Identification of biomarkers measured upon arrival associated with morbidity, mortality, and average daily gain in grain-fed veal calves

Abstract

There is a strong need for management strategies that help reduce the incidence of disease and subsequent antimicrobial use in the veal industry. Biomarkers could serve as useful tools that allow producers to take preventative measures before clinical problems occur. The objective of this prospective cohort study was to identify biomarkers measured upon arrival associated with morbidity, mortality, and average daily gain (ADG) in grain-fed veal calves. Upon arrival at a grain-fed veal facility in Ontario, Canada, calves were weighed and health-scored using a standardized healthscoring system. Several metabolites were measured including creatine kinase (CK), cholesterol, haptoglobin, manganese, serum total protein, iron, cobalt, zinc, selenium, molybdenum, and IgG. Farm personnel treated calves according to their farm protocol and weighed them at 78 d after arrival. Performance, treatment, and mortality records from the facility were used for analysis. Multivariable Cox proportional hazard models were created to evaluate metabolic biomarkers associated with morbidity and mortality. A mixed linear regression model was created to determine biomarkers associated with ADG. A total of 992 male dairy calves were evaluated at arrival from January to December 2017. Of the calves evaluated, 74 calves (7.5%) died and 877 (88.4%) were treated for illness over the 11-wk period under observation. Higher levels of haptoglobin and molybdenum were associated with a greater hazard of morbidity, whereas higher weight upon arrival and higher levels of both CK and IgG were associated with a reduced hazard of morbidity. For mortality, higher weight upon arrival and higher levels of cholesterol and IgG were associated with a lower hazard of mortality occurring over the 78-d period of observation. Higher weight, cholesterol, copper, CK, iron, and IgG were associated with increased ADG, whereas increased zinc and haptoglobin were negatively associated with ADG. These results demonstrate that certain biomarkers could be used to identify high-risk calves when measured upon arrival at a veal facility. Future research should focus on determining the utility of these biomarkers to selectively target intervention strategies to improve ADG and reduce morbidity and mortality.

Perspectives on the Management of Surplus Dairy Calves in the United States and Canada

“…Given the multiple challenges from birth to arrival at calf-raisers (Figure 1), the first few weeks at the calf-raiser are a high-risk period. Over an 11 week period at a calf raiser in Ontario, 7.5% of calves died and almost 90% were treated with antimicrobials at least once for disease (27,40). Scott et al (27) and Renaud et al (2) also found 68% of calves were treated with antibiotics and 42% of calf deaths, respectively, occurred within the first 3 weeks after arrival to calf raisers.…”

“…Current antimicrobials use rates are influenced by high disease susceptibility and prevalent health abnormalities. For example, almost 90% of calves raised at a grain-fed veal facility in Ontario were treated with antimicrobials at least once during an 11week period (27,40). High rates of antimicrobial use has been associated with the development of antimicrobial resistance in commensal and pathogenic bacteria within the digestive and respiratory tract of veal calves (41,42) and increased carriage of antimicrobial resistant bacteria in calf caretakers (43).…”

“…There has been a significant body of literature assessing the utility of blood parameters in predicting future disease risk in veal calves. Many parameters, such as haptoglobin, creatinine kinase, and cholesterol (29,40,73), are likely not realistic to make a rapid assessment of calves arriving on farm due to a lack of the availability of calf-side tests. There are, however, potentially practical calf-side tests that are available to identify calves at high-risk of disease based on serum proteins.…”

“…There are, however, potentially practical calf-side tests that are available to identify calves at high-risk of disease based on serum proteins. For example, greater concentrations of immunoglobulin G (IgG) have been consistently associated with reduced disease occurrence in veal calves (29,40,75). On-farm IgG tests are becoming available which could allow for precise selection of calves with FTPI, however, the test performance has been variable when compared to radial immunodiffusion (3,76,77).…”

Calf and dam characteristics and calf transport age affect immunoglobulin titers and hematological parameters of veal calves

“…Recent observational studies have found associations between the background and rearing practices at the dairy farm of origin and mortality rate of calves at the veal farm (Winder et al, 2016;Renaud et al, 2018a). Correspondingly, BW and the clinical health condition of calves upon arrival at the veal farm (Renaud et al, 2018b;Scott et al, 2019) as well as biomarkers analyzed in a blood sample taken at arrival, including immunoglobulins (Pardon et al, 2015;Goetz et al, 2021), cholesterol (Renaud et al, 2018b), or specific immune cell counts (von Konigslow et al, 2020), were all significantly correlated with later risks of disease and mortality. Collectively, these studies suggest that both transport and husbandry characteristics at the dairy farm of origin may be important determinants of the biological state of a calf when it arrives at the veal farm.…”