SLU news

Automatic weighing of grazing cattle to detect parasite infestations

Published: 05 September 2018
Photo:Calves on pasture going in to a scale.

Weighing of animals can be a good method to detect parasitic infestations at early stages, but it is laborious and extra difficult if the animals are on pasture, where the risk of parasites also is highest. By developing an automatic and solar-powered weighing station, a group of researchers wanted to see if it could monitor the weight of animals, even in small and remote pastures.

Parasitic infestations can lead to poorer animal welfare, economic losses and lower efficiency in animal production. In conventional animal herds prophylactically treatments are used in regular intervals, which is effective, but it can also lead to increased resistance of the parasites. In organic production, it is not allowed to treat groups of animal preventionally, instead, the animals should be treated selectively where only affected animals are dewormed. Regular weight control is a method for detecting parasite-infested individuals, but it is time-consuming and laborious, especially if the animals are on pasture.

Automatic weighing is developed for stables, but how do you monitor the weight of animals out on pasture? In this trial automatic weighing stations were mounted at the exit from a small fold in the pasture where the water cups were placed. The animals entered the fold through a self-opened one-way gate but had to pass the weighing-machine on their way out. The animals were divided into two groups where half were infected with Ostertagia ostertagi and Cooperia oncophora, while the other group was treated with anthelmintics. The researchers also wanted to see if there was a difference in resistability between purebred dairy calves and dairy-beef crossbreeds.

The experiment shows that there is a great potential for using solar-powered fully automatic weighing as a way to monitor cattle on pasture, measure growth in weighing stations, and early detection of animals that deviate. The technology needs further development so that it can be used in practice for better animal health and less drug use.

As expected, the dewormed animals grew better than the animals suffering from a parasitic infestation. During installation, the dewormed crossbreed animals weighed 37 kg more than those infected with parasites. For the dairy breed animals, the same difference was 17 kg.