Effect of age at weaning on the physiological stress response and temperament of two beef cattle breeds

Abstract

The study was conducted to evaluate the effect of age at weaning and breed on the stress response of calves to weaning and their temperament. At calving, 14 Parda de Montañ a calves and 14 Pirenaica calves were randomly assigned to either early weaning (at 90 days) or traditional weaning (at 150 days) treatment. During nursing, calves were allowed to suckle their dams twice a day for 30 min. After weaning, calves were placed in an adjacent barn without access to their dams, where they remained for 7 days. On day 8 after weaning, they were transported to a feedlot where they received an intensive diet. Blood samples were taken 168 h before weaning (baseline) and 6, 24, 48 and 168 h after weaning for cortisol, fibrinogen and haematology analyses, and temperament was measured 90 and 180 days after weaning with the flight speed test. Cortisol concentration increased after weaning, irrespective of age at weaning. Early-weaned calves had a lower fibrinogen baseline and a greater increase in fibrinogen concentrations 48 h after weaning than traditionally weaned calves. Moreover, fibrinogen concentration returned to baseline values 168 h after weaning in traditionally weaned calves, whereas it remained high in early-weaned calves. Concerning breed effects, Pirenaica calves had higher cortisol concentration and fibrinogen increments after weaning than Parda de Montañ a calves. Slight alterations occurred after weaning in haematology, but all parameters returned to baseline values 168 h after weaning, with no significant effects of age at weaning or breed. Despite the absence of clinical signs, early-weaned calves of both breeds suffered marginal anaemia, according to haemoglobin values. Regardless of age at weaning, Pirenaica calves had greater reactivity to human presence than Parda de Montañ a calves, according to their higher flight speed values measured. Finally, early-weaned calves were lighter than traditionally weaned calves at weaning, but had similar weight gains in the feedlot. Consequently, they needed an additional 40 days to reach the target weight, irrespective of breed. Therefore, age at weaning had no major effects on the stress response to weaning or temperament, but early weaning increased the length of the feedlot period. On the other hand, Pirenaica calves were more reactive than Parda de Montañ a calves to the stress of weaning and human presence.

Effects of castration and weaning conducted concurrently or consecutively on behaviour, blood traits and performance in beef calves

“…The course of the neutrophil : lymphocyte ratio did not show different changes during the study period between castration and weaning groups, too. Blanco et al (2009) weaned calves at 90 or 150 days of age and also did not find an effect of weaning on neutrophil or lymphocyte proportions until 1 week after weaning. A contrary observation was made by Hickey et al (2003), who found decreased lymphocyte and increased neutrophil proportions as well as increased neutrophil : lymphocyte ratios in weaned compared with control calves until 1 week after the treatment.…”

Biomarker responses to weaning stress in beef calves

“…In the present study, a number of alterations to the blood leukogram were identified. Weaning and housing have both been previously shown to increase total leukocyte number (Blanco et al, 2009;Hickey et al, 2003b;Lynch et al, 2010) as a result of fluctuations in a number of leukocyte subpopulations, particularly neutrophils. Elevations in endogenous or exogenous glucocorticoids are reported to cause a dramatic shift in the haematological profile of peripheral blood cells resulting in leukocytosis which is marked by neutrophilia and lymphopenia (Burton et al, 2005).…”

“…Although some studies have shown that this response is activated through the measurement of fibrinogen, ceruloplasmin and SAA (Arthington et al, 2003(Arthington et al, , 2008Blanco et al, 2009;Carroll et al, 2009), others have reported that concentrations of fibrinogen and haptoglobin are not affected by weaning (Hickey et al, 2003b).…”

“…Neutrophilia is one of the most frequently reported biomarkers of stress in cattle following weaning (Blanco et al, 2009;Lynch et al, 2011Lynch et al, , 2012O'Loughlin et al, 2011O'Loughlin et al, , 2012 and housing (Gupta et al, 2007;Hickey et al, 2003a). Gene expression of the potent neutrophil chemokine, CXCL8, was found to be up-regulated following transport (20-fold increase) (Gupta et al, 2007), castration (2-fold increase) (Pang et al, 2009) and weaning (2-fold increase) (O'Loughlin et al, 2011) and may account for distributional alterations in circulating neutrophils, serving to increase immune surveillance (Jones and Allison, 2007).…”

Minimizing cows’ stress when calves were early weaned using the two-step method with nose flaps

“…Weaning elicits a stress response in both cows (Lefcourt and Elsasser, 1995;Haley, 2006;Lynch et al, 2010a) and calves (Blanco et al, 2009;Lynch et al, 2010b and, thus reducing their welfare. For example, cows begin pacing and vocalizing immediately after their calves are weaned, showing that it is a stressful event for them 2015).…”