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
Experiences from previous research suggest that cows that are kept with their calf are less likely to eject milk to the milking machine. If this is true, 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 are kept with their calves now. In addition, twelve control cows, managed according to the standard routines in the herd, are recruited. 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, they make up the "indoor group" and the remaining six pairs are the "outdoor group".
Mobile shed from Playmek (www.playmek.se/mobilt-vindskydd). Photo: Mia Jernhake, SLU.
The indoor group have a contact area where the calves stay at all times. Cows can access this area and in addition to meeting the calf they have access to cubicles, concentrate feeders and water in the contact area. When they want to eat roughage, use the comfort brush or be milked they leave 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 her straight back to the calf or directs her to milking. After passing through the milking unit she can go to the selection gate again and will then be directed to the contact area. In the far end of the contact area there is a calf creep, which is an area that calves but not cows have access to. In the creep calves have cubicles and are offered hay and concentrate. There is also a scale there, for weekly body weight registrations.
Photo: Jenny Svennås-Gillner, SLU
The contact area for the outdoor group is a pasture pen. The mobile shed used for the calvings now works as a shelter from wind, rain and sun for cows and calves. One part of the shelter makes up part of the outdoor calf creep, where calves have access to water, hay and concentrate and it is also equipped with a scale for weighing the calves. The cows can leave the contact area through a one-way selection gate (same as in the indoor set-up). Cows have access to water just outside this gate, to stimulate them to pass the gate. Once they have 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 in the 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 has been 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. All cows have now passed the first two weeks of lactation and they visit 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 give in lactation week two but this is not surprising since the cows also provide milk for their calf. The calves have grown around 1.3 kg/day so far.
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 in this project as calmly and gently as possible and 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 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 have access to the calves day and night. When the calves are around eight weeks the contact will be switched to half day, as a first step of the coming weaning and separation. During the half day contact period cows and calves will see each other and be able to make contact but suckling will not be possible. At around four months of age the calves will be moved out of the dairy unit. They will then weigh around 200 kg and are expected to start showing signs of puberty. They will be moved in groups and stay with calves they know from the contact area.
The project will run for at least three years. Additonal batches of CowCalf pairs will be recruited in March 2020 and again in the summer 2020. Cows in the project will be followed throughout the ongoing lactation and may enter the project again if their next calving is timed with a new batch of cows entering the project. 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, Aarhus University, Denmark
- Sabine Ferneborg, NMBU, Norway
- Rupert Bruckmaier, Vetsuisse Faculty, Switzerland
- Peter Krawczel, University of Tennessee, USA
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.