No abstract

This study was designed to evaluate the influence of type of blood sample (serum or plasma) on essential and toxic element analysis in cattle. Paired plasma and serum samples (n = 20) were acid digested, and the concentrations of As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn. Mo, Ni, P, Pb, Sb, Se, Sr and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). The study findings indicate that plasma and serum samples appear suitable and interchangeable for the determination of most of the essential and toxic elements in blood in cattle. The only exceptions are Cu and Se, the concentrations of which were significantly lower (40.9 and 29.9% respectively) in serum than in plasma. Some of the Cu in blood samples from bovine ruminants is known to be sequestered during clotting. However, further research on Se in ruminants and other animal species is warranted. Finally, the significantly higher Mn (9.9%) concentrations in serum than in plasma may have been caused by haemolysis of some samples. Special attention should be paid to preventing haemolysis of samples during collection and processing, in order to prevent overestimation of elements present at high concentrations inside erythrocytes (i.e., Fe, Mn and Zn).

ABSTRACT. A six-month-old female Galician Blond beef calf presented signs of apathy, anorexia and weight loss. The analysis of a blood sample confirmed renal failure. Bilateral nephrolithiasis was diagnosed at necropsy. Quantitative analysis revealed the nephroliths to be composed of 100 per cent xanthine. In cattle, xanthinuria has only been described in the Japanese Black breed, but never before in other breeds. Clinical history suggested a naturally occurring xanthinuria.

Haemolysis of serum samples is the leading cause of preanalytical errors in clinical laboratories. Little is known about the potential alterations in the concentrations of mineral elements in haemolyzed serum and the phenomenon has not been specifically studied in bovine serum samples. We investigate how haemolysis affects the mineral content of bovine samples. We used ICP-MS to measure the concentrations of 12 mineral elements (Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Se and Zn) in bovine whole blood, serum and gradually haemolyzed samples and observed significant differences between the different types of samples, particularly in the Fe and Zn concentrations. However, in practice, the high interindividual variability makes it difficult to establish whether a given value corresponds to normal or haemolyzed samples. In response to this problem, we propose to consider that a result is significantly biased when the haemolysis threshold (the degree of haemolysis above which the concentration of an element in serum is significantly altered) of a given element is surpassed. The haemolysis threshold values for the different elements considered were found as follows: 0.015 g Hb L−1 for Fe, 2 g for Zn, 4 g for Cr and 8 g for Ca, Se and Mo.

A simple, rapid procedure is required for the routine detection and quantification of haemolysis, one of the main sources of unreliable results in serum analysis. In this study, we compared two different approaches for the rapid determination of haemolysis in cattle serum. The first consisted of estimating haemolysis via a simple direct ultraviolet–visible (UV–VIS) spectrophotometric measurement of serum samples. The second involved analysis of red, green, blue (RGB) colour data extracted from digital images of serum samples and relating the haemoglobin (Hb) content by means of both univariate (R, G, B and intensity separately) and multivariate calibrations (R, G, B and intensity jointly) using partial least squares regression and artificial neural networks. The direct UV–VIS analysis and RGB-multivariate analysis using neural network methods were both appropriate for evaluating haemolysis in serum cattle samples. The procedures displayed good accuracy (mean recoveries of 100.7 and 102.1%, respectively), adequate precision (with coefficients of variation from 0.21 to 2.68%), limit of detection (0.14 and 0.21 g L–1, respectively), and linearity of up to 10 g L–1.