Research Summary - 3
An evaluation of calf management practices and health outcomes on midwestern organic dairy farms
| Date/Time: |
8/29/2026
08:15
|
| Author: |
Carmen Burner |
| Clinic: |
University of Minnesota |
| City, State, ZIP: |
Saint Paul, MN 55108-2020 |
C.M. Burner, MS
1
;
L.S. Caixeta, DVM, PhD
1
;
W.A. Knauer, VMD, PhD
1
;
J. Barlow, DVM, PhD
2
;
J. Lombard, DVM, PhD
3
;
V.S. Machado, PhD
4
;
C.S. McConnel, DVM, PhD
5
;
N.R. Noyes, DVM, PhD
1
;
1Department of Veterinary Population Medicine, University of Minnesota, Saint Paul, MN 55108
2Department of Animal and Veterinary Sciences, University of Vermont, Burlington, VT 05405
3Department of Clinical Science, Colorado State University, Fort Collins, CO 80523
4Department of Veterinary Sciences, Texas Tech University, Lubbock, TX 79409
5Department of Veterinary Clinical Sciences, Washington State University, Pullman, WA 99164
Introduction:
Modifications to the USDA National Organic Program require dams to be under continuous organic management in the last trimester of gestation, making healthy, organically raised youngstock the primary source of replacement cows. As a result, organic dairy farmers need to optimize youngstock outcomes to sustain herd size, with youngstock performance becoming a primary driver of profitability and long-term resilience. The objectives of this ongoing study are to describe management practices and calf health on organic dairy farms.
Materials and methods:
Certified organic dairy farms in Minnesota (n=7) and Wisconsin (n=3) were enrolled in August 2025 and are undergoing quarterly visits for one year. At the first visit, an oral survey on herd management practices was administered. At each quarterly visit, up to 2 preweaned and 2 postweaned calves were enrolled. Bilateral nasal swabs, fecal sampling, and thoracic ultrasonography were performed on enrolled calves. Additionally, blood sampling occurred on all calves 1 to 7 days old to test total serum protein. Nasal and fecal samples were submitted for pathogen detection via qPCR and flotation, respectively. Survey responses and calf health data from the first two visits were summarized descriptively.
Results:
Enrolled farms have been certified organic for 20 ± 6 years, with a median (range) milking herd size of 111 (45-650) cows. Reported sources of colostrum included from the dam (40%), pooled colostrum (30%), calf kept on dam (20%), or from another cow (10%). Of the 8 farms hand-feeding colostrum, calves were provided 2.3-5.7 liters at first feeding. Brix refractometers were utilized by 40% of herds, with the average (±SD) minimum accepted Brix% of 22.4 ± 0.5%. Weaning occurred on average (±SD) at 92 ± 36 days. The main health concern for calves was reported as digestive (e.g., bloat, diarrhea; 70%) and respiratory (30%) concerns. On-farm measurements further charachterized calf health outcomes, with total serum protein among calves 1 to 7 days old (N=65) were categorized as “excellent” (> 6.2 g/dL) for 49% of calves and “good” (5.8 to 6.1 gd/L) for 23% of calves. A total of 30 preweaned and 26 postweaned calves were enrolled to date. Mycoplasma bovis was the most prevalent respiratory agent in nasal swabs among preweaned calves (9/30). In postweaned calves, Mycoplasma bovis (6/26) and Bovine Coronavirus (6/26) were the most prevalent. Lung ultrasound scores indicating mild or more severe pneumonia were found in 11/30 preweaned and 9/28 postweaned calves. Eimeria sp. oocysts were detected in 18/24 preweaned and 16/26 postweaned samples with median (range) counts of 650 (50-2,350) and 100 (25-7,225) oocysts/g, respectively.
Significance:
Preliminary results from this study suggest there is an indication of respiratory compromise and gastrointestinal parasites among preweaned and postweaned calves on organic farms. Further analysis of this data will investigate associations between management practices and calf health outcomes.
