Cattle - for sustainable food security in times of water scarcity

In recent years, low groundwater levels, lack of drinking water and droughts have been a problem in Sweden in areas with high dairy production and cows. Cows are ruminants and there are studies on other ruminants (e.g. goats) suggesting that they can adapt kidney function and skin evaporation to better manage water. They can excrete a highly concentrated urine (i.e. urine with a lot of residual and excess products and little water) without affecting their milk production and welfare. Due to the characteristics of their kidneys, they can also drink salt water up to a certain salinity. Ruminants can also drink a lot at one time and store the water in their stomachs to be used for a longer period of time when drinking water is not available. These abilities vary between different species of ruminants and also between different breeds within a species. For example, Somali goats are better at it than the Swedish landrace goat.

The aim of this project is to investigate whether it is possible to significantly reduce the need for groundwater as drinking water for Swedish cows by changing watering practices, and perhaps the choice of cow breed. There are studies that suggest that time-regulated access to water and access to brackish water only does not necessarily have a negative effect on either milk production or animal welfare in cows. However, there are some shortcomings in these studies that make it unclear whether the results are due to the treatments or to the different groups of cows studied. In addition, no studies have been conducted under Swedish conditions. Southern Sweden, with Öland and Gotland, is particularly interesting because the groundwater problem has been great there. We want to use controlled studies to investigate whether different watering intervals can make Swedish cows economise on water and whether they can drink brackish water equivalent to that found in the southern Baltic Sea. In our studies on dairy cows, different ways of watering will be evaluated on the same cows, which will allow us to draw conclusions about the cows' ability to adapt. Our hypothesis is that also Swedish cows, and especially the red-white breed, can economise heavily on groundwater and even do without, drinking only brackish water. Our specific hypothesis is that if any of our proposed practices are implemented, the need for groundwater for dairy cows can be reduced by at least 30%, perhaps by 100%, without jeopardising production and animal welfare.

We want to study both dairy cows and cows grazing along the Baltic coast. We will study the microbial quality of the Baltic Sea water that the cows drink. We will look for harmful microorganisms and also investigate whether the water intake affects the cows' gut flora and the incidence of diarrhoea.

If the project shows that the strategies we propose are well-functioning, it opens up, not only for efficient water utilisation, but also for the re-establishment of natural grazing areas along the Baltic Sea that are currently not used due to difficulties in obtaining drinking water. This will benefit both biodiversity and increase Sweden's ability to produce food in a sustainable way.

The overall aim of the project is to develop new knowledge so that Swedish water resources can be used efficiently and to help Swedish farmers find solutions if groundwater availability becomes limited. This type of knowledge could be invaluable for the future of Swedish dairy farming and, as mentioned, could also contribute to increased use of natural pastures that hold an important part of biodiversity. The project can thus affect the sustainability of the entire dairy and dairy cow system.

The project is funded by Formas and includes researchers from SLU, Rise and Växa. LRF and a county administrative board are also involved as discussion partners. Lea Managos is a PhD student in the project.