From prehistoric to historic cattle - preview of article for DCS Bulletin

[Louisa Gidney]

I've put together this article in response to several recent discussions on this forum. I'm about to submit it to the Bulletin but it will be months before it appears in that, so I though I'd post it here first to keep the conversational ball rolling.


From Prehistoric to Historic Cattle – a reply to Beryl Rutherford.

Beryl’s article in the Summer 2008 Bulletin was an interesting read but, unfortunately, promulgated some very outdated views. As the DCS’ resident archaeologist, I thought it might help to summarise some current thinking.
To begin with, Prehistoric can be broken down into something less amorphous than everything prior to Julius Caesar’s invasion. Until roughly 10,000BC, Europe was in the grip of a succession of glacial periods, or the Ice Age. Britain was largely covered with ice. People used stone tools, generically known as Palaeolithic. The wild cattle were Bos primigenius or the Aurochs, which were very large animals, roughly 1.9m withers height. The ice then melted and plants, animals and people colonised the land exposed by the retreating ice sheets. Sea levels rose with the addition of the meltwater so some species, for example the aurochs, failed to reach places like Ireland before the land bridge was submerged. The people living in Britain were hunters and gatherers, still using stone tools, known as Mesolithic. Aurochs were certainly hunted, with bones recovered from the famous site of Star Carr in the Vale of Pickering. About 4000BC there was a profound change to a farming lifestyle, still using stone tools, known as Neolithic, but also using pottery. These farmers had domestic livestock that must have been introduced to Britain from Europe in boats, as the English channel had flooded. Sheep and goats are not native to northern Europe so are unequivocal imports. The early domestic cattle not much smaller than the wild aurochs, so it was unclear whether cattle had been brought in or were domesticated locally from wild aurochs. Recent advances in DNA profiling clearly show that the Neolithic domestic cattle differ from the aurochs found in Britain, so the farmers had brought their cattle with them and did not cross breed with the wild cattle. Some 2000 years later, by the end of the Neolithic and start of the Bronze Age, the domestic cattle had further reduced in size. Some of this reduction in size could be due to the presence of a form of dwarfism in Neolithic cattle. A calf humerus from a Neolithic site at the Knap of Howar in the Orkneys clearly exhibits dyschondroplasia.
It used to be thought that the Neolithic farmers only used their cattle for beef and that draught oxen and dairy cattle were part of a “Secondary Products Revolution” associated with the later Bronze Age. An exciting range of research projects utilising innovative scientific techniques, including analysing food residues in pottery, are demonstrating that Neolithic farmers were milking their cattle and making a range of dairy products.
Technology advanced with the advent of metallurgy based on copper alloys, hence the name Bronze Age for the period spanning roughly 2000-700BC. During this period the British aurochs became extinct, probably because of humans destroying the preferred habitat of the aurochs rather than hunting them. Only 25 years ago, a conference paper proposing cattle dairying at the Bronze Age site of Grimes Graves, based on the age profile of the cattle bones with elderly females and infant calves, provoked heated debate and outright denial. Nowadays the controversial has become mainstream thinking.
Several points stand out here as pertinent to the Dexter. Humans deliberately bred smaller cattle in antagonism to the default size of both the wild ancestor, the aurochs, and the earliest domestic cattle. The small cattle included examples with a genetic dwarfism. Humans have been actively selecting for dairy production, in association with small size, for several thousand years.
The Iron Age (no prizes for guessing why so named!) commenced roughly 700BC in Britain and ended with the Roman invasion of 43AD. Iron Age archaeological sites are far more abundant than those of the more remote past, with certain hillforts still dominating modern landscapes. The Butser Ancient Farm project was designed to quantify the productivity of Iron Age arable farming, with the livestock being a secondary academic consideration but invaluable for public appeal and “cute factor”. Peter Jewell, a respected zooarchaeologist and later a founding member of RBST, was asked to advise on appropriate breeds. The Dexter was suggested as the only modern breed then available that approximated to the archaeological finds of cattle bones. Peter Jewell made it very clear at the time that small Kerry cattle would have been a better option but the parlous state of all rare breed cattle in the 1960’s meant that this was not possible. The Kerry had become too tall and the Dexter, though a better size, was too chunky in build.
Roman forts in northern England produce cattle bones in abundance, in comparison to the native Romano-British farmsteads which are generally sited on soils where animal bone does not survive. The graph below shows the range of withers heights estimated from the cattle metapodials, or cannon bones, from Vindolanda in the mid-section of the hinterland of Hadrian’s Wall and South Shields on the coast as the eastern defence. Both populations show a normal bell curve distribution with sufficient overlap to suggest no major difference in population between the two groups. However the range is important with examples both of the very tiny animals, that are affectionately referred to as “cow kittens” by some Dexter breeders, and very large animals at the other extreme. It cannot be emphasised too strongly that such a range is “normal” in biological terminology, irrespective of whether the very small animals may, or may not, be carriers of dwarfism. The fact that the shortest animals from South Shields fall below 0.98m, which is 2 Standard Deviations from the mean of 1.12m, could suggest the possibility of a form of dwarfism being present. What is clear is that this extremely small type, though present, was not being actively selected for, in contrast to the modern Dexter. This graph demonstrates one possible outcome of a strategy that has been suggested to reduce the incidence of achondroplasia in the modern Dexter, by eliminating the use of carrier bulls. Two possible carrier cows might be represented in a sample of 76 bones from South Shields. No unviable calves would be produced and the presence of carrier cows would continue at the same negligible incidence

Over the past 200 years, livestock breeders have interfered with the biologically normal range by endeavouring to breed animals that fit within a reduced range of height variation. In the Dexter this has been towards the smaller end of the range, but the same foundation population could equally have been bred towards the larger end of the range. In effect, this is how evolution works but the process is considerably speeded up by controlled breeding. The concept of a “level herd” is, in archaeological terms, a very modern concept.

The photograph above of the Doesmead herd in 1966, from Ted Neal’s book, is a very important image, showing a herd where selection for dairy production appears to have been considerably more important than looks. There is an interesting range of small and large, chunky and slender animals. This picture gives an idea of what the archaeological cattle represented in the graph could have looked like. The Doesmead herd further emphasises that selection in the Dexter for herds where all the animals are more or less the same size is a very recent phenomenon. It is therefore not surprising that, irrespective of the presence or absence of the dwarf gene, the modern Dexter should still exhibit a range of sizes both between herds and within herds, such as my own, where parameters other than height are seen as more important for selection and retention of breeding stock.

[Louisa Gidney]

Bother, the graph & piccie didn't come out. But at least you should get the idea. Perhaps some technological whizz kid could help out?

[Broomcroft]

If you email me what you've got Louisa, I'll have a go at posting it unless you've already got it organised. clive@broomcroft.com

[Broomcroft]

Louisa

I understand that Heck cattle were bred to get back to what Bos primigenius was supposed to be like. Do you think that these cattle are anything like what was really roaming around back then?



Here's a link to Wikipedia for anyone interested:
http://en.wikipedia.org/wiki/Heck_cattle

[Louisa Gidney]

The Heck cattle give an impression of the aurochs but are by no means an accurate phenotype yet. There's a very good book on on the whole topic: Aurochs by Cis van Vuure, very readable. No-one has yet, that I'm aware of, done any osteology of the Heck cattle.

[Woodmagic]

As recently as last year Beverley McCulloch the historian, having spent time investigating the Dexter stated they were venerated in Ireland from as early as the Neolithic ‘Stone Age’. He quotes from the Book of Kells, dating from around AD 800; and also refers to the book of the Dun Cow’ – which was treated as a holy relic because the vellum on which it was written was said to be made from the hide of a pet, dun-coloured cow which belonged to St Ciaran, who lived around AD 512 to AD 545.
We are all aware of many scientific claims being overturned later; I would refer you to ‘ Survival of the Fittest’ by Sue Baker. I have never felt the Dexter was very closely related to our other cattle, anyone who has experience of Exmoor ponies and Dexters will agree that they are very similar in behaviour, and I believe they have a similar history (before someone tries to correct me, I am not suggesting they are related!), but neither am I convinced that Dexters are descended from the Aurochs.
I am too long in the tooth to delve into fundamental Dexter history, but I hope somebody will one day. The chondro condition can arise through a spontaneous mutation, most human dwarves occur in this fashion,
but the Dexter could not have survived if the achondrodysplasia had been endemic. My own experience using only a chondro bull and retaining all the progeny was that the herd was gradually becoming predominantly long leg, although the bias should have been the reverse.
You refer Louise to two ‘possible carriers’, if Dr Harpden is correct – Congress 98 - it should be possible to identify by the bone construction. It cannot be identified by size; many of my animals are the same size or smaller than many dwarves. Breeding the medium type eliminates vast differences in size; the animal automatically becomes uniform. When breeding to the dwarf the size of the parent cannot be identified and only becomes apparent when the calf inherits two working genes. ,
When I first came into the breed the medium non-chondro were common, but the breeder was consistently breeding for the lethal, and the ‘medium leg’ were fast being bred out, until I started selecting for them while discarding the dwarf. I didn’t manufacture the medium, they are integral to the Dexter while the carrier is the same animal minus one important gene, and cannot survive unless it retains one of the pair of working genes. I believe the big cattle are a throwback to the cross, almost certainly Devon, which was used in the eighteenth century to improve the beef potential. The size runs in families and not haphazardly in my experience. Incidentally, it seems possible that the Devon and Dexter share a common ancestor; the Devon can be taken back to Roman times.
Hardly surprising that today’s Dexter is ‘more chunky’ in view of the poor winter feed then available, but he may have been looking at the dwarf and I doubt there is much difference between the modern medium leg and its ancient ancestors.

Beryl (Woodmagic)

[Woodmagic]

Correction, I should have checked instead of relying on my memory!
My apologies to Dr Harper for mis-spelling his name. In any case the attribution should have been to Dr Williams - page 57 'Proceedings of the World Congress'. He refers to the bulldog calf and I would have thought that the heterozygote would have shown some indication.
Beryl (Woodmagic)

[Broomcroft]

Here is the photo and graph that Louisa was referring to in her original post above:

[Woodmagic]

Mr Tuckey used only short leg bulls, but retained both types of cow, he selected on the basis of yield, and asserted that the Dexter was a pure dairy breed, and unsuitable for beef.
Beryl (Woodmagic)

[Broomcroft]

Just as a side-note.......the caption says that's the A38......and they call that a traffic jam :D.

[Pennielea]

What a selection of sizes and horn patterns. I can see why Mr Tucker considered them a pure dairy breed!

Ian

[Louisa Gidney]

Many thanks to Clive for getting the piccies posted up for me. Yes, the sizes and horn shapes of the Doesmead herd do show a wonderful variety but this is my whole point. This is exactly what a herd of "unimproved" or archaeological cattle should and did look like IF you are selecting for a production parameter, such as milk yield, rather than a visual parameter, such as height, or a level herd. This is why Clive keeps saying that his sheep with the highest EBV is a plain looking animal, not "Showy".
This also ties in to the whole "Ungulate Paradox", which I don't have to hand but in essence states that the "best" animals, in terms of body condition and fecundity, have the shortest life expectancy. So, if longevity is an important parameter for selection, this will encourage the retention of "plain" animals as these have better survivability. Those who are RBST members will have seen an article on Soay sheep on Hirta in a recent issue of The Ark, which shows how this works in a real life situation under natural selection.

[Woodmagic]

In the days of horns we recognised Dexter horns and Kerry horns, mine even today, when they are allowed to grow, are uniform and Dexter, but the longevity is excellent, and the animals are very uniform. I have in the last two or three years had two animals live and breed to 20 plus when I had them put down. I would describe the Doesmead as having a mix of Dexter and Kerry horns. The Doesmead that I bought in took several generations to gain much beef, although they milked well.

[Woodmagic]

In the days of horns we recognised Dexter horns and Kerry horns, mine even today, when they are allowed to grow, are uniform and Dexter, but the longevity is excellent, and the animals are very uniform. I have in the last two or three years had two animals live and breed to 20 plus when I had them put down. I would describe the Doesmead as having a mix of Dexter and Kerry horns. The Doesmead that I bought in took several generations to gain much beef, although they milked well.
Beryl (Woodmagic)

[Broomcroft]

How many Dexter milking herds were there in the UK or in Devon Beryl? Just you and Mr Tuckey or were there more?