Editor’s note: The following was provided by Corwin Holtz, dairy nutritionist from Dryden, N.Y.

Seventeen months ago, if someone had told me that group-raising calves was the way to go, I would have said they were nuts!

You can “teach an old dog new tricks,” I guess. As one of my clients clearly states, it is not for everyone. But for some of my clients, it has been and will be the right way to go.

I saw my first “system” in eastern New York in August 2010. It was in a modest barn (ventilation was good for that time of the year) and my most vivid recollection was that he needed to wean these calves — they were six to seven weeks of age — or he will be in the veal rather than dairy heifer business. Yet it was the most solid, slick, healthy groups of calves I had ever seen. I walked away telling myself that I had to at least investigate this and visit with a few clients that might be able to make such a system work.

Since last fall, I have had seven clients set up systems — one is a computerized system the others are free-choice. And, there are six more clients looking to get started once spring rolls around.

It has been, and continues to be, a learning experience for all of us. But, thus far, the hiccups have been minimal. When issues arise, we are able to quickly figure out what needs to be done differently or better.

The free-choice clients are a combination of waste/high-SCC/saleable milk and some milk replacer. All of these are acidified with dilute formic acid, except for the milk replacer which is pre-acidified with citric acid. After proper acidification, it is true free-choice 24/7. For budgeting purposes, I am figuring 2.5 gallon/day intake from day 1 to weaning at six to seven weeks. At six to seven weeks, they will be consuming 3+ gallons. Free-choice water and free-choice grain is offered to groups from day 1.

Some things we have learned:

  • pH must be in the 4.1-4.4 range (pH checked every batch that is acidified, every day). Have found that narrow range pH paper works just fine for monitoring.
  • Milk must sit for 12 hours post-acidification for proper kill; milk replacer can be fed right away.
  • Absolute minimum of 30 sq. ft./calf of bedded pack (prefer straw for pack area). Forty would be that much better but 30 works well.
  • No more than five calves per nipple. (I prefer no more than four).
  • Milk needs to be agitated during the 24-hour period (have some systems out of Canada with a timer, agitating 15 seconds every 30 minutes).
  • If milk replacer is used, it needs to be a minimum of 24 percent CP — Cornell University researcher Mike Van Amburgh says 26 percent. — and highest fat content available. Needs to be formulated at a 13-14 percent solids content (mimic Holstein milk).
  • Still need a good calf manager! Time spent though will be milk prep and delivery, but most importantly calf observation.
  • Group size: have seen anywhere from eight to 35 and everything in between. As long as the square-feet and calves-to-nipples rules are adhered to, the larger groups seem to work well. (Probably takes a better calf person in order to have proper observation). Group size is also a function of calving pattern in the herd. I would like to see no more than a 10-day spread in age (Seven would be more preferable).
  • Milk temp needs to be >70 degrees, but doesn’t need to be hot. Still sorting through this issue and how we best warm the milk post acid, as acid addition needs to be done at around 60 or it can curdle.
  • My bias (and clients agree) is that weaning is done over a few-day period by solids dilution (i.e. today 100 percent acid milk, day 2 25 percent water, 75 percent milk, day 3 50:50, day 4 75:25, day 5 water). This appears to be the approach that best prevents sucking across calves — very minimal to begin with, but this seems to take care of it close to 100 percent. Also, as this approach is taken, grain intake skyrockets!
  • VENTILATION! This is the key. If milk is done properly, the digestive issues are pretty much gone and the health issue with calves grouped like this is respiratory. We have been working with a company out of Canada on positive-pressure systems and following some Wisconsin work that thus far seems to be delivering results. Still a work in progress, and every facility is different, but I believe the issue is surmountable and we will be able to build and manage to minimize potential issues.

So, why are my clients happy?

  • Healthier calves. I believe these higher levels of milk intake from day one have taken immune function to another level.
  • Growthier calves, easily hitting Van Amburgh’s “double birth” weight by 56 days.
  • Less labor and labor is working indoors. My best data on this is a client with 70-80 calves (four groups). Weekly labor (mixing, delivering, monitoring/treating calves, cleaning equipment, bedding, record keeping, etc.) is averaging 25 hours/week.
  • Animal welfare. Nothing like seeing a bunk of calves “hanging out” or, depending on the time of day, “running an Indy 500” around the pen.
  • Quiet! They don’t associate people with feeding time. Amazing to stand in a barn for an hour plus and not hear one (and I mean one) calf make a noise.
  • Transition issues. The socialization that sets calves back coming out of single housing systems is taken care of from day one. As I mentioned before, grain intake skyrockets and we don’t see the typical “transition period” set-back.
  • It has put enjoyment back into milk-fed calf-raising.

I am sure that I have maybe missed something but I think I have hit the highlights. It has certainly been an exciting project for me as a consultant and fantastic to see the positive results for my clients.