The use of a fresh pen continues to grow in popularity, especially for dairies that are expanding herd size and/or building new facilities. A fresh pen allows a dairy to house fresh cows separately from other cows in the lactating herd to facilitate monitoring of health problems, minimize social stress, and provide a diet specifically formulated for fresh cows.
The optimal duration for cows to remain in a fresh pen is unknown but likely is unique for each dairy and possibly each cow given differences in rate of increase in dry matter intake and milk production. An informal survey of dairies suggested that cows remain in a fresh pen anywhere from 10 to 42 days in milk (DIM) with 14 to 21 DIM the most common.
Fresh cows that transition successfully are typically ready for a move to a high group pen with a more fermentable carbohydrate diet between 10 and 14 DIM. Extended stays in a fresh pen can limit dry matter intake because of gut fill and increase the risk of health problems, such as primary ketosis. An example of this occurred at Miner Institute where the primary forage in the fresh diet, corn silage, had a lower fiber digestibility than expected based on initial laboratory analysis. Cows increased intake rapidly until 10 to 14 DIM when intake plateaued with milk continuing to increase. The cows were eating as much fiber as a percentage of their body weight as possible.
Blood beta-hydroxybutyrate (BHBA) started to rise at a time when it would normally decrease resulting in some cows having subclinical ketosis or showing clinical signs of ketosis. At 22 DIM, cows were switched to a more digestible high group diet that allowed greater intake and the primary ketosis problem resolved.
A fresh pen and its management can greatly influence fresh cow behavior. A fresh pen typically houses a smaller group of cows together than the other lactating groups which reduces the social activity and possibly leads to less social stress and more resting. This concept was demonstrated in a European study where the addition of fresh cows to small groups of cows compared to large groups of cows housed at 1 stall per cow resulted in fewer agonistic and nonagonistic interactions within the 3 hours after mixing. Introducing fresh heifers as pairs rather than individuals to a group containing older cows promoted lying behavior after mixing in the UK.
In a Danish study, cows housed as a separate group for one month after calving with ≥1 stall per cow resulted in improved production and health in primiparous but not multiparous cows. Interestingly, a fresh cow diet was not used in the separate group. An additional benefi t of separate grouping may be observed if an appropriate fresh cow diet is used.
The feed bunk of a fresh pen should be understocked and provide at least 76 cm of space or ≥1 headlock per cow. Limited feed bunk space increased the number of displacements and feeding rates of cows before and after calving in a University of British Columbia study. Fresh cows that were overcrowded at the feed bunk altered their feeding behavior (e.g. increased feeding rate) and increased the risk for health problems associated with slug-feeding in a collaborative study between Miner Institute and the University of British Columbia.
Based on fi eld observations and limited research, fresh cows should be housed in small, separate groups to minimize social stress, maximize comfort of the physical resting space, minimize slug feeding and other undesirable feeding behaviors, and provide a diet that promotes intake and prevents health problems.
Source: Miner Institute
