Pair Housing and Group Housing for Dairy Calves.

 By Heather Smith Thomas.

Young dairy calves have traditionally been housed in single-calf hutches, because this has been believed to be healthier than having contact with other calves.  Recent research and behavioral studies are showing that there are benefits to paired and group housing.

Dr. Bob James, a dairy consultant and owner of Down Home Heifer Solutions, Blacksburg, VA (Former Extension Scientist at Virginia Tech) specializes in calf management and nutrition, and works with many dairies across the country, helping them do a good job with their young stock.  “You look at how beef cattle are raised, and how we raise dairy calves and realize how unnatural this is and wonder why we are doing it this way,” he says.

“Some excellent research has been done at the University of British Columbia by scientist Marina (Nina) von Keyserlingk, PhD.  She has done some ground-breaking work.  Her students have gone out and continued these efforts and are changing how we think about raising dairy calves,” says James.

“I tell dairy farms that if they don’t want to feed more than 8 liters a day, don’t do group housing, because the calves will suck one another.  But if they provide adequate milk, this is not a problem.  A 6-week-old Angus beef calf will drink 10 quarts of milk a day, and the idea that we can feed a dairy calf only 4 quarts a day (which we’ve been doing for years and years) is not biologically normal and won’t meet their nutrient requirements for growth and maintenance during the first few weeks of life.

“The farm I am working with currently has 3-week-old calves drinking as much as 3 gallons of milk a day.  They don’t all drink that much; some only drink 2 gallons a day.  These calves are all healthy; some just have bigger appetites.  The feeding program that I really like, for the automatic calf feeder, is to feed them individually for a couple of days, just to make sure everything is fine, and they have a good appetite, and then we put them on the feeder, show them where the nipple is, and let them drink what they want.”  It’s programmed to only allow them to drink about 2 quarts at one visit. However, then they must wait 2 hours before the feeder will provide another meal.

“They can’t gorge themselves, but they have an adequate amount of milk during the day.  We do that for about 30 days, then reduce the milk—gradually, over a 4-day period—to about 2 gallons per day.”  What that does is stimulate the calves to start eating their starter grain.

“Then we hold them at that amount of milk for 10 to 14 days, then gradually wean them over another 10 to 14-day period by reducing the milk a little more each day, using the automatic feeder.  This gradual transition works very well.   It’s interesting to see 6-week-old calves ruminating and chewing their cuds,” says James.

Earlier studies showed that if you feed them more than 8 quarts of milk and then wean them abruptly by feeding them once a day the calves do poorly.  “That’s too abrupt a shift from very digestible milk to starter grain, and a tremendous insult to that animal’s biology.  It’s better to do it more gradually.  When calves are housed in pairs or group without auto-feeders a more gradual weaning is desirable.   Depending on the labor available on a farm we would hopefully cut back their milk in about 4 or 5 steps, over 2 weeks, rather than abruptly going to once-a-day feeding—which is traumatic for those calves,” he explains.

Getting people to feed dairy calves more milk is a real challenge.  “We are asking these farmers to spend more money.  Then we throw in the idea of housing them in pairs or groups.  This goes counter to long-standing veterinary recommendations of limiting calf-to-calf contact.  The veterinarians have not been very keen on paired or group housing, and I can understand that.  The risks of calf-to -calf contact must be managed by assuring that the farm has an excellent colostrum program, and if calves are in an indoor facility there must be very good ventilation and a high level of sanitation.  It’s not something you can cut corners on to save labor, or it will be a disaster,” says James.

On some dairies automatic calf feeders have been less than successful when shortcuts were taken.  “But the nice thing about the automatic feeders is that instead of spending time washing buckets and bottles, you can spend that time with the calves and be a better monitor of those calves,” he says.  James noted that the automatic calf feeders are more successful when there is a “calf manager” rather than just a “calf feeder”.

No one likes change, however.  “We are all guilty of this; we don’t want to change how we feed and manage calves, and historically dairies have strived to minimize costs on a daily basis by feeding less milk and weaning them early,—even though those heifers are their future,” he says.

How they are raised has a big impact in terms of how these animals behave as cows.  The paired and group-raised calves, when this is done right, are better adapted to herd life, have better health and longevity, better milk production, etc. so it can be well worth the effort when managed correctly.

“There are some tradeoffs, however, in terms of health.  On the plus side these calves have better health because they have better nutrition (more milk early in life), especially if you are buying a good-quality milk replacer or feeding milk and do a good job of keeping it clean and wholesome.  That’s a challenge because you must treat that milk just as you would the milk you are selling.  There are benefits, but there is also risk of increased disease transfer because calves are all together.  That’s where you must have a very good environment and a really good colostrum program.  If you don’t have those two things, you can expect to see problems.  Many people have bought the automatic calf feeders and abandoned them.  This usually occurred because of poor sanitation, poorly designed facility or personnel who lacked the skills to manage the system.   

Marina (Nina) von Keyserlingk, PhD, Professor, Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, started doing research in 2008, looking at social housing for calves compared with individual hutches.  “We evaluated the calves, not just on performance, but also in terms of their cognitive learning and behavior and their ability to adjust later to living with other calves, and how smart they are,” she said.

“Before we can consider pair housing or social housing, however, we have to be able to feed these calves in a way that they are not hungry,” she explains.  Otherwise they suck on one another.

“Many dairymen around the world are still feeding calves only 4 to 6 quarts of milk per day, usually split into two meals.  Many dairies don’t even feed with a nipple; they teach calves at an early age to suck milk out of a bucket.  People worry about the labor involved in feeding with bottles/nipples but then spend time teaching the calves to suck from buckets, because calves don’t learn it very quickly,” Nina says.

The important thing is to feed calves at least 8, and preferably 10 liters per day, for a Holstein calf, and Jerseys slightly less because they are smaller.  “The milk should be fed in at least 2 meals, and ideally 3 times per day.  This is more natural for calves—more like if they were nursing their mom,” she says.

“We have written many papers about this, and published another one recently that talks about how we’ve deviated from the natural way of doing things, in dairy systems, and some of the consequences and costs of that.  You must be feeding the milk through a nipple; all young mammals need milk, and are highly motivated to suck.”  Suckling is crucial for their survival and also their well-being and comfort.

“Some farmers use nipples but are frustrated because they feel the calves take too long to drink, so they make the hole larger, which is not a good thing.  You need to make them work for the milk,” she says.  Calves have a need for a certain amount of suckling; it takes a bit of time to nurse their mothers if they are raised on a cow.  Even after they empty the udder they continue to suckle, bunting and stimulating the cow to let down every last bit of milk.  Calves are much more satisfied if they have enough suckling time.

“We had quite a bit of evidence to show that the traditional practice of providing only about 4 liters of milk per day left these calves very hungry.  We measured this by counting how many times they came back to the milk feeder.  We used computerized feeders and the computer was programed so the calf would get half of its milk in the morning and half in the afternoon, and we could see how often they came back to try.”

After being moved from individual housing to groups, there might be 20 calves at one feeder, constantly sucking on one another because they were still hungry.  “They were continually going to the feeder and spending up to two hours a day next to the feeder waiting for milk.  There would be 19 other calves that were unable to drink—and sucking on each other.  We were able to show this hunger behavior by these repeated non-nutritive visits, as they were looking for milk,” Nina says.

“Only after you are feeding higher volumes of milk, via nipple, can you think about social housing.  If you don’t do that when you put them into social housing, the calves will cross-suck repeatedly,” she says.

“We had a PhD student who published a paper on pair housing, and how it works in terms of weaning and grain intake.  All the calves were given the same amount of milk—8 liters a day, getting 4 liters in the morning (for 2 hours) and 4 liters in the afternoon (during a 2 hour period).  They all had access to grain, hay and water in the pen.  The only difference between the calves in this study was that half of them were individually housed and half were paired,” Nina says.

“One of the fears farmers have is that if they feed more milk, the calves won’t eat grain.  This is true at first because most calves in the first weeks of life (even beef calves) are just drinking milk.”  They start nibbling solid feed; beef calves mimic mom and start eating what she’s eating when they are just a few days old, and eat increasingly more as time goes on--but are not eating much volume at first.

“They don’t need solid feed for nutrition because they are getting all they need from mama’s milk.  They simply nibble and start the rumen functioning.”  Beef calves start chewing their cud within a couple weeks, and the rumen begins to develop.  This is all part of the transition that helps them become a ruminant.

“In a dairy calf, however, we are trying to make that animal do this in a very short time, trying to force it.  Even when fed limited amounts of milk (to try to get them eating solid feed quicker) they consume very little grain until they are 3 or 4 weeks of age, just because they can’t process it.  So they don’t grow very well because they are not getting enough nutrition,” Nina explains.
She recommends feeding calves as much milk as they want, in those first 3 to 4 weeks of life, and then you can reduce the amount of milk a little, and their consumption of starter grain increases.  

“We also found that the pair-housed calves eat more grain than the single-housed calves.  This may be similar to calves mimicking mom.  We think that when they are socially housed, one calf sees the other calf look at the grain bucket and so it goes to look in the grain bucket, too.”  Cattle always eat better in groups or with a buddy.  They are social eaters.

“We measured grain intake during the milk feeding period and found significant increase in consumption in calves that were pair housed, compared to those in single hutches, even though they were all fed the same amount of milk.  The big problem for farmers, for feeding lots of milk, is that they are used to weaning calves abruptly.  When feeding higher volumes of milk and trying to wean the calf (at a much earlier age than it would ever be weaned in nature), and it is drinking lots of milk, you cannot just suddenly stop feeding the 8 or 10 liters of milk,” she explains.

Some dairies abruptly wean calves as early as 40 days and some at 6 weeks, or 8 weeks.  It depends on the management of the farm and how much milk they have, but regardless of how you do it, it’s much better for the calf to have a gradual transition.  “You have to slowly reduce the milk, over 5 to 7 days.  This is much less stressful for the calves and their grain intake goes up,” she says.

 “We did a trial in which we reduced the amount of milk over 5 days, and kept the calves in their pens (individual pens and pairs).  They were all in the same barn, but the individual calves could only see the calves across the alley; there were solid walls between pens.  The paired calves could also only see the calves across the alley, but had their buddy with them,” Nina says.

The graduate student doing the trial measured how often the calves vocalized when the milk was finally taken away.  “She always weaned a pair and a single at the same time.  We saw 2.5 times as many vocalizations from the individually-housed calves as we did from the pair-housed calves.”

Nina reminds farmers that when you have to go through a stressful event, it’s better to go through it with a friend than by yourself, and it’s the same with calves.  “This is what we call social buffering.  Even if we take the milk away slowly, it’s still stressful, but because they have this other calf with them there is some social buffering to mitigate the stress,” she says.

In the group-housed calves being weaned, there were already three calves in each pen that had been weaned for many days and already eating starter and doing fine.  “We had starter grain in a computerized feeder, where calves must walk through an alleyway to get to the grain.  In the group, when one calf is in there eating the grain, the other calves can’t box them out,” she explains.  

“While they were still in individual and pair-housed pens they were eating grain from a bucket, so they had never seen this chute before—that they had to enter to get to the grain.  We took a pair and an individual and dropped them into a group pen with 3 calves that already knew where the grain was.  We measured how long it took for the newcomers to have their first grain meal.  The pair-housed calves, on average, took 9 hours to have their first meal.  The individual-housed calves took 2 days.  That’s a huge difference,” Nina says.

“The individually-housed calves lost about 6 pounds in 48 hours, whereas the pair-housed calves didn’t lose any weight.  Once they knew what they were doing they kept eating the grain.  We weighed them every couple days and they started increasing weight as expected.”

What was interesting with the individual-housed calves, when they finally did eat grain, they ate a lot of it because they were so hungry.  “Then they went off feed and we suspect it was because they got rumen acidosis and a tummy-ache.  After being off feed and the rumen pH coming back up again, they were super-hungry again and overate again.  It’s a vicious cycle.  The only other time we’ve seen this yo-yo pattern is in feedlots where cattle are on high-grain diets.  They eat too much and feel sick, and don’t eat, then overeat again.”

The calves in this trial were observed for 2 weeks.  “The individual-housed calves were still yo-yoing at 2 weeks, whereas the pair-housed calves never missed a beat and just kept eating.”

In a subsequent trail, doing the same thing, calves were reared individually and pair-housed.  “Then in an open arena we put an individual-housed calf with an unfamiliar pair-housed calf.  These were calves that had never seen each other, though they were the same age.  We put them together in this large area for 15 minutes and watched what they did.  The pair-housed calf slowly walked up and tried to sniff the individually-housed calf, and was calm, whereas the individually-housed calf was totally freaked out and running around.  Its entire focus was on the other calf but it was too scared to get acquainted.  The time taken to touch the other calf was significantly longer with the individually-housed calves, compared with the pair-housed calves,” she says.

“Once the individually-housed calves had the courage to touch the other calf, then it wouldn’t leave it alone.  It didn’t understand or have any feel for personal space.  We also put two pair-housed calves together, that had never met each other, and they simply went up and sniffed each other, and then together they walked around exploring the pen.  By contrast, the individually-housed calves never really explored their environment; they were too nervous/scared and focused on the other calf.”  They never relaxed.

“I visited a big farm last year that had individual housing for the calves and they were weaning and putting them in a group pen.  I asked what they did with them then and they said they don’t do anything with them during the first week because they are so crazy.  I understand why they are crazy, with that abrupt change, but we need to figure out how we can keep them from being crazy.  This is where social housing—either pairs or groups—comes in,” Nina says.

“In the study we did, we took the individual and pair-housed calves and trained them to play a game.  In a large pen we put a black X on one side, and they had to learn that if they nose-touched that black X, they got a milk reward.  There was a plain white square on the other side of the pen, and if they went there, they got no milk.  No matter how they grew up, they could all learn how to play this game.  We then switched the game.  If at first they got milk with the black X, suddenly they didn’t get milk at that spot; they had to go to the white square.”  They had to learn the difference, and do the opposite.

“Pair-housed calves take about a day and a half to learn this, while individual-housed calves rarely do.  Almost none of them learn to switch; they continually go back to what they learned first,” she says. 

“We redid this with pair-housed calves, and calves reared with their mother, and with social housing.  This time we used a computer screen (a method used in dogs) and taught the calves to touch a start box with their nose.  This is their signal to us that they are ready to play the game.  They nose-touch the start box, and we had a computer screen at the back of the pen.  They either learned that white was positive (if the screen was white they would get milk) or red.  Half the calves were taught that if it was red, they got milk.  If it was the other color they didn’t get milk.  All calves could learn how to play the game, but when we did the reversal, the pair-housed calves and the calves reared with their mother (the socially-housed calves) took a day and a half and switched.  Again, the individually-housed calves kept going to the original color that they had been taught first and never figured out the switch.

“I’ve spoken about this in farmer meetings, and I remember one farmer saying this makes sense: ‘I have a parallel parlor and cows learn how to go into the parlor on the left side.  If they end up on the right side, its chaos, because all of sudden they have to turn the other way.’

“One benefit is that the pair-housed and socially-housed calves are very calm.  The other huge benefit is the fact that as we wean calves, it’s a better story to tell the public that these calves are socially housed, compared to individually housed.  One of the big issues today is separation in the dairy.”  Social housing is more acceptable in the public eye, as well as being better for the calves.
“We started pair housing/social housing in 2008 on our research dairy and know that feeding calves more milk will improve health, and pair housing improves their ability to become more adaptable and deal with stress.  It’s more natural, and simply the right thing to do,” she says.

Change can be hard, however.  Dairies are accustomed to doing economic models and figuring out how much milk replacer to buy—wanting to spend less money.  “We also know, however, that when calves are not fed enough milk, there are higher rates of disease, and other issues.”  If a person is trying to raise good replacement heifers, skimping on milk or milk replacer is counterproductive.
“There is a lot of evidence showing that if you feed higher volumes of milk during the first 3 to 4 weeks of age, those heifers will produce more milk later in life.  They are off to a better start.”