Rein tension, something horses get used to?

During the ISES Conference an danish/ukrainian team had examined how much rein tension a horse was ready to accept in order to obtain food reward. The horses in the study was 2 years old and not experienced to bridles before.

At the test the horses had reins attached by the bit to a girth and the length of the reins created the resistance which the horses experienced when they stretched to reach the food. The researchers assumed that the first time the horses were subjected to tests, they would put a little pressure on the bit, but when they had realized that there were titbits involved they would be willing to increase the pressure of the bit to access the food.

The results showed otherwise. The horses applied the highest rein tension on the first day 10,5N +/- 1,4N (10 Newton or approx 1 kg) but for the following sessions they avoided to put so much pressure into the bit (6,0N and 5,7N). Instead of getting used to the pressure (habituated) the horses learned to avoid the pressure in the mouth. It was concluded that horses ability to avoid tension could be used in horse training by increasing focus on the timing of pressure release.

Of course I make (fully unscientifical) connections to the controversial training method roll kür and LDR varieties. Bone-wise the bars are razor sharp ridges that are covered with a very thin layer for protection. The bit is placed on these ridges. A high pressure on the bit creates such discomfort that the horse just "takes the pressure once" and then make whatever it can to avoid the discomfort in the future.

For me, it may be a way to understand how an animal that is so much stronger than us can keep itself from breaking free from the position that roll kür and LDR puts them in. They "curl themselves up" in a (desperate?) attempt to avoid the discomfort that pressure from the hands, through the reins and bit create on the bars.

During the conference suggestions were made to introduce so-called pressure gauges on the reins during dressage competitions. But I think it's too late to measure the pressure at that point. It must be done during training. Because if the horse seeks to avoid the pressure it will have learned to take the position itself that creates the least discomfort and that without the rider necessarily putting much pressure in the reins.

The focus must shift from what we can see on the competition grounds to what we can not see during training. Ethics will have to range from training to competition and, as another scientist said, "even if it is not illegal, it need not be ethically correct".