That fertility diminishes is a well known problem in animal husbandry. As the cow produces more milk, her opportunities to become pregnant diminish. Because of weak periods on heat, it is necessary to make several inseminations, which increases the costs of the farmer.
In order that it should not be necessary to treat cows with hormones as in the US, researcher at SLU are hoping to find a method to stimulate and also detect oestrus by other means. A vision in future is that insects (hymenoptera) may be trained to mark the scent from cows in heat!
Pheromones on the nose
Veterinary surgeon Kristina Nordéus is a postgraduate student engaged in the project that is conducted at SLU in Uppsala. Just now she is engaged in an intensive phase of her research. Every twelve hours she must change the substances containing pheromones in a plastic sleeve attached to the nose ring of every heifer. These substances are urine and mucus from cows at the height of their oestrous cycle. She will observe ten heifers during four oestrous cycles and register how the hormones are influenced.
Medicine and entomology
The project involves research at fundamental level; it concerns, inter alia, identification of which, if any, pheromones stimulate and influence the oestrous cycle in cows. To be able to do this, veterinary surgeons at Division of Reproduction at SLU Uppsala are collaborating with entomological researchers at SLU in Alnarp.
Insects as detectors
For the individual farmer it would be of great benefit if the oestrous cycles of cows coincided in time. Kristina hopes that this will be possible in future through stimulation with pheromones. But it is also necessary to detect when the cow is in heat. The hope centres on the capacity of insects to detect scents.
In the US, hymenoptera have been successfully trained to recognise scents from drugs and explosives. A box of insects that have been trained to mark the scent of oestrus would be a fantastic aid in work on the farm.