Monday, March 30, 2009

Archaeologists Find Earliest Known Domestic Horses: Harnessed and Milked

ScienceDaily (Mar. 8, 2009) — An international team of archaeologists has uncovered the earliest known evidence of horses being domesticated by humans. The discovery suggests that horses were both ridden and milked. The findings could point to the very beginnings of horse domestication and the origins of the horse breeds we know today. Led by the Universities of Exeter and Bristol (UK), the research is published on Friday 6 March 2009 in journal Science.


The researchers have traced the origins of horse domestication back to the Botai Culture of Kazakhstan circa 5,500 years ago. This is about 1,000 years earlier than thought and about 2,000 years earlier than domestic horses are known to have been in Europe. Their findings strongly suggest that horses were originally domesticated, not just for riding, but also to provide food, including milk.

Through extensive archaeological fieldwork and subsequent analysis, using new techniques, the team developed three independent lines of evidence for early horse domestication. Their findings show that in the fourth millennium BC horses in Kazakhstan were being selectively bred for domestic use. They also show horses were being harnessed, possibly for riding, and that people were consuming horse milk.

Analysis of ancient bone remains showed that the horses were similar in shape to Bronze Age domestic horses and different from wild horses from the same region. This suggests that people were selecting wild horses for their physical attributes, which were then exaggerated through breeding.

The team used a new technique to search for 'bit damage' caused by horses being harnessed or bridled. The results showed that horses had indeed been harnessed, suggesting they could have been ridden.

Using a novel method of lipid residue analysis, the researchers also analysed Botai pottery and found traces of fats from horse milk. Mare's milk is still drunk in Kazakhstan, a country in which horse traditions run deep, and is usually fermented into a slightly alcoholic drink called 'koumiss'. While it was known that koumiss had been produced for centuries, this study shows the practice dates back to the very earliest horse herders.

Lead author Dr Alan Outram of the University of Exeter said: "The domestication of horses is known to have had immense social and economic significance, advancing communications, transport, food production and warfare. Our findings indicate that horses were being domesticated about 1,000 years earlier than previously thought. This is significant because it changes our understanding of how these early societies developed."

The steppe zones, east of the Ural Mountains in Northern Kazakhstan, are known to have been a prime habitat for wild horses thousands of years ago. They were a commonly hunted animal. This may have set the stage for horse domestication by providing indigenous cultures with access to plentiful wild herds and the opportunity to gain an intimate knowledge of equine behaviour. Horses appear to have been domesticated in preference to adopting a herding economy based upon domestic cattle, sheep and goats. Horses have the advantage of being adapted to severe winters and they are able to graze year round, even through snow. Cattle, sheep and goats need to be to be provided with winter fodder, and were a later addition to the prehistoric economies of the region.

This study was carried out by the Universities of Exeter, Bristol and Winchester (UK), Carnegie Museum of Natural History (Pittsburgh, USA), and Kokshetau University (Kazakhstan) and was supported by the Natural Environment Research Council, British Academy and National Science Foundation of America.


Journal reference:

  1. Outram et al. The Earliest Horse Harnessing and Milking. Science, 2009; 323 (5919):

In Horse Play, Adult-to-young Ratio Is Key

ScienceDaily (Mar. 24, 2009) — Adults of many animal species play a crucial role in the social development of youngsters. A new study reveals that the ratio of adults to young plays a much more important role in social development than the mere presence of adults.


Marie Bourjade, Alice de Boyer des Roches and Martine Hausberger of the University of Rennes 1, France, studied the effects of the adult-young ratios in naturally-formed groups of Przewalski horses on aggression rates and social cohesion of young horses. Previous studies led by the laboratory have shown that this ratio plays an essential role in song acquisition in songbirds (which has parallels with human language development) and so the authors sought to find a more general principle regarding the effects of adult-young ratios on social behaviour.

Bourjade and colleagues explained, "Przewalski horses constitute a very adequate model for investigating the educational roles of experienced adults as the species forms year-round stable groups with both maternal and paternal carers as well as the presence of unrelated adult females."

The results revealed striking differences, depending on the adult-young ratios. "When in a group in which adult-young ratios were low, young horses were more aggressive and more segregated from adults and they established tighter bonds with other young," the scientists remarked. "Tighter bonds between young in groups with low proportions of adults could be a factor which decreases the attention paid to adults and probably reduces their influence as regulators of the behaviour of young, in particular their aggressive behaviour."

Beyond fundamental questions raised by these findings about modalities of the influence of adults on the development of youngsters, the authors argue that, "adult-young ratios appear to be an important feature of social settings that must be taken into account as a potential modulator of social influence when evaluating developmental processes."

Selective attention towards social partners may enhance or inhibit the influence of adults. This study, which builds upon previous results regarding vocal development, suggests there is basis for a very general phenomenon with important implications for the social settings of captive and domestic animals. It may even lead us to question the best social environment for childcare and education.


Journal reference:

  1. Giurfa et al. Adult-Young Ratio, a Major Factor Regulating Social Behaviour of Young: A Horse Study. PLoS ONE, 2009; 4 (3): e4888 DOI:

Sweets Make Young Horses Harder To Train, Study Finds

ScienceDaily (Aug. 19, 2008) — Young horses may be easier to train if they temporarily lay off the sweets, says a Montana State University study where two-year-olds wore pedometers, wrist watches and Ace bandages.


A commercial mixture of corn, oats, barley and molasses -- sometimes called "sweet grain" or "sweet feed" -- gives horses the glossy coat and lively spirit that makes them attractive to prospective buyers, said Jan Bowman, an animal nutritionist at MSU.

But the extra energy provided by sweet grain during the early stages of training made the horses in MSU's study more disobedient and fearful than horses that only ate hay, Bowman said. The grain-eaters spent more time resisting the saddle. They startled easier. They bucked and ran more during training.

Early training, which usually lasts about 30 days, gives young horses the foundation they need for more advanced training, Bowman said. They learn to move sideways on command, for example. They learn how to move their front or hind feet in any direction.

"Results suggest that trainers under time constraints could increase their training effectiveness during the early stages of training by not feeding excess dietary energy," Wade Black wrote in a paper that will be submitted later this year to the "Journal of Animal Science."

Black -- a horse trainer, instructor for the MSU Colt Starting class and one of Bowman's graduate students -- came up with the idea for the study when he was an undergraduate in her equine nutrition class, Bowman said. She and Black then conducted experiments during the summer of 2007. Black presented their findings to the American Society of Animal Science in June this year. He is still analyzing some of the data to see how the grain affected the horses' adrenaline during training.

The study involved 12 closely-related quarter horses that came from one Idaho ranch, Bowman said. Black trained the horses for three weeks, five days a week at MSU's Miller Livestock Pavilion. Half the horses ate only hay. The hay was a mixture of grass and alfalfa. The other horses ate five pounds of sweet grain a day in addition to the hay. Both groups ate as much hay and drank as much water as they wanted.

Each horse wore a pedometer adjusted to its stride and attached with an Ace bandage to its left front leg above the knee, Bowman said. Each horse also had a combination wristwatch-heart monitor hanging from its saddle. The watch displayed minimum, maximum and mean heart rates detected by an electrode belt.

Black trained the animals for 30 or 40 minutes a day without knowing which animal had eaten grain and which one hadn't, Bowman said. She and Black then recorded heart rates and the number of steps the horses took during training. They scored behaviors like obedience, get-up-and-go and separation anxiety.

Horses that ate both grain and hay became more upset when they were separated from the herd, Bowman said. They whinnied more and were livelier and less submissive than the horses that ate only hay.

The study doesn't mean that trainers should keep grain away from horses forever, Bowman said. They might consider withholding it just during the early weeks of training.

"We don't want to give the impression that you should starve them in order to enhance their good behavior," Bowman said. "That's not the point of it."

Wade wrote in his paper that, "Horses, being ridden by less experienced riders, need to be calm and easy to handle, characteristics that may be enhanced by more effective early training."

Bowman noted that all of the horses in MSU's study gained weight during the study. It didn't matter if they ate hay alone or hay with grain.


Sunday, March 29, 2009