The effect of animal handling procedures on the blood non-esterified fatty acid and glucose concentrations of lactating dairy cows

Blood glucose and non-esterified fatty acid (NEFA) concentrations (often determined in cows to evaluate their energy status) can be influenced by stress. To assess whether the stress of routine handling prior to blood-sampling might influence the systemic concentrations of these compounds, blood samples were taken from two groups of lactating dairy cows and one group was subjected to routine handling procedures at 11 and 46 days post-partum (pp). The results were analysed using a linear mixed-effect model. The NEFA and glucose concentrations were significantly increased in the animals that had been handled when compared to the controls. The fatty acid composition of the NEFA fraction was altered at 46 days pp in the animals that had been handled prior to sampling. The findings suggest that handling lactating cows prior to blood-sampling should be minimised in order to reduce the effect on blood glucose and NEFA concentrations and possible consequent misinterpretation of the animals' energy status. (C) 2009 Elsevier Ltd. All rights reserved.