Six Ways to Help Preweaned Dairy Calves Succeed in Group Housing
Group housing for preweaned calves has gained traction on U.S. dairy farms in recent years. Improvements in animal behavior and well-being, the potential for reduced labor costs and the opportunity to manage workloads more effectively are benefits often cited as reasons to adopt the practice.
The potential downsides are just as real and center on adverse health issues, such as the increased potential for scours and bovine respiratory disease (BRD).
That doesn’t mean group housing is a bad practice — there is no one-size-fits-all right way to raise calves. What it does mean is dairy producers need to evaluate their management practices to minimize the potential for negative outcomes, according to Theresa Ollivett, DVM, University of Wisconsin School of Veterinary Medicine.
“Indoor group housing exponentially exacerbates current weaknesses within the system,” Ollivett explains. “(Producers) need to be consistently better at everything in order to make group housing work. Abundant vaccinations and metaphylaxis are not the answers.”¹
Factors for consideration to improve outcomes in a group housing system include colostrum management, group composition and dynamics, nutritional management as well as early disease detection, according to Sandra Godden, DVM, and Whitney Knauer, DVM, University of Minnesota, College of Veterinary Medicine.²
Godden and Ollivett addressed best management practices for preweaned calves in group housing during the 2021 American Association of Bovine Practitioners (AABP) annual conference. The following six points are a summary of information they presented during the event.
1. COLOSTRUM MANAGEMENT IS A CORNERSTONE FOR EARLY CALF HEALTH.
In Figure 1, Godden outlines the five Q’s of good colostrum management.
An area Godden says many dairy producers still need to address is improving calf health through the transfer of passive immunity (TPI).
“According to a 2014 study, 14% of U.S. dairy calves failed,” she says. “So, in the average herd, there is still a large opportunity to improve this.”
The average cost of failed TPI in a dairy calf is cited in one meta-analysis as $70, Godden adds. She believes the losses could be greater because the meta-analysis ignored, or did not take into consideration, the lifetime production of the individual animal.
2. “OLDER” CALVES PERFORM BETTER IN GROUP HOUSING THAN YOUNGER ONES.
Godden recommends that calves be introduced to group housing at 12 to 14 days of age or even older.
Research shows younger calves take longer to learn to drink unassisted and need more guidance. They also drink less milk in the first days of life and have an increased risk of severe diarrhea and pneumonia (Figure 2).
3. GROUP SIZE IS ALSO AN IMPORTANT RISK FACTOR TO CONSIDER.
A 2006 randomized clinical trial of 892 calves in nine Swedish herds evaluated the health of calves placed in small groups of six to nine calves versus large groups of 12 to 18 calves. Researchers determined the large groups had a 40% increased risk for respiratory disease and also a reduced growth rate (Svensson et al., 2006. PVM 73:43).
Godden recommends housing in groups of seven or fewer calves. She notes that two calves — pair housing — could make the ideal group size.
The smaller group numbers don’t square with what some many distributors recommend to producers.
“They often suggest that farmers can put 25 to 30 calves on a nipple or in a pen, and it’s just not true,” Godden says. “People often learn that the hard way. As one of my colleagues says, ‘stocking density is self-correcting.’
“In addition to increased disease transmission, the major concern, if the group gets big enough, there’s a potential to introduce competition and aggression as stressors, and possibly limit intake, and those are going to feed back negatively on innate immunity, and, therefore, health,” she adds.
4. GIVE CALVES ROOM TO MOVE AROUND AND BED DOWN.
Both Godden and Ollivett emphasize adequate space is critical to success in group housing. Research indicates a stocking density that provides at least 45 sq. ft. to 50 sq. ft. bedded space per calf is desirable (Figure 3), and more is always better.
Keep age variations at a minimum, less than a week spread between animals if possible. Godden says when younger and older calves are group together, you see more competition, increased disease transmission from the older animals to the younger ones and an increase in mortality due to the age range (Jorgensen et al., 2017).
“Continuous flow pens contribute to endemic disease,” she says. “Pick your bug.”
5. WITH NUTRITION MANAGEMENT, FEEDING MORE MILK IS A POSITIVE.
Some producers might push back and say young calves will scour from having too much milk, but Godden says that is a myth.
“Feeding large volumes of milk does not cause milk scours,” she says.
When offered ad libitum access to clean, high-quality milk or milk replacer in the first days of life, dairy calves will drink an average of 8 liters per day by 4 days of age, and individual calves will drink up to 12 liters per day, without causing scours (Figure 4). Recent studies have reported a positive association between milk consumption very early in life on health as well as growth.
6. DO NOT RELY ON A COMPUTER TO DETECT SICK CALVES.
There can be large variations in calf feeding behaviors, especially in group housing, so use computers as an aid only to evaluate calf health. You might need to encourage producers to not rely on a computer algorithm to help detect animals that aren’t thriving.
“In addition to failing to detect clinical disease in many animals, a computer cannot detect subclinical BRD, for instance,” Godden notes. “We still need trained individuals on the farm to observe and identify sick calves.” BV
REFERENCES
¹Ollivett, Theresa. Calf Housing/Facility/Environment BRD Prevention. American Association of Bovine Practitioners Proceedings of the Annual Conference. 2021.
²S. M. Godden, W. A. Knauer. Management Considerations to Prevent Respiratory Disease in Group-housed Preweaned Dairy Calves. American Association of Bovine Practitioners Proceedings of the Annual Conference. 2021.
For more on this subject, read:
A Healthy Calf starts with Fetal Viability and Well-Being
