sayaguesa bull. He was 160-165cm tall at the withers. This was the only measurement for a Taurus individual until I visited the Lippeaue in 2015. I took a yardstick with me and we measured a couple more individuals. Two cows were measured 153-155 cm at the shoulders, both cows had average size compared to the other individuals. The cow Larissa is noticeable larger than both, so that she might be 160cm tall at the withers. The bull Linnet is about the same size as Bionade (the cow measured 155cm at the withers), so he should be about 155cm tall as well. 

As for the largest bull on the site, 42 623, we have no direct measurement but an indirect one. When standing next to the large Sayaguesa cow Dona-Urraca, he almost dwarfed her, so we already knew that he has to be very tall. We then measured the distance between a metal bar of a cage that he was able to touch with his withers and the ground, so that we could infer his size. It was 173cm, so that the bull is at least 170cm tall at the withers. It is thus the largest Taurus bull measured, and the largest “breeding-back” bull in general. 

42 623, the largest Taurus bull (Sayaguesa x (Heck x Chianina)), photographed in the Lippeaue in 2017

170cm is a very satisfying size as it represents the average bull aurochs size for the Holocene according to van Vuure 2005. Also, it makes it bigger than most primitive cattle breeds. With these measurements, Margret Bunzel-Drüke and I concluded that the average size for Taurus bulls is between 150 and 170 cm, and for cows 150 cm, making Taurus cattle the largest cattle in Central Europe. Heck cattle are only 140-145 and 130-135cm tall, thus the attempt to achieve an aurochs-like size range by crossing-in large and very large breeds was successful. 

42 623 is a cross between Churro, the Sayaguesa bull, and Ludovica, a Heck x Chianina cow. 

Turf cattle

Recently I did a reconstruction of a turf cow based on a photo taken by Markus Bühler who presented it on his blog Bestiarium in 2012. 

Turf cattle are an extinct type of domestic cattle in Europe during the Neolithic. Domestic cattle in historic and prehistoric times tended to be much smaller than today, and turf cattle are a particularly drastic example for that. Their shoulder height was probably below one metre, making them as small as modern Dahomey cattle or even smaller. 

The gracile legs of the specimen are almost goat-like. The cow still has a small hump, so its body shape was not that derived as in most cattle today. 

There are no studies on their relationship to modern domestic cattle that I know of. It could be that they stand outside the modern domestic cattle family tree, or belonged to the same branch as modern European domestic cattle. The breeding associations for Braunvieh, Grauvieh and other alpine breeds claim their breeds descend from turf cattle, which is not based on any facts as far as I know. 

Hybridization with wild aurochs might explain the very small size of the smallest reported female aurochs with a withers height of only 112cm[1]. 

[1] Schibler et al.: Incorporation of aurochs into a cattle herd in Neolithic Europe: Single event or breeding?, 2014.