Effect of journey and lairage time on physiological parameters of beef steers

ALENDE, M.; PIGHIN, D.G.; VOLPI LAGRECA, G.; GRIGIONI, G.; PAZOS, A.A.; PORDOMINGO, A.B.; BABINEC, F.; PORDOMINGO, A.J.

Mar del Plata

Congreso; 34 Congreso Argentino de Producción Animal-AAPA; 2011

Asociación Argentina de Producción Animal-AAPA

Transport to slaughterhouse is the most stressful event in cattle life. Additionally, it is not clear whether lairage allows cattle to recover from stress and reduce restlesness or not. The objective of this experience was to evaluate the effect of two journey times (JT) and two lairage times (LT) on physiological parameters related to stress, the plasmatic concentration of glucidic metabolites and hydration level. Sixty-four Angus stress (435,1 ± 20,76 kg live weight) were assigned to a 2x2 factorial arrangement consisting of two JT ( 3 h or 8 h) and two LT ( 2 h or 14 h). Animals were slaughtered in a comercial slaughterhouse, where blood and urine samples were obtained. Later, Longissimus dorsi samples were obtained within 45 minutes post-mortem, plunged into liquid nitrogen and stored at -80º C until analyzed. Packed cell volume (PCV) was measured in blood samples using the microhaematocrit technique. Total plasma protein (TPP) was measured in plasma samples by spectrophotmetry, glucose (GLU) and lactate (L) by enzymatic techniques. Muscle glycogen (MG) was assesed by acid hydrolisis. Adrenaline (A) and cortisol (C) were measured in urine samples by Elisa techique. Creatinine concentration was used to express hormones concentration in ng/ mg creatinine. Data were analyzed using proc GLM of SAS and Tukey test. There was not interaction between treatment factors. Journey time did not affect any of the variables (table 1) while longer LT increased PCV and TTP, decreased GLU concentration and tended to increase MG concentration. Steers assigned to shorter LT showed higher urinary concentration of A, while those assigned to longer LT showed higher concentration of C (Table 1). These results allow us to conclude that longer LT reduce the hydration level of animals (higher PCV and TPP), decrease plasmatic GLU concentration, but allow a slight recovery in MG concentration. Stress related hormones concentration (A and C) shows that lairage does not reduce restlessness because, despite a reduction in A concentration was found, there is an increase in C concentration.Longissimus dorsi samples were obtained within 45 minutes post-mortem, plunged into liquid nitrogen and stored at -80º C until analyzed. Packed cell volume (PCV) was measured in blood samples using the microhaematocrit technique. Total plasma protein (TPP) was measured in plasma samples by spectrophotmetry, glucose (GLU) and lactate (L) by enzymatic techniques. Muscle glycogen (MG) was assesed by acid hydrolisis. Adrenaline (A) and cortisol (C) were measured in urine samples by Elisa techique. Creatinine concentration was used to express hormones concentration in ng/ mg creatinine. Data were analyzed using proc GLM of SAS and Tukey test. There was not interaction between treatment factors. Journey time did not affect any of the variables (table 1) while longer LT increased PCV and TTP, decreased GLU concentration and tended to increase MG concentration. Steers assigned to shorter LT showed higher urinary concentration of A, while those assigned to longer LT showed higher concentration of C (Table 1). These results allow us to conclude that longer LT reduce the hydration level of animals (higher PCV and TPP), decrease plasmatic GLU concentration, but allow a slight recovery in MG concentration. Stress related hormones concentration (A and C) shows that lairage does not reduce restlessness because, despite a reduction in A concentration was found, there is an increase in C concentration.