Document type: scientific article published in Italian Journal of Animal Science
Authors: E. Romera-Recio, D.R. Yáñez-Ruiz, A. Belanche, N. Llanes, J. Torra, and E. Ramos-Morales
Abstract in French (translation): Physiological responses of male dairy calves to long-distance transport during the weaning period
This observational study characterized the reactions of unweaned male dairy calves during a single 12-hour trip (750 km) under standard commercial conditions. Sixty-six Montbéliarde calves (aged 21 ± 7 days) had samples collected before loading at a gathering center and again upon arrival at the breeding farm. The calves were given a glucose- and electrolyte-based rehydration solution two hours before loading and had access to water during a rest stop. Biochemical and hematological blood tests were performed to characterize changes in energy metabolism, water and electrolyte balance, circulating proteins, and hematological parameters. Transport was associated with significant changes in several physiological parameters. Glucose levels decreased significantly, while nonesterified fatty acids and beta-hydroxybutyrate remained unchanged. Immunoglobulin G concentrations increased, while haptoglobin concentrations decreased between sampling points. Urea and sodium concentrations decreased, while potassium concentrations and hematocrit increased slightly. Slight increases were also observed in liver biomarkers, while creatine kinase and lactate dehydrogenase remained unchanged. Transport was also associated with a decrease in platelet, white blood cell, and neutrophil counts. However, several biomarkers were already outside the reference ranges reported at the collection point at the gathering center, suggesting that the calves may have been loaded for transport in an altered physiological state. This underscores the importance of pre-transport management conditions when evaluating the physiological response of calves during commercial transport.
Preview:
This observational study characterised the responses of unweaned male dairy calves to a single 12 h (750 km) journey under routine commercial conditions. Sixty-six Montbéliarde calves (21 ± 7 days old) were sampled before loading at an assembly centre and upon arrival at the rearing farm. Calves received a glucose-electrolyte hydration solution 2 h before loading and had access to water during a rest stop. Blood biochemistry and haematology were analysed to characterise changes in energy metabolism, fluid and electrolyte balance, circulating proteins and haematological variables. Transport was associated with significant changes in several physiological parameters. Glucose decreased significantly, whereas non-esterified fatty acids and beta-hydroxybutyrate remained unchanged. Immunoglobulin G concentrations increased, while haptoglobin concentrations decreased between sampling points. Urea and sodium concentrations decreased, whereas potassium and haematocrit increased slightly. Mild increases were also observed in hepatic biomarkers, while creatine kinase and lactate dehydrogenase remained unchanged. Transport was further associated with reductions in platelet, leukocyte and neutrophil counts. However, several biomarkers were already outside reported reference ranges at the assembly centre sampling point, suggesting that calves may have entered transport in an altered physiological state. This highlights the importance of pre-transport management conditions when assessing calf physiological response during commercial transport.
