Is it possible to keep dairy cows and their calves together in automatic milking systems? What are the effects on milk yield, calf growth, health and fertility?
In an on-going research project at SLU in Uppsala some cows in the dairy herd at the The Swedish Livestock Research Centre are kept together with their calves in the beginning of the lactation. The aim of the project is to test if calves can be integrated in automatic milking systems (AMS). There is interest from farmers and consumers in keeping dairy calves with their dams but there is very little support from science on how to go about it.
Photo: Jenny Svennås-Gillner, SLU
Some research projects have already been carried out in this field, for example the doctoral thesis by Sofie Fröberg, but many research questions still need an answer. One example is the fact that many cows that nurse their calf seem to not eject milk as well to the milking machine as other cows do. This means that the loss of milk in the tank exceeds what the calf consumes. However, in the studies that have been published the management of the cows the very first days of lactation is not described in detail. We think that there are possibilities to enable milk ejection to both calf and milking machine and that the management routines the first days of the lactation may be important in this.
The robotic milking is a key factor for the combination of suckling and milking, since robots milk each udder quarter separately. It is common that calves prefer front teats and they can therefore be empty at the time of milking, while the hind quarters are full of milk.
Cows of the Swedish Red and Swedish Holstein in the SLU dairy herd in Uppsala are included in the project. The first batch of cows calved from the middle of August until the middle of September 2019 and they were kept with their calves until Christmas. In addition, twelve control cows, managed according to the standard routines in the herd, were included. The experimental cows calved outside in single pens in a mobile shed that houses four calving pens. All calvings went well, all cows had satisfactory colostrum quality and all calves suckled colostrum from their dam. Cow and calf were kept in the calving pen for the first 2-3 days post partum. The cow was fetched from the calving pen daily, to be milked in the VMS-unit. After the first few days the CowCalf pair were introduced to the group. Six CowCalf pairs moved into the VMS, and made up the "indoor group" and the remaining six pairs stayed outside until the frost came, these are referred to as the "outdoor group".
Mobile shed from Playmek (www.playmek.se/mobilt-vindskydd). Photo: Mia Jernhake, SLU.
The indoor group had a contact area where the calves stayed at all times. Cows could access this area and in addition to meeting the calf they had access to cubicles, concentrate feeders and water in the contact area. When they wanted to eat roughage, use the comfort brush or be milked they left the contact area through a passive selection gate, which cows but not calves can open. On the way back to the calves the cows pass a selection gate that either let them straight back to the calves or directed her to milking. After passing through the milking unit she can go to the selection gate again and was then directed to the contact area. In the far end of the contact area there was a calf creep, which is an area that calves but not cows have access to. In the creep calves had cubicles and were offered hay and concentrate. There was also a scale there, for weekly body weight registrations.
Photo: Jenny Svennås-Gillner, SLU
The contact area for the outdoor group was a pasture pen. The mobile shed used for the calvings now worked as a shelter from wind, rain and sun for cows and calves. One part of the shelter made up part of the outdoor calf creep, where calves had access to water, hay and concentrate and it was also equipped with a scale for weighing the calves. The cows could leave the contact area through a one-way selection gate (same as in the indoor set-up). Cows had access to water just outside this gate, to stimulate them to pass the gate. Once they passed the gate it seems to be easy for them to decide to go to the VMS unit, where they have access to comfort brushes, the milking unit, roughage, concentrate and other cows. Apart from the obvious difference between being indoor or outdoor the groups differ in that cows and calves outdoor can eat grass together. Research has shown that the interest in new feeds is stronger throughout life in individuals who were able to eat together with older animals in beginning of life.
Outdoor contact area. Photo: Sigrid Agenäs, SLU.
GEA FeedSelect one-way gate that allows cows but not calves to go pass. Foto Mia Jernhake, SLU
Several solutions for how to manage the cows and calves together have already been tested in this project, trying to find a solution that works well for animals and staff. It is important that cows are milked regularly and this is affected by how different resources are made available for the cows. Initially there was a large variation between cows in the frequency of visits to the milking unit. Some went several times per 24-hours while others did not go at all or did not release milk to the milking machine. When all cows had passed the first two weeks of lactation they visited the milking unit twice a day or more often. In lactation week two they gave 10-24 kg milk to the milking machine per day. It is less than the cows in the control group gave in lactation week two but this is not surprising since the cows also provide milk for their calf. The calves grew around 1.3 kg/day compared to 0.9 kg/day in the control calves.
The project is carried out in very close collaboration between the researchers and the barn staff. The staff have the daily supervision of the animals and notice if anything in the layout needs to be adjusted. Particular emphasis is put on handling the animals as calmly and gently as possible and to give them the chance to work things out by themselves. Time, patience and routines have been identified as important factors to make the system work. Before calving all cows in the first batch were trained daily to leave the outdoor calving area, go through the selection gate, to the VMS and through the milking unit. This was done for a couple of weeks before calvings started and the time needed for them to find the way to the milking unit decreased very quickly.
Indoor contact area. Photo: Sigrid Agenäs, SLU
In early lactation the cows had access to the calves day and night. When the calves were around eight weeks old the contact was restricted to half day, as a first step of the coming weaning and separation. During the half day contact period cows and calves could see each other and they were able to make contact but suckling was not possible. At around four months of age the calve and cows were moved out of the unit, to separate units. At this time calves weighed close to 200 kg and had started to show signs of puberty.
A second batch of 22 CowCalf pairs (and 18 control cows) were inserted in March and April 2020. They were housed indoors at first, in a system similar to the first batch but the contact area and calf creep were put in a different location in the AMS unit. In mid May they were turned out to pasture. When calves were 14 to 20 weeks old they were separated from the cows by a fence line. Two weeks prior to the fence line separation calves were weaned by a nose flap that prevented them from suckling. A third batch of 20 CowCalf pairs, 20 control cows and 20 control calves will be recruited starting with calvings 1st of September 2020. This will be a pure indoor batch and the indoor system will be very similar to that used in the second batch.
The project will run for at least three years. Effects on total milk yield in the lactation, health, behavior and fertility by caring for the calf in early lactation will be evaluated in the cows. Heifer calves born in the project will be followed until their own first lactation, to allow evaluation of long term effects on growth, health, behavior, fertility and indicators for possible longevity. There is also an aim for the project to present a working system for integrating calves in systems for automatic milking.
Sigrid Agenäs, SLU
Hanna Eriksson, SLU
Daiana De Oliveira, SLU
Carlos Hernandez, SLU
Kjell Holtenius, SLU
Anders Herrlin, SLU
Emma Ternman, SLU
Sabine Ferneborg, NMBU, Norway
Rupert Bruckmaier, Vetsuisse Faculty, Switzerland
Peter Krawczel, University of Helsinki, Finland
The project group has close collaboration with other research groups in Europe and America who are studying different systems for managing dairy calves, including possibilities to keep them together with their dams.
The project is funded by the Swedish research council Formas and the foundation Seydlitz MP bolagen.
The project is managed by Professor Sigrid Agenäs and Post-Doc Hanna Eriksson at the Department of Animal Nutrition and Management and Daiana de Oliveira who is a researcher at the Department of Animal Environment and Health. There are another seven researchers in the project group and a reference group including representatives appointed by the federation of Swedish farmers (LRF) and the extension service company Växa Sverige will also follow the project.