Efficacy of passive transfer of immunity in young calves is commonly assessed using total serum protein (STP) or serum immunoglobulin G (IgG) concentration tested within the first few days of life. To our knowledge, no research has measured changes in these concentrations over this period to establish an appropriate age range for testing. The aim of this study was to monitor changes in STP and serum IgG concentrations from birth until 10 d of age to provide a basis for recommendations for when passive transfer of immunity in dairy calves can be measured. Concentrations of STP and IgG of 12 calves were measured at 11 time points: at approximately 30 min before colostrum feeding, at 24 h after colostrum feeding, and daily from d 2 to 10 of age. Mean (± standard deviation) STP and IgG concentrations were 4.61 ± 0.3 g/dL and 0.6 ± 0.6 mg/mL at birth, 5.83 ± 0.73 g/dL and 22.2 ± 9.6 mg/mL at 24 h after colostrum feeding, and 5.78 ± 0.52 g/dL and 16.1 ± 7.3 mg/mL at d 10 of age, respectively. The IgG concentration declined over subsequent days relative to IgG measured at 24 h at a rate of approximately 0.69 mg/mL per day, declining by 27.6 ± 6.2% (mean ± SD) on d 10. The concentration of STP did not decrease over time. Concentrations of IgG at 24 h after colostrum feeding were highly correlated with each of the measures of IgG over the 10-d period (r ≥0.97). These correlations were supported by the Bland-Altman plots of agreement between the 24-h sample and subsequent samples. Compared with the reference value at 24 h, STP concentrations were highly correlated on d 2 and 3 (r ≥0.98), highly correlated but variable from d 4 to 9 (r ≥0.88), and lower at d 10 (r = 0.76). These results indicate that calves may be reliably tested for passive transfer of immunity using IgG or STP concentrations up to 9 d of age.
|Number of pages||7|
|Journal||Journal of Dairy Science|
|State||Published - Jul 2018|
Bibliographical noteFunding Information:
We thank the SCCL Ltd. (Saskatoon, SK, Canada) for the laboratory analysis of blood samples and technical support. We are grateful to the staff and students at the UBC Dairy Education and Research Centre for their help throughout the study. This research was supported by Canada's Natural Sciences and Engineering Research Council (NSERC) Industrial Research Chair Program awarded to MvK and DMW with industry contributions from the Dairy Farmers of Canada (Ottawa, ON, Canada), British Columbia Dairy Association (Burnaby, BC Canada), Westgen Endowment Fund (Milner, BC, Canada), Intervet Canada Corporation (Kirkland, QC, Canada), Novus International Inc. (Oakville, ON, Canada), Zoetis (Kirkland, QC, Canada), BC Cattle Industry Development Fund (Kamloops, BC, Canada), Alberta Milk (Edmonton, AB, Canada), Valacta (St. Anne-de-Bellevue, QC, Canada), and CanWest DHI (Guelph, ON, Canada).
© 2018 American Dairy Science Association
- calf health
- colostrum feeding
- failure of passive transfer
ASJC Scopus subject areas
- Food Science
- Animal Science and Zoology