Interrelationships among growth, endocrine, immune, and temperament variables in neonatal Brahman calves

Abstract

Interrelationships among growth, endocrine, immune, and temperament variables were assessed in neonatal Brahman calves. The velocity upon exiting a working chute (exit velocity) of an animal was measured and used as an objective indicator of temperament to classify calves as calm, intermediate, or temperamental. Calves (n = 116) were weighed weekly between d 0 and 21 to 24, and blood samples were collected for plasma and serum on d 0, 1, 2, 7, 14, and 21 to 24 after birth to measure concentrations of immunoglobulins, cortisol, and epinephrine (EPI). Body weight increased from d 0 through d 21 to 24 (P < 0.001) with bulls (n = 60) having greater BW than heifers (n = 56; P = 0.02). Serum concentrations of cortisol were greatest on d 0 before declining (P < 0.001) over the ensuing 21 to 24 d and were not related to temperament (P = 0.89) or sex (P = 0.97). Concentrations of EPI were affected by time, with an increase in EPI concentrations in temperamental bulls between 2 and 14 d of age (P < 0.008). Concentrations of EPI were not affected by temperament (P = 0.44) or sex (P = 0.68). Serum immunoglobulin concentrations peaked on d 1 before declining (P < 0.01) but were not related to temperament (P = 0.40 to 0.68). Of the stress hormones measured (cortisol and EPI), only cortisol was associated with the early performance of the calf. Calf BW at d 21 to 24 and BW gain were positively associated with serum immunoglobulin concentrations, yet negatively associated with concentrations of cortisol. Serum immunoglobulin concentrations were negatively correlated with cortisol concentrations (r = -0.28; P = 0.003), yet positively associated with EPI concentrations (r = 0.51; P = 0.003). During the neonatal period in this study, there was no relationship of temperament with passive immunity or stress hormone concentrations; however, growth was positively associated with passive immunity and negatively associated with stress hormones. Measuring exit velocity as early in life as d 21 to 24 fails to accurately predict temperament at weaning in over 40% of Brahman calves. Our conclusion is that measurement of exit velocity should be done nearer to the time of weaning than to birth. These data can be beneficial in developing best management practices for young calves.

Temperament influences endotoxin-induced changes in rectal temperature, sickness behavior, and plasma epinephrine concentrations in bulls

“…27 The minimum detectable cortisol concentration was 1.2 ng/ml and the intraand interassay coefficients of variance were 4.3% and 2.4%, respectively. Serum concentrations of cortisol were determined by comparison to a standard curve generated with known concentrations of cortisol and presented as the concentration in nanogram per millilitre.…”

“…27 Data are presented as picogram per millilitre. The minimum detectable epinephrine concentration was 11 pg/ml and the intra-and interassay coefficients of variation were 3.7% and 7.4%, respectively.…”

Relationships between temperament and transportation with rectal temperature and serum concentrations of cortisol and epinephrine in bulls

“…Serum concentrations of cortisol were determined using a single antibody radioimmunoassay (DSL-2100; Diagnostic Systems Labs, Webster, TX) utilizing rabbit anti-cortisol antiserum coated tubes according to the manufacturer's directions (Burdick et al, 2009). The minimum detectable cortisol concentration was 1.2 ng/mL and the intra-and interassay coefficients of variation were 4.3% and 2.4%, respectively.…”

“…Plasma concentrations of epinephrine were determined by enzyme immunoassay according to the manufacturer's directions (17-BCTHU-E02; Alpco Diagnostics, Boston, MA; Burdick et al, 2009) by comparison of unknowns to standard curves generated with known concentrations of epinephrine. Data are presented as pg/mL.…”

A balanced perspective on animal welfare for improved meat and meat products

“…Stressful conditions lead to elevated plasma cortisol concentrations, which may also be related to PSE meat, especially in pigs (Chai et al, 2010). In calves, temperament and excitability were assessed and it was reported that cortisol and catecholamines are produced when calves experience acute stress during weaning (Burdick et al, 2009;O'Neill et al 2010). In human beings, cortisol levels are reported to have increased owing to related abnormal behaviour (Haller et al, 2005) whereas in animals they were related to aggressive and antagonistic behaviour (Reisnet et al, 2007).…”