Clinical and metabolic indicators associated with early mortality at a milk-fed veal facility: A prospective case-control study

Abstract

Antimicrobial use and resistance, in combination with high levels of mortality, are important challenges facing the veal industry. To improve both the economic sustainability of the industry and animal welfare, measures need to be taken to explore and address reasons for these challenges. Health status at arrival may be an important predictor of calf mortality because substantial mortality occurs early in the growing period on veal operations. The objective of this observational case-control study was to identify clinically measurable variables and metabolic indicators associated with mortality in the first 21 d following arrival at a veal facility. Calves were evaluated using a standardized health scoring system, blood was collected, calves were weighed, and the supplier of the calf was recorded at arrival. The calves were followed until death or 21 d after arrival. Cases were defined as calves that died ≤21 d following arrival. Two controls for every case were randomly selected from calves that survived >21 d, arrived on the same day, and were housed in the same barn as cases. Stored serum harvested at arrival from cases and controls was submitted for measurement of concentrations of nonesterified fatty acids, β-hydroxybutyrate, glucose, cholesterol, urea, haptoglobin, and immunoglobulin G. A conditional logistic regression model was built to evaluate factors associated with mortality ≤21 d following arrival. A total of 4,825 calves were evaluated from November 2015 to September 2016. The mortality risk in the first 21 d was 2.8%, giving 135 cases, which were compared with 270 controls. Six variables were significant in the final multivariable model. Calves with a slightly enlarged navel with slight pain or moisture, and those with severe dehydration had increased odds of mortality ≤21 d following arrival. Drover-derived calves, calves that weighed more, and calves that had higher concentration of immunoglobulin G or cholesterol at arrival were less likely to die. The results demonstrate that calves at elevated risk for early mortality can be identified at arrival using both health and hematological factors. Early recognition of high-risk calves may allow for an intervention that could result in improvement in survival rates; however, prevention of these abnormalities before arrival at veal facilities needs to be further explored.

Biosecurity practices in Belgian veal calf farming: Level of implementation, attitudes, strengths, weaknesses and constraints

“…Furthermore, a higher serum IgG concentration decreased the risk of mortality, according to Renaud et al (2018). A concentration of less than 7.5 g/L IgG was shown to decrease average daily gain (Pardon et al, 2015).…”

Randomized field trial on the effects of body weight and short transport on stress and immune variables in 2‐ to 4‐week‐old dairy calves

“…Next to transport stress, body weight apparently influences disease susceptibility of preweaned calves. Underconditioned or so‐called “underweight” calves are at an increased disease and death risk . Veal calves weighing <43 kg at arrival at 2‐4 weeks of age had a higher risk for BRD at the early stage of fattening .…”

“…Underconditioned or socalled "underweight" calves are at an increased disease and death risk. 25 Veal calves weighing <43 kg at arrival at 2-4 weeks of age had a higher risk for BRD at the early stage of fattening. 26 This association is probably due to a poorer energy or immunological status impairing the calves' ability to cope with their new environment (housing, climate and feed) and multiple stressors (mixing of unfamiliar animals, handling, transport, restraint, and crowding).…”

Short communication: Validation of methods for practically evaluating failed passive transfer of immunity in calves arriving at a veal facility

“…Providing a sufficient quantity of high-quality colostrum to newborn calves is an integral component of calf management because failed passive transfer of immunity (FPT) in calves is associated with an increased risk of disease (Postema and Mol, 1984;Godden, 2008;Pardon et al, 2015) and mortality (Renaud et al, 2018). Despite the known importance of feeding colostrum, FPT is estimated to be common among calves entering the veal industry (Wilson et al, 2000;Pardon et al, 2015).…”

“…Radial immunodiffusion (RID) is the gold standard method for determining passive transfer of immunity (Beam et al, 2009); however, blood must be sent to a referral laboratory for this technique to be performed. Serum total protein (STP) determined by refractometry has been shown to be well correlated with immunoglobulin concentrations measured by RID in dairy calves (Naylor and Kronfeld, 1977), but it has not been validated in calves upon arrival at veal facilities, where the age of the calves is unknown and many calves are dehydrated (Renaud et al, 2018). A new semiquantitative antibody test (ZAP test) has been validated using serum from dairy calves; however, it has not been used on whole blood (Elsohaby and Keefe, 2015).…”