The postpartum dairy cow is at high risk of disease and requires ample access to feed and rest. Despite this, a newly fresh cow faces many management and housing changes after calving. In a study we recently conducted at Aarhus University’s cattle facility in Foulum, Denmark, we asked if keeping the group size small in the fresh pen reduces competition for feed and freestalls, and improves dairy cow welfare during this sensitive time.
Cows were moved from an individual maternity pen into a fresh pen four days after calving. The fresh pen either had six cows or 24 cows, but stocking density remained the same (one cow to one feed bin and one freestall). We found that:
- There was less competition in small groups of six cows than in larger groups of 24 cows.
- Minimizing competition by housing dairy cows in a small group for the first period after calving may improve cow welfare.
- On the first day after introduction to the group, both feed intake and lying time was low for both groups, suggesting cows took time to adapt to the new environment.
- Regardless of group size, sick cows had a lower feed intake than healthy cows, and were also involved in less competition over freestalls.
A smaller group size post-calving can reduce competition
Shortly after giving birth, dairy cows are typically moved to a large group of cows. However, when a cow is introduced to a new group, she typically encounters aggression from other cows and may face problems accessing feed and freestalls due to competition. Dairy cows will show aggressive behavior toward a newcomer in the group so they can determine the social status of each group member. You may see this aggressive behavior in the form of “displacements” from the feeding and lying spaces, where cows will physically push a newcomer out of the feedbunk or freestalls.
We predicted that in a smaller group, there are fewer cows that need to show aggressive behavior to establish their social relationship with the newcomer. After we regrouped cows into groups of six or 24, we closely monitored the cows’ social behavior to see if competition was lower in the smaller group. Indeed, we found cows regrouped into a smaller group of six experienced less competition than cows regrouped into a larger group of 24.
During the first day after introduction to the new group, cows in groups of 24 were physically pushed by another cow four times more frequently than cows in groups of six. Furthermore, newcomers in groups of 24 displaced other cows from feed bins 4.7 times more frequently than those in the groups of six. The higher displacements of newly introduced cows in groups of 24 illustrate that these cows had more difficulty accessing the feed bins than cows in groups of six. Despite the same stocking density, the larger group size made it more difficult for the new cows to find an available feeding space, making them more likely to try to push out other cows from feeding space.
These difficulties accessing a feed bin also meant that cows in groups of 24 cows had 40 percent more visits to feed bins on the first day after introduction compared with cows in groups of six. This suggests that these cows were not able to stay at one feed bin for a long period of time to consume their TMR. Together, these results illustrate that being introduced to a smaller group reduces the aggressive behavior experienced by a newly introduced cow.
In our study, cows were moved to their new pen in the morning at their normal feeding time without being fed. Moving cows when they were very hungry may also have contributed to the newcomers working hard to get access to feed. Instead, we suggest moving cows to a new group only after they have had a chance to feed at their normal feeding time, as this may help reduce aggression.
Cows take time to transition into a new fresh pen
Regardless of group size, we found that cows had the lowest feed intake and lying time on the day they were moved into the fresh pen compared with the next few days. For cows in both groups, feed intake increased 20 percent from the first day to the third day after they were moved. The feeding rate of cows was also highest on the first day after moving, suggesting that cows were experiencing competition and eating quickly as a result. Also regardless of group size, cows only spent seven hours lying down on the first day after moving, which was more than 30 percent lower than the next two days (10.5 and 11.1 hours of lying time on day two and three after regrouping, respectively).
The low feed intake and the low lying time on the first day after cows are moved into a fresh pen emphasize the importance of ensuring ample resources (feeding and lying space) are available to cows during this first day. Previous research from the University of British Columbia’s Animal Welfare Program found that lying time in mid-lactation cows increases when freestalls are not overstocked (one stall per cow versus one and a half stalls per cow). Since fresh cows likely need rest to recover from labor, understocking combined with small group sizes may better ensure fresh cows are getting adequate lying time.
Sick cows are the least likely to compete
Before cows were moved into the fresh pen, we examined them to determine their health status. A portion of the cows moved into the fresh pen had a previous illness (e.g., milk fever, mastitis, retained placenta, subclinical ketosis or subclinical metritis). When we compared these previously sick cows with healthy cows, we found that regardless of group size, sick cows ate less and engaged in fewer displacements from the freestalls compared with healthy cows. This result suggests that sick animals may particularly benefit from fresh or hospital pens that give them ample space to feed and to rest and recover from their illness.
Designing your fresh pen around the cow
Our study highlights the need to think about the fresh pen, or any pen that a cow is entering soon after giving birth, from the perspective of the cow. The cow has recently undergone a painful labor and is trying to navigate a new social environment that may put constraints on her ability to consume feed and get the sufficient rest that she needs. Having a smaller fresh pen where newly calved cows can adapt to their new environment before entering a large pen is one way to help the cow cope with the challenges that occur during transition. 
Margit Bak Jensen is a senior researcher at Aarhus University, Department of Animal Science.
Kathryn L. Proudfoot is a animal welfare specialist at The Ohio State University, Veterinary Preventive Medicine.
PHOTO: Fresh cows have recently experienced a painful labor and are trying to navigate a new social environment that may put constraints on their ability to consume feed and get sufficient rest. Having a smaller fresh pen where newly calved cows can adapt to their new environment before entering a large pen is one way to help the cow cope with the challenges that occur during transition. Staff photo.
