Condition of surplus dairy calves during marketing: a cross-sectional study

Authors: MAGGARD, HANNAH - The Ohio State University; HABING, GREGORY - The Ohio State University; RENAUD, DAVE - University Of Guelph; PROUDFOOT, KATHRYN - University Of Prince Edward Island; ENGLAND, ZACHARY - The Ohio State University; CHENG, TING YU - The Ohio State University; WILSON, DEVON - University Of Guelph; MORAN, MEGAN - The Ohio State University; Pempek, Jessica

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2023
Publication Date: 11/2/2023
Citation: Maggard, H., Habing, G.G., Renaud, D., Proudfoot, K., England, Z.A., Cheng, T., Wilson, D., Moran, M., Pempek, J.A. 2023. Condition of surplus dairy calves during marketing: a cross-sectional study. Journal of Dairy Science. https://doi.org/10.3168/jds.2023-23625.
DOI: https://doi.org/10.3168/jds.2023-23625

Interpretive Summary: More than half of the dairy calf population is sold soon after birth in North America. Very limited research, particularly in the U.S., has assessed calf condition during marketing at livestock dealers (or licensed facilities where individual or small groups of calves are aggregated into larger cohorts for veal or dairy-beef production). This study assessed the clinical health of 1,119 calves on arrival at 2 livestock dealers. One blood sample per calf was also collected to measure serum total protein levels, an indirect measure of transfer of passive immunity and colostrum management on the dairy farm of birth. Calf dehydration (assessed via skin tent test) and navel inflammation were the most prevalent clinical concerns, and male calves were more likely than female calves to have navel inflammation. Nearly one-fifth of calves had failed transfer of passive immunity or did not receive adequate colostrum. These results highlight opportunity for future research to improve surplus calf condition prior to arrival at livestock dealers.

Technical Abstract: Surplus dairy calves are sold soon after birth and marketed through a live auction or livestock dealer (i.e., a facility where large groups of calves are aggregated) before entering veal or dairy beef production chains in the United States. Our previous work demonstrated that veal calves arrive to calf-raising facilities with failed transfer of passive immunity (FTPI) and clinical signs of disease, but little is known regarding calf condition during marketing. The objectives of this cross-sectional study were to 1) estimate the prevalence of FTPI and suboptimal health outcomes in surplus calves on arrival at livestock dealers and 2) determine risk factors for suboptimal health, including calf sale body weight, sex, and source. Two livestock dealers in Ohio were visited 2 to 3 times per week, with approximately 28 calves enrolled in the study per visit for a total of 1,119 calves. One blood sample per calf was obtained to evaluate FTPI by measuring serum total protein levels (using a cutoff < 5.1 g/dL). Calves were clinically evaluated for signs of navel inflammation, depression, dehydration, fever, diarrhea, respiratory disease, and arthritis; health outcomes were dichotomized using clinically relevant cut-points. Descriptive statistics were used to describe the prevalence of calves with suboptimal health outcomes. A multivariable logistic regression model was used to determine if sale body weight (<40.8 kg vs >40.8 kg), sex (male vs female), and source (dairy farm of birth vs live auction or livestock dealer) were risk factors for health outcomes. Nineteen percent (206/1091) of calves had FTPI, and calves purchased directly from the dairy farm were more likely to have FTPI compared to those purchased from a live auction or livestock dealer. Upon clinical examination, 69.2% (769/1112) of calves were considered dehydrated, 26.3% (293/1112) had navel inflammation, and 7.33% (82/1118) were depressed. Males were more likely than females to have navel inflammation and ocular discharge. This research highlights the opportunity for continued improvements in colostrum management for female and male surplus dairy calves. Strategies to mitigate dehydration and navel inflammation are also encouraged before calves enter veal or dairy-beef production chains. Key Words: Failed transfer of passive immunity; health; marketing; surplus dairy calf.