Research Summary - 2
Evaluation of oral Cryptosporidium parvum product in newborn calves on a commercial dairy farm
| Date/Time: |
8/28/2026
13:45
|
| Author: |
David Carter |
| Clinic: |
Immunology for Veterinary Practitioners |
| City, State, ZIP: |
Ames, IA 50010 |
D.P. Carter, DVM
1
;
M.W. Welter, BS, MA
2
;
1Immunology for Veterinary Practitioners, Ames, IA, 50010
2Oragen Technologies, Urbandale, IA, 50322
Introduction:
A major component of neonatal calf diarrhea is Cryptosporidium parvum, confirmed by PCR in 45.1% of diarrhea fecal samples 2019 - 2023 at Texas A&M VMDL, reported by Rodriguez, (2024). In 2010, Wyatt, Riggs, and Fayer published “Based on point-prevalence studies of multiple dairy farms combined with a 2-year long longitudinal study of one farm, it appears that virtually all calves on all farms become infected with C. parvum.” This remains the case today. The objective of this field trial was to assess the effect of an oral inactivated C. parvum preparation on incidence of therapy in calves less than 21 days of age when used in commercial dairy heifer production under the farm’s existing management practices.
Materials and methods:
The study site was a heifer raising operation for a 4000 cow dairy in the Midwest. The farm considered their neonatal calf health to be acceptable under their existing management protocols and did not have a clinically apparent C. parvum level of infection. Newborn heifers were fed colostrum and transported to a heifer raising site before calves were 24 hours old. At the heifer raising site calves were individually identified, blocked in groups of two by birth order, and randomly assigned to one of two treatment groups. Calves were housed outside in rows of individual hutches in arrival order with nose to nose contact down the rows. Test article containers, calf ID, hutches, and feeding bottles were prominently marked with a treatment group code and color which was blinded to content. One treatment group received the sham preparation and the other received the identical preparation containing the inactivated C. parvum component. Each calf in each group received 14 repeated doses of their respective test article (at 2/day feedings until 7 days old). Two ml doses of the appropriate test articles were added to individual milk bottles as they were fed. Treatments for each calf were documented at each feeding by individual calf. All calves received feedings without test articles days 8 - 21. Bottles and nipples were washed and disinfected between feedings and were not assigned to individual calves. The farm personnel followed farm standard procedures for evaluating the health of calves and administered the farm standard therapeutics for the conditions they observed including recording the medications, calf ID, and date and time of all therapies. The farm personnel were blinded to the content of both test articles. Since the farm personnel administered the assigned test articles at feedings, they were not blinded to the treatment group assigned to each calf. For 14 days in early May, all heifers born live were enrolled in the study. Two heifers died within 72 hours of birth because of dystocia and were not included in the data set. The study data included 38 calves receiving C. parvum inactivated test article and 40 calves receiving a placebo. Data analysis was independent student’s t test.
Results:
In the placebo group, 40 calves required 46 treatments for scours (1.15/calf). The 38 calves receiving the C. parvum preparation required 27 treatments for scours (.71/calf). This was a significant 38% reduction in scours treatments (p value =.048, ⍺ =.05) The 40 calves in the placebo group required 67 treatments (including scour treatments) for all health conditions (1.67/calf). The 38 calves receiving the C. parvum preparation were treated 33 times (including scour treatments) for all health conditions (.86/calf). This represents a significant 48% reduction in all therapeutic treatments (p value =.012, ⍺ =.05).
Significance:
Results indicate that oral use of inactivated C. parvum is significantly effective in reducing the treatments for disease in neonatal calves in a commercial dairy operation with the existing management and protocols. Short term benefits are reduced labor and medication costs. Others have published research showing the long term benefits from improved neonatal health in calves as improved milk production over multiple lactations.
