Rest is an essential component of not only cow productivity but also of animal welfare. Optimizing rest time is critical, but according to Nigel Cook, MRCVS, with the University of Wisconsin-Madison School of Veterinary Medicine, cows on many farms are not getting the ideal 12 hours of rest per day.
For cows housed in barns, stalls are a key part of the resting time equation. Cook spoke about optimizing that resting space during a Dairyland Initiative “After the audit” workshop.
Read between the hocks
The surface of a stall has a lot to do with comfort, and hock injuries can be used as an indicator to evaluate stall surfaces. Injuries include hair loss, swelling, abrasions, or ulcerations on the hocks.
Many farm assessment programs use hock scoring as one measure of cow welfare, and worldwide, there is a fair amount of data published on hock injuries. Unfortunately, those results are less than desirable.
“We have a problem,” Cook said. “About half of the cows globally — 53% — have some level of hock injury.”
For the most part, cows are experiencing abrasion injuries, as they are often moving their legs across rough surfaces.
There is a relationship between severe hock injuries and lameness, Cook explained. Lameness drives changes in stall-use behavior. Lame cows don’t get up and down as easily, and they stay lying down on one side longer than normal. This can result in swollen or ulcerated hocks that are equivalent to pressure injuries or sores in bed-ridden humans.
“Cows with lameness are more likely to suffer from severe hock injuries later,” Cook noted.
Bedding plays a role in minimizing hock injuries. Cook said cows in deep-bedded stalls have a much lower prevalence of hock injury than in stalls with less bedding. Even with deep bedding, injuries can occur, and that is often a function of the curb.
“Lying position of the cow becomes very important,” Cook shared. “Fix the lying position, get the cow up on the platform, and maintain the bedding depth so that you cover up that curb.”
There is less data available on knee injuries, but Cook noted there is a similar global problem. He said that, especially in herds using recycled sand, cows can grind the hair off their knees when getting up and down.
Some of the risk factors for hock and knee injuries can be reduced with deep bedding and maintaining bedding in the stalls. Farms can also increase the resting space length and reduce the duration of the housing period by providing cows access to pasture.
Focus on the surface
“Big, bony cows really value soft surfaces,” Cook said. “The softer the bedding, the better. Deep bedding is best.”
Bedding varies across the world, with farms using sand, manure solids, sawdust, straw, paper, and even peat moss. Dairies can do a great job utilizing these different materials, but Cook indicated that herds with sand bedding make about 2,000 pounds more milk in a lactation when compared to mattress cows.
It is possible to convert from a mattress surface to a deep bed. One method Cook shared was to remove the concrete and re-pour the curb. A less costly alternative is to attach a fiberglass pipe, rubber landscape timber, or treated landscape timber to the rear of the stall. This can be done in freestalls or tie stalls.
Whatever way that curb is added, Cook advised to keep the height to less than 14 inches. Much less than that, though, and the stalls must be bedded more frequently. Although heifers don’t like backing off of a tall curb, “Cows will tolerate 14 inches with a comfortable surface quite well,” Cook said.
Once stalls are converted, the deep bedding has to be managed. “If you don’t deal with it, cows do weird stuff,” he said. “You will lose lying time as cows nest and dig.”
Most farms add new bedding two times per week, while some can bed once a week.
If using manure solids, Cook recommended putting it through a drying process. “It seems to make the material a whole lot better for animal health,” he said. “But there is a cost to drying it.”
If using mattresses, Cook said to look for cushion. This could include rubber and foam.
“Try to provide the softest mattress you can, plus cover it with a lot of bedding,” Cook shared.
The resting space
Design stalls that cows want to be in, and a place where cows can rest without compromising neighboring stalls.
“We now have good data showing that more resting space, wider stalls, longer resting time, and less lameness are worth the investment,” Cook said. Better stall occupancy is a result of creating those individualized resting spaces, he explained.
Limit obstructions to natural movements. This includes space for a cow to lunge and bob when it stands up. Lunge space, he said, is the horizontal movement a cow makes when getting up. The bob space is in front of the stall or to the side, where a cow’s head goes down while the animal is taking weight off its back feet in order to stand up.
Obstructions in stalls can include the brisket locator and stall loops. Having no brisket locator may work fine in stalls with a short platform, but in longer stalls, cows get dirty and challenges arise from that.
“I think we need some kind of brisket locator, but we need to be careful how we design it,” Cook explained.
He recommended that the brisket locator be no more than 4 inches tall. “Anything higher prevents the cow from doing natural front leg movement and makes it more difficult to get up and down. An inch can make a lot of difference to a cow,” Cook said.
To keep them clean, cows must be positioned appropriately in the stall. “We want to create a big space that the cow is comfortable in, but don’t want it to lie diagonally, get dirty, and get mastitis as a result,” Cook said.
Encouraging cows to lie straight in the stalls is called indexing. Cook said farms can overdo it, though, by adding more metal to the stall, including misplaced stall loops and neck rails.
“We want to index by design, not by restraint. If we do it by restraint, we create injuries and reduce lying time,” he said. Cook recommended the angle of the lower stall divider rail be 20 to 22 inches behind the brisket locator.
The neck rail helps position the cow in the stall when it is standing and has less of an impact on the lying position. Proper standing position limits manure in the back of the stall. In mattress herds, the cow should be able to stand squarely in the stall (with the neck rail placed directly above a properly located brisket locator), while in deep-bedded herds, the neck rail is placed 6 inches closer to the rear curb to avoid contaminating the bedding with manure and urine. Correct neck rail height is about 48 to 50 inches above the stall surface.
A cow should spend half of its day lying in a stall. While there are certainly many aspects of dairy barn design that take careful consideration, the resting space may be one of the most critical elements to get correct.