Controlled hybridization for saving the wisent?

For an update of my take on to this subject, go here. 

Long-term readers of this blog will know that the second large wild bovine of Europe, the wisent, is an animal that is not only very spectacular to look at but is also immediately threatened by its extremely low genetic diversity. I covered this topic in several posts already (Overpurity as a danger for the wisent, Donate for the Wisents in the Caucasus and What to do with the wisents in the Caucasus). 

I also repeatedly emphasized why I see the hybrid wisents in the Caucasus as a chance instead of a threat, and I also already introduced the idea of controlled hybridization with American bison in order to increase the genetic of the wisent. This is of course a provocative idea that sounds risky, but I have my reasons and I consider a careful way how to put it into practise worth a try. This is what I want to explain thoroughly with this post. 

The problem 

Inbreeding basically leads to a reduction of genetic diversity, which in turn leads to an increase of homozygosity in the genome. As long as the genome is purged off deleterious (harmful) alleles in the process a high level of homozygosity does not necessarily affect the healthiness of the population (such as in Chillingham cattle), but when the fixation of the alleles is coincidental, such as in the case of a population crash, the consequence is that a lot of deleterious alleles suddenly have a high chance of becoming fixated homozygously in the population, causing them to express their effects in the phenotype and thus leading to a so-called inbreeding depression. The consequences are increased frequency of diseases or distortions that can pose a long-term threat for the survival of the population. This phenomenon is well-known, not only to geneticists, and is a problem in the conservation of animal breeds and species.

The wisent is such a case. Due to habitat destruction and hunting, the population crashed at the beginning of the 20^th century, and all living individuals descend from only 12 individuals. Nowadays, the inbreeding coefficient in the population is very high in both lines (the Lowland line and the Lowland-Caucasian line; the latter one partly descends from the last bull of the B. b. caucasicus subspecies). The inbreeding depression affects skeletal growth leading to skull asymmetry, deformation of the male gonads, increased rate of stillbirths, decreased female fertility and a reduced resistance against diseases and parasites. Wisents are particularly vulnerable to posthitis and balanoposthitis, foot-and-mouth disease, cattle tuberculosis, bluetongue disease and others [1]. Epidemics are an acute danger to wisent populations, both in the wild (in Bialowieza, 20% of the mortalities are caused by diseases) and captivity (few years ago, the stocks at German zoos crashed because of foot-and-mouth disease). Often, reintroduction efforts fails or experience painful set-backs because the animals are too sensitive to diseases (see the herd in the Romanian Carpathians). This is why the action plan for the conservation of the wisent still sees it in the danger of extinction [1]. The genetic basis is simply too narrow to ensure a long-term survival for the species. 

Possible solutions 

The current conservation strategy for the wisent is to continue line breeding without loosing diversity any further. This will not overcome the inbreeding depression but is an attempt not to make it worse. The only way to overcome the inbreeding depression is to increase genetic diversity by introducing more alleles to the population. Except from “constructing” artificial genetic diversity by altering the nucleotide sequence of extant wisents with genetic engineering (which I do not know of genetically feasible), I see only two possible ways to achieve that: acquiring genetic material from wisents that lived prior to the population crash (pre-bottleneck) and reintroducing it into the modern gene pool, or controlled hybridization with the closest living relative, the American bison. 

            Pre-bottleneck wisents 

The genetic material of any wisent that lived prior to the bottleneck event would probably increase the genetic diversity within the modern population greatly, even if it is only one individual, be it from the 19^th century or anywhere else during the Holocene. It should not be impossible to acquire the full genome of such pre-bottleneck individuals. There are probably plenty of hides, trophies or skeletons gained from wisents during the most recent centuries that should all still contain enough genetic material. Also any skeletal remains from the latest millennia might be well-preserved enough for this purpose. Since it was possible to resolve the full genome from 8000 year old aurochs bones, the same might be possible with wisent remains. Once the full genome of one or more pre-bottleneck wisents is resolved, it would be possible to introduce the differing alleles into the genome of a recent wisent using CRISPR-Cas9 (the same method has been suggested to revive the woolly mammoth based on an elephants’ DNA). One or few individuals from prior to the end of the 19^th century would probably (re)introduce enough “new” (or actually old) alleles into the populations to greatly reduce the effects of the inbreeding depression. The downside of this idea is: a lot of research work has to be done that is expensive and the technique is effortful as well. At the moment all the resources of these “de-extinction” techniques are concentrated on more prestigious animals such as the woolly mammoth, and it is pretty unlikely that anyone would spend a lot of money and effort on reconstructing old individuals of a species that still exists, even tough it would be a crucial step to saving the species. 

            Controlled hybridization with bison  

The second method, crossbreeding with its closest living relative, the American bison, would definitely be less costly and could be started immediately. It has to be said that both species are very closely related, they hybridize readily without any barriers or limitations and there are many authors that list them as one species. I am not suggesting to just rampantly cross all wisents on this world with bison and to swamp the whole population with bison genes. Not at all, this would be a huge mistake that would lead to the extermination of genuine wisents on a genetic level. What I am suggesting is wise and moderate hybridization followed by selective absorptive breeding on a separate, new breeding line with a separate herd book. The ancestry of each of these individuals would be documented just as that of the pure individuals. By this way, the population of the pure but inbred wisents on this world would not be affected or threatened in their genetic integrity in the least, only a few starting individuals would have to be “sacrificed” (if you would start with say, only 100 individuals, I bet this number would be still less than all the losses in the global population caused by inbreeding effects each year). 

The ultimate goal of the hybridization and subsequent breeding would be a population where the frequency of the deleterious alleles has been considerably reduced without affecting the biological integrity of the species too much by bison alleles. The deleterious wisent alleles affect development and other health factors and are probably not crucial for defining wisent characters. Thus, replacing them with alleles from bison would have a beneficial effect on the development and health of the individuals without affecting their nature as Bison bonasus. Of course hybridization will introduce any alleles of the American bison, which is why some sort of controlled breeding is necessary.  In the end, the animals would have to be indistinguishable from other wisents in morphology and looks, behaviour and ecology but at the same time not suffer from the same effects of the inbreeding depression as their conspecifics do. 

The American bison is subdivided into two subspecies, the plains bison Bison bison bison, and the wood bison Bison bison athabascae. Both subspecies are different ecotypes and have different phenotypes. The wood bison is more adapted to woody habitat, is better adapted to cold and is phenotypically not a far removed from the Wisent as the plains bison. So it would probably be wiser to take wood bison for the hybrid project. 

See here for a comparison between wood bison (left) and plains bison (right). As you see, the wood bison also morphologically resembles the wisent better than the plains bison. 

How to execute such a project 

The larger the initial gene pool the better of course. It would be easiest to start with a herd of bison cows and put a wisent bull on it, but the purpose of the project would be to gather as much wisent diversity as possible, so it would be wiser to start with a herd of wisent cows (20 would be minimum I would say, 100 would be ideal) and put a bison bull on it for the first round. After that and when all cows produced 50% bison and 50% wisent individuals, the American bull would have to be replaced with a wisent bull. The half-wisent individuals would be backcrossed with a pure wisent, which is called absorptive breeding. In order to gain maximum diversity it would be best to replace the wisent bull in each round, although this would be incredibly effortful and costly. This would have to be continued until 1/8 or 1/16 bison individuals are born. Depending on how strongly the bison influence shows, one of these advanced hybrid individuals could be chosen for breeding. I would only take bulls where the hybrid influence is phenotypically as much as undetectable. This is now where the real deal is going to happen: breeding between individuals that both have hybrid ancestry. Only the mating of two wisent that both have hybrid ancestry can enable the true purge of deleterious alleles from the population and the fixation of healthy alleles. The hybrid wisent bull would mate with the pure wisent, half-wisent, quarter wisent et cetera that are present in the herd. Personally I would phase out the individuals with a high bison percentage in this stage. When there is a good mix in the population with all individuals having a high wisent percentage in their genome, phenotypic selection can begin. It would be necessary to remove well-mixed individuals that have a clearly visible hybrid mark in their morphology and external appearance, or show bison behaviour such as head-butting in combat fights (wisent fight horn to horn like cattle). Factors such as food choice could also be evaluated, as bison are more heavy grass eaters than wisent, while wisent also like to browse and peel trees. Another round of pure wisent backcrossing might be necessary in order to get the wisent percentage in the individuals as high as 95% and higher. 

 

A schematic illustration of absorptive breeding

After couple of generations, the wisent would hopefully be virtually indistinguishable or even completely indistinguishable from pure conspecifics (there would be some individuals with bison traits popping out on occasion as usual in breeding, selection would have to wheedle that out in the long term run). What would be crucial now is actually the main purpose of the project after all: studying whether these wisent with bison introgression are truly more healthy and evolutionary fit than their inbred conspecifics. If my expectation is right, symptoms of the inbreeding depression such as stillbirths, infertility, developmental disorders and asymmetries must have decreased in frequency or maybe completely disappeared. Also, they would hopefully be less prone to the typical inbred wisent diseases. If kept under semi-natural or natural conditions, it would be very interesting to see if the survival rate in winter is higher than in Bialowieza, where most of the wisent die of the usual diseases that are plaguing the species. 

If the wisent with the controlled and selected bison introgression are truly healthier and more evolutionary fit than the pure but inbred ones, and indistinguishable from pure ones at the same time, the project could be called a success and the wisent would finally have a perspective for an ensured healthy long-term survival. 

A herd book 

Setting up a herd book would be essential in order to carry out the project in a professional and transparent manner. It would be separate from the international herd book for pure wisents, and it should mark not only the genealogy of the individuals themselves but also their genetic composition, f.e. 25% Bison 75% Wisent. Perhaps also if both parental sides have hybrid ancestry or if it is merely a back-cross. In this way, the introgression project would be absolutely transparent, controlled and documented, and there has to be no fear of a rampant, irreversible swamping of the wisent pool with bison genes. Especially since all evidently pure wisents are listed in the official breeding book for the species anyway. 

A breeding book for wisents with introgression from bison also opens possibilities for the Caucasus population, which descend from hybrids with plains bison. While there are voices that want to cull them all (f.e. such as the international wisent conservation action plan), the population could be regarded as being of considerable worth as it is the only large wisent population with a long history of living in the wild under natural selection on this world at the moment, and the bison hybridization increased their genetic diversity and probably also evolutive fitness.  A few herds of these individuals could be taken and bred in European conservation projects, but registered in a breeding book. That is where the hybrid project’s breeding book could be an option for the recognizing of this population as something of worth for conservation. A second section in the hybrid breeding book could be set up for this particular genetic line (the plains bison hybrids from the Caucasus), and the largest concern of the opponents of introgression in order to safe the wisent, the danger of confusion with pure wisents, would be refuted as everything is transparent thanks to the herd books. As the Caucasus wisent still show phenotypic vestiges of hybridization (if you take a close look, you see that they are somewhere intermediate between bison and wisent), they could be back-crossed with wisent again. In the long term run, it could even be considered to fuse both the wood bison hybrids and the plains bison hybrids in order to gain maximum genetic diversity. 

A hybrid herd book would also be a prospect for those wisent not registered in the official purebred herd book. There are about 700 individuals not registered because their pedigree is not proven or documented. A number of them might have hybrids with bison or cattle in their ancestry, a number might be pure but not documented. Anyway, conservation acts as if those 700 wisent would not exist, despite it is a considerable number and some of them might be more healthy than those in the official herd book. Ignoring them completely is maybe not wise. They could be included into the hybrid herd book as well, in the form of a third section. 

References 

[1] Mammal Research Institute, Polish Academy of Science: European Bison Bison bonasus: Current state of the species and an action plan for its conservation. 2002

Second-generation Auerrind crosses underway!

After my portrait of the two subadult Auerrind bulls, Claus Kropp told me that Alvarez the Sayaguesa x Watussi bull has already inseminated the Sayaguesa x Grey cattle cow and soon will be brought to the herd of Chianina x Sayaguesa crosses. I am extremely happy to hear this as this not only means that next year we will see the birth of the first second generation Auerrind, but also that the very promising combination (Sayaguesa x Chianina ) x (Sayaguesa x Watussi) will be realized. 

The (Sayaguesa x Watussi) x (Sayaguesa x Grey) sounds promising too. It surely will have a lot of Sayaguesa characteristics, and also the potential for long and large horns on both parental sides. Thanks to Grey cattle, the winter coat has the potential to be rather good. 

I was also told that the first Chianina x Watussi have been born. This combination will also be used as a partner for Alvarez in the future once the newborn individuals are sexually mature. I am looking forward to see how this combination will turn out, and true F2 Chianina x Watussi would certainly be also worth a try (they would even have the potential for a perfectly aurochs-like colour: Watussi removes the dilutions, Chianina contributes the allele for E+ and black pigment, possibly even some degree of dichromatism masked under the dilutions). 

Now the project is really coming on, it is great to see it progressing with each year. A herd book exists since 2015, which is important for keeping track of the offspring. 

Two Auerrind bulls

Today I want to cover two of the most significant Auerrind bulls that are around so far: the Maremmana x Watussi bull Apollo and the Sayaguesa x Watussi bull Alvarez. Both are now old enough to deliver an idea what their body shape and horn shape is going to be like when fully grown, and their coat colour is final as well. 

 

© Auerrind Projekt

Apollo 

© Auerrind Projekt

The Maremmana x Watussi bull is exactly intermediate between its both parental breeds in looks. Alternatively, it looks like a red Maremmana bull with really thick horns. The body shape does show Watussi traits, but the zebuine hump is only very small. The horn shape is elegant with pointed tips and looks a lot like those of some Heck cattle of the Wörth lineage, which is not surprising as both share Watussi ancestry. It is larger than the grown pure Pajuna bull, but Pajuna is a small breed. 

Alvarez 

© Auerrind Projekt

© Auerrind Projekt

The Sayaguesa x Watussi bull is one of the combinations I was looking forward the most and it is very exciting to see this guy grow. The colour turned out perfect, it seems to have no zebuine hump or at least a very small one, the body shape is Watussi-influenced but not as sausage-like as in Apollo. The big question is how its horns will turn out – how large they will get and which curvature they will have. As the bull is still quite young but the horns have a large diameter at the base, I guess they might grow large to very large. 

Having had a look at these bulls it is of course fun and exciting to think about what kind of cows they could be bred into in order to produce good results. If Alvarez would be bred to a pure Sayaguesa cow, with look the result (75% Sayaguesa, 25% Watussi) would be very satisfying already. Bred into another one of its kind, the resulting true F2 has at least a chance to be stable for the desirable traits. One could also breed Alvarez to one of the Chianina x Sayaguesa cows, in order to have more genes for large size and long legs in the mix. Producing true F2 with this combination ((Sayaguesa x Watussi) x (Sayaguesa x Chianina)) might be promising. 

For Appollo, finding the right combination for promising offspring in the first generation is more tricky. One of the Sayaguesa x Chianina cows might be a worth a try concerning body size, horns and overall shape, although there is a high chance that the colour would be diluted (what would not be that much of a problem to me as colour is comparably easy to breed because it is controlled by only a few genes). 

The Auerrind project’s aim is to produce more stable results by using true F crossings (for the F-terminology, go here). I don’t know if this means that they would strictly cross only the breed A x B crosses with the same of their kind, or of they would also allow (A x B) x (C x D) and continue line breeding with true F of these combinations. I think this might be more efficient, as none of the cattle breeds selected would combine all aurochs traits in a two-way-combination. 

On the photo below you see Apollo, Alvarez and the fully grown Pajuna bull that joined the Auerrind project last year. I am happy that Pajuna has been included in the programme, although I do not know any efficient cross combinations with Pajuna in this selection. Maybe it can help to increase volume at a later stage of the project. 

© Auerrind Projekt

Indian vs. European aurochs portrait

I have done a couple of posts trying to investigate what the Indian aurochs looked like, including illustrations (go here fore the latest). The problem is that it is rather speculative as there is not a single more or less complete postcranial skeleton nor are there any sources concerning its fur colour. However, at least concerning the head we can be sure as there are a couple of complete crania preserved. Using one of the rare photos of a cranium of Bos primigenius namadicusI did a head portrait compared to that of a European aurochs bull based on the Berlin skull. 

You can clearly see the cranial differences that are evidenced by the bones. The Indian skull is much more sleek and narrow, while the European one is more massive. The Indian skull has a frontal area that is broader than the distance between the orbitals. The horns are way more longer and more wide-ranging, not necessarily more upright than in the Berlin specimen. These are the hard facts dictated by the bones. 

All the other differences between both aurochs on my drawing are inferred from deductive reasoning and comparison with primitive taurine and zebuine cattle. For example, curly forelocks are proven by historic evidence for the European subspecies and most domestic taurine cattle have them, at least the bulls. For the Indian aurochs, there is no evidence on its pelage, but there are not any zebuine cattle on this world that have curly forelocks (at least no purebred ones). In many wild bovids, those living in temperate climate have some kind of ornamenting fur traits such as manes and beards (see bison and many goat and sheep species), while those in tropical climates have short coat and fleshy appendages such as a dewlap instead. This is why my Indian aurochs has no curly forelocks but a slightly larger dewlap than the European one – thermoregulation being another reason to consider a larger dewlap and a bit more wrinkled skin for the Indian subspecies. 

Also, I chose to give my Indian aurochs the ear shape of zebu cattle, and used a Watussi individual for reconstructing the face shape, so that the aurochs looks “zebuine” (but not domestic, f.e. I consider the hanging ears of zebu cattle a classic domestic trait). 

I think those drawings are plausible reconstructions for subspecies inhabiting tropical and temperate climate, respectively. 

Watussi-influence in Heck cattle: Fact or myth?

After a couple of months of silence here, I am back with a number of posts in preparation. For now, I want to look into the Watussi influence in modern Heck cattle. 

Many large-horned Heck cattle have their long and thick horns thanks to the influence of the half-zebuine breed Watussi, which is remarkable its the huge horns with a remotely aurochs-like curvature. This is a note I have made many times on my blog, and is also found in numerous literature sources. However, some Heck breeders deny (or have been denying) the influence of this rather exotic breed in the otherwise exclusively European breed that aims to mimic the extinct European aurochs. With this post I want to look into the historic evidence for Watussi influence in the Heck cattle pool and also into the arguments against it raised by Heck cattle breeders, and finally why I am 100% convinced of the truth of Watussi influence for the large-horned Heck cattle lineages. 

Comparison: large-horned Heck cattle vs. standard Heck cattle 

Heck cattle descending from the putative Watussi cross are found in the Neandertal herd and the Frisch breeding line (which is derived from the former) plus all their descendants. As both were and are rather influential for other herds, this also goes for a large portion of the Heck cattle population in central Europe. All those herds have horns with a volume (and also curvature) more aurochs-like than others on average. This is especially true for the Frisch line (Insel Wörth being the former breeding locality), as the breeders put a special focus on improving the horns in this herd. 

There are also Heck cattle herds that have no influence from these two lines, and their horns are never spectacular, neither in volume nor curvature. Here is a comparison of one of the best Heck bulls from Wörth, Aretto (Photo by Walter Frisch, I hope it is ok for him that I use his photo), and a standard Heck bull from Hellabrunn, which resembles the original Heck cattle bred by the Heck brothers very much: 

You clearly see differences, not only in the horns. I will cover that later on. 

Documentation of Watussi influence in the herd book 

The international herd book of Heck cattle lists a cow named “Antje”, born in 1952 in the Duisburg Zoo, for which a father is remarked as “Watussi” and a mother remarked as “Aurochs” in the herd book. Some Heck breeders claim that those names listed in the Herd book were just names for the individuals themselves, and not the breed identities. Thus, the father would have been a Heck bull named “Watussi”. But it is important to note that “aurochs” was (and still is) being used as the breed name for Heck cattle by Heck cattle breeders, also in the herd book. If those terms were just individual names, it would be like listing father and mother in a Golden retriever breed book as “Golden retriever” and “German Shepherd”. This would be rather unlikely. 

Regardless of the identity of the individual Antje, whether it was a pure Heck cow or half-Watussi, it was sold to the Wildgehege Neandertal, where it produced three cows and one bull named “Nuck”, which was subsequently used as a breeding bull in the herd. Assuming that “Watussi” in the breeding book was indeed a Watussi, Nuck and its sisters would have been 25% Watussi. Together they would produce F2 of this combination, and with its mother it would have produced 1/3 Watussi Heck individuals. This would be plenty of genetic influence in the herd – if just consistent back-crossing with Heck cattle happened, the Watussi-influence would have been reduced to nil rather quickly. By using the quarter Watussi bull as a breeding-bull, it could be the case that many individuals of the herd during the 1970s and 1980s still had a influence by Watussi that was not undetectable in phenotype and considerable in percentage – one would have to research precisely in the breeding book. The Neandertal herd, due to its quality in colour and horns, influenced many other herds in Central Europe during the 20^thcentury, including the Frisch herd, which was formed mainly by individuals from the Munich zoo and the Neandertal. The Frisch lineage is the Heck cattle lineage with the mightiest and best-curved horns (see here). The absolute and relative dimensions are very satisfying and surpass all other Heck cattle herds on this world, thanks to intense selection and the good basis from the Neandertal herd. Its influence on many other Heck cattle herds, especially in Southern Germany, is easily detectable when looking at the horns.

Considering that the original set of breeds chosen by the Heck brothers does not show any focus on large and thick horns but is rather dominated by breeds with medium-sized to small sized horns (Angeln, Werdenfelser, Corsicana etc.) and that even those with the largest horns of this selection (Grey cattle and Highland) never have such spectacular horns, and – more importantly – Heck cattle outside of these lineages never have really large, thick horns, it is rather suspicious that one important founding cow of these two exclusively large-horned lineages has a father listed as “Watussi” in the herd book. If indeed “Watussi” was just an individual name chosen for a pure Heck bull, which would be a rather curious name choice, the coincidence is huge that its descendants turn out to be Heck cattle with considerably larger horns than Heck cattle not descending from it. 

This makes it very likely that the bull named “Watussi” in the breeding book was indeed a Watussi bull. Therefore, the influence of the large-horned Watussi breed in Heck cattle is documented in the breeding book and probably responsible for the increased horn volume in the breed lines descending from it. 

The phenotype 

Apart from the horn size, there are other morphological traits that support a Watussi ancestry for the large-horned Heck cattle lineages. Comparing the photos of the two bulls above, the bull from Wörth, with the documented Watussi ancestry, also has a trunk that is slightly more sloping than the rather rectangular trunk of the classic Heck bull, resembling the “sausage-like” body shape that is typical of zebuine breeds, formed by a sloping back and a more down-turned pelvis. The differences in trunk shape are not due to perspective, it is visible on many photos. Also, some Heck cattle of the Neandertal-Wörth lineage and their descendants have slightly hanging ears (f.e. the bull Nestor used in the Lippeaue), which is also probably inherited from Watussi. The horn shape of Aretto is 100% identical to that of many Watussi individuals. Also, the skull shape and shape of the face is somehow reminiscent of Watussi (zebuine breeds have a somehow different face than taurine cattle, it is hard to describe it, but the differences concern the nose, eyes and snout shape). 

All in all Aretto indeed looks as if it was a cross between a normal Heck bull like the one above and 1/8 or 1/4 Watussi. 

There are also a lot of other large-horned individuals descending either from the Wörth lineage or the Neandertal herd that show traits very reminiscent of Watussi. The faces of this bull and this cow, for example. There is also a bull kept in Baden-Würtemberg that has all the vestiges of Watussi ancestry in one (face shape, hanging ears, sloping pelvis, colour), it is unfortunately not online anymore. The zebuine/Watussi influence in this cow at the Schwarzwald, which is probably from the Neandertal herd, is very obvious right from the first glimpse. Also, some of the very large-horned Heck cattle have an interesting colour with a slightly purple shine and a very orange colour between the horns. As Watussi have a very rich wine-red colour, this too might be a result of Watussi alleles. All individuals that show this colour also have other suspiciously Watussi-like morphological traits. 

In my opinion, the influence from Watussi cattle in large-horned Heck cattle is historically documented and very obvious from unambiguous morphological traits. Take a look at the bull at 0:53 and 1:51 in this video: with the shape of its face and trunk, the slightly hanging ears, the wine-red shade in its colour and of course the very thick horns this bull cannot deny its Watussi ancestry. 

However, I do not think this is a bad thing per se. Watussi obviously helped to improve the horns greatly, and it would have been difficult to achieve that with a taurine breed. The fact that zebus are a different subspecies is, in this case, only a nomenclatural problem to me because I am looking only at the genes. And those vestiges of zebuine ancestry (ears, sloping body) are undesired domestic traits that just have to be bred out like any other trait (f.e. see the many different colour variants found in taurine cattle, that would have been added to the pool if Texas Longhorn would have been used instead of Watussi). Summa summarum, it does not lower the quality of large-horned Heck cattle as a “breeding-back” result in my opinion. I would use the good individuals like Aretto or Erni at any time for a breeding project. 

But there are voices against using Watussi for horn volume in “breeding-back” because it is a half-zebuine breed with obvious zebuine traits that would leave a strong mark in the otherwise taurine populations. My argument against this concern is that Heck cattle is an example for using Watussi for horn volume without altering the taurine nature of the breed. Apparently this was not 100% correct as there are some zebuine vestiges visible on occasion in the breed. However, I still do think that my argument is valid, and that there will not be much if any visible zebuine influence in breeding projects using Watussi, such as the Auerrind project or Hungarian Taurus cattle, if bred carefully because the breeding mode there is different: in Heck cattle, we had a herd with a part-Watussi breeding bull that had backcrossing with part-Watussi individuals. In the other projects you still have active crossbreeding with several different breeds, where there can be a constant supply with new genetic material and selection would have to focus on keeping the alleles that contribute the large horn volume and loose the alleles typical for zebuine breeds or Watussi. 

On the other hand, there still is genetic linkage – maybe this kind of fractioning the alleles is not entirely possible because the alleles are linked on the same chromosomes, and this could even be the reason why Watussi influence is still visible in large-horned Heck cattle – the genes might be linked. Nevertheless, only practical breeding can show what the results are going to look like, I am still very fond of carefully using Watussi in “breeding-back” and am looking forward to see more results of that. 

New Auerrind herd, with photos!

The Auerrind project announced the start of a new breeding herd in Frankenstein, Germany (yes, there is a village called Frankenstein) this week. It is composed of the Watussi x Maremmana cow, a young Sayaguesa x Chianina bull, and two Tauros cows from the Netherlands. 

Here are some photos: 

© Auerrind project

Watussi x Maremmana cow © Auerind project

Sayaguesa x Chianina + the half-Watussi cow © Auerrind project

It is very interesting to see these two individuals growing. The Watussi influence in the cow shows rather strongly (which is not a bad thing considering it is an F1), partly possibly also because Podolian cattle have massive zebuine influence anyway. The colour is good and the horns will surely grow very large. The Sayaguesa x Chianina bull seems to have a diluted colour (the phenotype of an F1 is, from the technical view, not relevant for further breeding on qualitative traits). Bulls of this combinations show all possible colour variants between almost white and perfectly aurochs-like, which is peculiar considering that both parental breeds have a uniform phenotype (my possible explanation is that Chianina might not be all homozygous on the diluting loci despite its uniform phenotype, but that is only a suspicion). 

A robust aurochs

It often happens that my aurochs reconstructions might turn out a bit too lightweight. I always use original skeletons for the proportions, but I think it is possible that I underestimate the amount of soft tissue on the skeleton for fully grown adult aurochs. So also in my new aurochs model. It should be anatomically correct as it is based on multiple specimen, but it might be a bit too gracile on the soft tissue anatomy for a fully grown bull. 

So I took one of the photos of the model, tracked it out and finally did a truly massive aurochs specimen as far as the skeleton allows, and used extant wild bovines, especially wisent, as an analogue. This is the result: 

I think that fully grown, old and solitary aurochs bulls might have looked like this. There is an Italian cro-magnon stone carving that might show such a bull, which is portrayed as a pretty robust specimen (here). 

I think that an aurochs skeleton does not allow much more mass. The model is based mainly on the Sassenberg bull, which is described as an almost senile specimen because of its extensive tooth wear. So fully grown aurochs probably did not get much more massive than that, it simply was a comparably gracile species apparently. 

The Lippeaue herd's new web presence

The Lippeaue Taurus cattle population, which represents the top-level of quality for Taurus cattle breeding or perhaps aurochs-like cattle in general, now has a new and extensive web presence on the website of the ABU. 
I covered the Lippeaue herd in a lot of articles on this blog already, as I visited it in 2013, 2015 and 2017, and used it as a case-study for many aspects of breeding aurochs-like cattle. 

Now you can also use the website of the ABU to get some information and photos about the herd. It introduces the founding breeds, the results of 29 years of breeding and a selection of important individuals of the herd, with lots of photos. 

A classification for Heck cattle

What kind of cattle breed is Heck cattle? Of course it is a “breeding-back” result. But how would we classify this breed if the concept of “breeding-back” would not exist and letting only the breed and its history speak for itself? 

Heck cattle are “normal” cattle 

Most important to note is that Heck cattle are “normal” cattle. By that I mean it is not dedomesticated (it does not have a feral ancestry/history), it is not anymore wildtype-like in behaviour, survival capacity, robustness or morphology than the so-called primitive breeds and it is also, of course, not a reconstructed aurochs. Nowadays barely anyone believes that, but when I started getting interested in “breeding-back” these myths were quite present on the internet and literature. Also, Heck cattle is neither an aggressive cattle breed nor the most aggressive breed known. This is simply not correct, despite all the lurid tabloid articles claiming the opposite. It is a robust breed, it is a healthy breed, it an aurochs-like breed but it certainly does not have a special status among all cattle breeds on this world and is not any less domestic than other cattle. 

What is Heck cattle based on its breeding history? 

It is often claimed that Heck cattle was bred using old and primitive cattle breeds from various places of Europe. In reality, however, Heck cattle is a mosaic breed of both more or less primitive breeds and derived breeds. Central European milk breeds actually played a considerable role in the creation of Heck cattle, including Braunvieh, Murnau-Werdenfelser, Angeln and Black-Pied. And the influence shows indeed: many Heck cattle bear striking resemblance to Murnauer, Angeln or Braunvieh and there are occasionally individuals showing white spots. It was mainly Corsican, Steppe and Highland cattle that contributed the “archaic” look. Heck cattle is therefore not all that exotic based on its ancestry but rather of mostly Central-European descent into which breeds from other regions have been crossed in. 

Heck cattle is, in my opinion, indeed more of a mosaic population rather than a true breed. It was created by more or less rampant crossbreeding of at least six breeds and the influx of very few afterwards, started from a small population of only a few dozen individuals that never had a uniform phenotype and were fragmented and spread among whole Germany respectively whole Europe afterwards. Some herds have been barely bred selectively since then, others, like the Wörth/Steinberg lineage created by W. Frisch, experienced rather intense selection. The consequence was a very heterogeneous population that displays a large degree of variability in morphology and also behaviour. Each herd shows a different spectrum of possible trait combinations. Some individuals bear a great resemblance to the founding breeds, and the genetic portion of the founding breeds obviously varies from herd to herd. Occasionally some individuals are very reminiscent of the founding breeds; some individuals are virtually indistinguishable from Hungarian Grey cattle for example (see the individual at 3:19 in this video). More advanced Heck cattle, however, are already a morphotype on their own, such as these individuals here. The degree of aurochs-likeness is just as variable as the breed itself, some individuals are rather good from a “breeding-back” perspective (f.e. here) while others are not (f.e. here). 

Is Heck cattle a landrace? 

Heck cattle is a robust, healthy and climate-resistant breed that is well-adapted for European nature systems. Does that make it a landrace? Poettinger 2011 does classify it as a landrace. A landrace is by definition a locally adapted variety of domestic animals that were not consciously created but just happened to evolve, experienced little artificial selection but instead were shaped by the natural factors they were exposed to. Landraces tend to be less uniform than normal breeds, more robust and resistant to nature in their local environment. They are somewhere in between a totally artificial breed and a feral population. About half of the breeds that Heck cattle was bred from can be considered landraces: Highland cattle, Grey cattle and Corsican cattle, while the other breeds would not necessarily fall under that definition.  

Heck cattle is as robust, healthy and adapted to the environment as a landrace, but I would not classify it as such because of its history. It was artificially created in a very protected environment (zoos and private farms) in the first half of the 20^thcentury by crossbreeding landraces and derived breeds and subsequently was mainly kept in those protected environments. It has the same survival capacity as a landrace, but it is not a landrace itself. From the 1980s onwards, an increasing number of Heck cattle were kept under semi-natural conditions and being able to live under these conditions is a requirement in these populations. Nowadays, about the half or even the majority of the total Heck population are kept this way. Some of them, like those in some Dutch reserves, have been living that way for a couple of decades now. Under these conditions, those Heck cattle can become, so to say, a “controlled” landrace that was created consciously and that is also selected upon. Those herds that have been living in zoos or on private farms ever since would have to be excluded from this status. The herd in Oostvaardersplassen, which has been self-sustaining without any human interference for almost 40 years now, is even on the brink of becoming a feral population, and the process of dedomestication is definitely beginning and visible (see here). 

In a nutshell: a classification for Heck cattle

Heck cattle is a very plastic population of cattle that was created from a mix of less-derived landraces and derived breeds and is very variable not only in appearance and behaviour but also in the way the herds are kept; some are kept under completely artificial conditions in zoos and on private farms, others live or have been living under semi-natural conditions and one herd is in the process of becoming a feral population. Heck cattle is a breed that was created consciously by breeding, the selective pressure put upon the herds was nonexistent in some lineages to very intense in others, and not only the phenotype but also the husbandry conditions are very versatile in this population. This makes it neither comparable to a true landrace nor to a true breed, but rather a mosaic population. 

The Heck bull Aretto vs. aurochs

Taking aurochs reconstructions and using them as a direct comparison for living cattle is very helpful for judging their aurochs-likeness. It is way more effective than just eye-drawing and you see all differences at once. I think that my new aurochs bull model is very suitable for this job. I invested a lot of time into making it as scientifically correct as possible and I think it represents an authentic picture of a mature male aurochs from the Holocene of the northern half of Europe. 

In Walter Frisch’s Der Auerochs (2010), there is a photo of the Heck bull Aretto in a very similar stance, and I made a photo of my model from the same angle in order to compare the Heck bull and the aurochs reconstruction directly to each other. The photo of the Heck bull is copyright by Walter Frisch, please do not use it without permission and I hope it is OK for him that I present it on the blog here. 

Aretto  is a bull from the breed line of Walter Frisch, which is a strain that has been excellently. Members of this lineage often have superb horns, especially in dimension, the colour is ok and the bulls often have a shallow hump. The body, however, is quite normal by Heck standards. Aretto was one of the best bulls of this herd, so it is very interesting to compare this individual to an aurochs. 

 

Aretto ©Walter Frisch.

Aurochs bull model

Body size:The aurochs type that my model is based on is 175cm tall at the withers on average. The size for Aretto is claimed to be 160cm in the literature, but I visited the herd myself in 2013, and I consider 140-145cm for grown bulls of this lineage more realistic (I am open to be proven otherwise). So there is a considerable size difference.

Proportions:The proportions are totally different. The head is much smaller, the legs much shorter, the neck is shorter and the trunk more elongated in the Heck bull. 

Body shape:The muscling in the Heck bull is reduced, while the intestinum is greatly enlarged, and the spine of the trunk is also slightly hanging. The hump size is noticeable reduced. 

Head:The small head in the Heck bull is paedomorphic with a short snout (not that visible on the photo). 

Horns: The horns of the Heck bull are similar to those of the aurochs, but they look as if they were pulled outwards and upwards. Their size is smaller than in my aurochs, but there were certainly also aurochs with horns of this particular size. The thickness of the horns is similar to that of an aurochs’ horns. 

Appendages:The dewlap and the scrotum are greatly elongated. 

Colour: The colour is more or less identical, except for the fact that the Heck bull inherits a less-pronounced sexual dichromatism.

All in all, you see that the Heck bull is a rather ordinary domestic bull concerning body size and morphology and that the similarities are actually restricted to colour and horns. There would of course also be differences in behaviour between a wild aurochs and a domestic individual (f.e. stress response, lethargy/alertness etc.). This does not alter the fact that Aretto, and the Frisch lineage in general, are superb breeding results as they belong to the most qualitative Heck cattle herds around and I would use them for “breeding-back” at any time. 

Despite the morphological differences, I believe that a population of Arettos would look and behave indistinguishable from wild aurochs after 100-200 years of natural selection due to dedomestication, apart from size probably. 

More of these comparisons between the aurochs model and living cattle are to come. 

By the way, when looking at this photo of Aretto, I think it is possible to detect the Watussi influence that is documented for the Neandertal/Frisch lineage (which is, per se, not a bad thing in my opinion), but more on that in a future post. 

Aurochs model: finally finished!

(Disclaimer: The photos below and the aurochs bull model are my property and I acclaim copyright. If you use them without permission as it happens all too often, I will get very angry.)

My newest aurochs model is finally finished. It took me six months because I am a horrible perfectionist, but it paid off: 

It is made from air-drying modelling clay and was painted with acrylic colours. It measures exactly 33cm at the withers and therefore is in 1:5,3 scale to a 175 cm tall aurochs. 

The source material for my model were qualitative photographs of mounted skeletons and skulls. The production sketch it was based on is my latest aurochs reconstruction drawing which is based mainly on the Sassenberg bull skeleton with elements of the Kopenhagen bull. The reference is therefore a male Bos primigenius primigeniusfrom the early Holocene of the northern half of its range. Other specimen that I used as a reference, especially for horns and skull, were the Berlin skull and the London skull. I consistently checked simply everything: the proportions, the shape of the trunk, the diameter of the legs, the diameter of the horns (I sculpted the bony cores first), the length of the horns, the width of the skull at the level of the eye sockets, horn base, snout etc., so everything should be perfectly in accordance with the reference specimens. (before anyone makes comments like “I doubt the legs were always that long”, “I think the size of the horns is exaggerated” or anything like that: guessing by eye is always nice but I built my model by measuring multiple specimen and using original sources, so the proportions should be right; the only variable is the amount of soft tissue that I put on it;  I might have made it still a bit too light for a fully grown bull, an error that often happens to me because I like to stay on the safe side, but the morphology is still plausible nevertheless). It was also very interesting that often when I calculated how large the head or how thick the legs should be, I at first thought “15 cm, no way, that is too large”, but when I the sculpted the shape I saw it worked out fine. 

The horns were tricky because I had to decide which size and orientation relative to the skull I would like to chose (for the curvature, I chose the most common one). Horn size varies greatly in aurochs, and also the orientation relative to the skull (from 40° in the oldest aurochs specimen to 90° in the Vig skull). Since my aurochs is based on early Holocene northern Eurasian aurochs, I had a look at photos of skulls from this age and region (Sassenberg 65°, Lund 60°, Kopenhagen 50°, Vig 90°, London 70°, Berlin ~65°, Baikal 70°) and chose for the average, 65°. The interesting thing is that the bony cores in my model did have an orientation of 65° degree relative to the snout, but when I added the horn sheaths, it changed to 70°. So the optical orientation of aurochs horns might differ between skulls and in life. 

For the horn length, I took the London, Baikal, Sassenberg and Berlin skulls as a reference. For a 175cm aurochs, the horn cores as large as in my model would be about 93cm, with sheaths 118cm. This on the larger end of the spectrum, but by far not the largest and is in perfect accordance with the fossils. The horn span would be 112cm (this equals those of Heck bulls of the Wörth lineage). That of the London skull would even be bigger. Regarding the size that the sheath adds to the bony cores, I simply took the average of what is given in the literature for preserved aurochs horns and cattle sheaths and what I measured myself on Taurus bull skulls ,which is adding about 30% to the length of the core and 1-2cm (in the real animal) of thickness to the horn. 

Of course I added the curly forelocks to my model, which are well-proven in historic reports and art. I also added the mane for which there is reason to assume its presence in wild aurochs bulls. 

I painted the model with acrylic colours. For the colour, I chose the only colour scheme that is proven for European aurochs bulls: I did not add a light colour saddle as there is no original evidence to assume that European bulls had one, only a solid black colour is proven. The mealy mouth is quite reduced as I think this would have been the case in mature wild bulls. There is also no evidence for a different colouration of the forelocks, although I cannot rule it out completely that this was the case in some aurochs bulls. The horns have a bright yellowish colour, which is based on actual aurochs horns and a Hungarian folklore song that sings of “the urus with its golden horns”. 

Go here, here, here and here to see work in progress pictures.  

Even for the width of the dorsal stripe I relied on original sources. The only source for that is Schneeberger 1602, who writes that the dorsal stripe was “two fingers wide”. Which would be 7mm in the model. When adding the dorsal stripe, I noticed how these light markings contribute to somatolysis in the living animal: 

WIP picture without dorsal stripe

All in all I am very happy with how the model worked out. It worked out exactly the way I wanted and I think it gives a very accurate impression of what a male aurochs from the Northern half of Europe in the early Holocene looked like. A old mature bull could probably have been heavier, but I think Sassenberg bull, Baikal bull, Berlin bull and London bull probably looked a great deal like this in life at some stage of their development. And it also lines up well with my previous aurochs bull reconstructions on paper. 

I think I also greatly progressed from my 2015 model in terms of artistic investment if you judge it on its artistic quality. 

Here you see the result from different angles (the snout profile is not completely straight, as in the London or Baikal skulls): 

Here you see how much perspective plays a role. On this shot, it looks like the model as an S-sloped back with a downturned pelvis like a zebu, although it actually has a straight back as you see on the other shots. Looking at the model, I think it would be hard to achieve aurochs-like horn volume without the influence of Watussi, Texas Longhorn or other very large-horned cattle breeds. 

What a mighty beast. If the aurochs had not been wiped out by mankind, it would probably be considered among the most majestic animals of today, right after the lion. 

Looking at the head from this angle, I get the impression that the horns of large-horned aurochs were a little larger than what is necessary for effective combat. They most likely also served a role in display. 

A 175 cm tall aurochs to a 175cm tall human

On this GIF, you see the aurochs compared to a 175cm tall human with withers heights ranging from 190cm, 175cm and 155cm. It shows what large beasts European aurochs bulls were, especially the giants with 190cm withers height which undoubtedly existed according to the fossil record. 

Thanks to this model I can envision a living, breathing, moving, walking aurochs much better and more complete and precise than before. 

I think it also shows very clearly how much most domestic cattle are removed from the aurochs. To me, it is obvious that from all modern cattle breeds that I know of, breeds like Lidia and Corriente resemble the aurochs the most in terms of morphology (and to a certain degree also behaviour), apart from size. Also, some Camargue have a very good shape albeit being very small. Just compare the photo of the model above with this Lidia, this Corriente, and this Camargue bull. When you look at a classic Heck bull, however, you see that the similarities to an aurochs are obviously restricted to superficial resemblance in colour and horn shape. The rest is ordinary domestic cattle morphology. 

I think that a mix of mainly Lidia and Corriente, supplied with Chianina, Camargue, Maltese, Sayaguesa, Maronesa and a little bit of Watussi for the horn size could result in morphologically very aurochs-like cattle. It would resemble a wild aurochs to a large extent, apart from some ineradicable morphological artefacts of domestication.  

Being motivated by how this model turned out, I am intending to do some more. For example, I want to do some mini busts in the same scales for aurochs heads with different kinds of horn types evidenced by aurochs skulls and horn sheaths. Plus an Indian aurochs bull in order to show the cranial differences. Also, I might want to do a female aurochs for that bull. We will see. After working on a bovine model for six months, my next model plan is a Tyrannosaurus rex, which is not actually relevant for the blog, but I would also like to do a woolly mammoth and a giant moa.  

A little delay

There will be a little delay with the aurochs model because I have to do some changes on it. It was indeed a bit too gracile on the head and neck area when I last posted photos of it. I made the horn tips and the face more massive, then I considered it okay and painted it. When I finally considered it completely finished, I realized that it should indeed be chunkier around the throat and cheek area in order to look really mature. 
I am currently working on these changes, maybe I can present the model on Saturday this week. Stay tuned, it will look awesome! 

The London aurochs skull

My aurochs bull model is finally finished, but before I have the opportunity to take good photos of it, I want to cover an interesting aurochs specimen for today which is one of the individuals that I used as a reference for my model: the London skull. 

The London skull is a very impressive specimen. It was found in Ilford, London, is from the Neolithic period and on display in the Museum of London. Its sheer size of 91,2cm* from the top of the skull to the tip of the nasal bone as well as its morphology indicates that was a massive, large and fully mature bull. The horns are very thick, especially at the base, and proportionally large. The eye sockets are very prominent and the skull is robust in build overall. It is the largest  and most massive complete aurochs skull that I have seen so far and its length is the largest recorded in the literature (Frisch, 2010). The London bull might have been one of the 190cm tall beasts of the early Holocene. 

* This is very, very large, even for an aurochs bull. The average of aurochs skull lengths is 60-70cm according to the literature, and I found a photo on the web with a scale bar that might indicate the skull is “only” 60 cm long. 

A photo of the skull in profile view that I found on the internet shows that the horns have an angle of  about 70% relative to the snout and the snout has a slightly convex profile. Since the end of the nasal bone is turned down a little bit, I think it might be possible that the snout might be a bit down-turned and round like we see it in some Lidia today (another example how Lidia preserves some of the original aurochs traits and their variation). 

Too bad only the skull of this specimen is known or at least only on display. It must have been a very, very spectacular individual in life. And my model that just has been finished will give you a lively impression for that, stay tuned.