Bovaer effectively reduces cows' methane emissions. To reduce methane emissions from conventional dairy cows, Danish farmers can choose one of two measures starting this year: Either the animals must be fed additional fat all year or the feed additive Bovaer for a period of time.

Previous studies at Department of Animal and Veterinary Sciences, Aarhus University have shown a reduction in feed intake when Bovaer was added to the cows’ feed. The reason for this is unknown, but a reduced feed intake can be a sign that the welfare of the animal is affected.

What does Bovaer mean for cow welfare?

During the project, the researchers will follow the cows’ activities, lying behavior, social behavior, and comfort behavior. Meanwhile the cows' feed intake and feeding behaviour will also be measured using automatic feed bins.

The researchers will also investigate whether dairy cows will avoid feed with added Bovaer if given the choice. This is done by giving the cow the option to eat feed with and without the additive.

Cows are able to avoid feed additive that make them feel uncomfortable, by associating this discomfort this with feed characteristics, such as taste or location. This behaviour can be used in behavioural tests to investigate whether cows will avoid certain feedstuffs or additives, or certain concentrations of them.

First of its kind

Up until now, studies of the effects of Bovaer have focused on the additive's effect on the animals' methane emissions and performance.

This project is the first to investigate whether Bovaer affects animal welfare. Studies done at Aarhus University have shown a reduction in feed intake, while other studies show no change.

 “Reduced appetite and feed intake can be caused by several factors, and it can be a sign of discomfort. Therefore, there is reason to investigate whether Bovaer has a negative impact on animal welfare,” says project leader Professor Margit Bak Jensen.

 “Other signs of discomfort are reduced activity, reduced self-grooming and reduces social behaviour. We do not know if the reduced intake, which has been seen in previous studies in cows fed Bovaer is associated with similar changes in behaviour, but that is one of the things we will look into in this project,” she says.

The project is funded by the Danish Ministry of Food, Agriculture and Fisheries and includes both lactating cows and dry cows.