Assessment of Some Blood Parameters as Potential Markers of Hepatic Copper Accumulation in Cattle

Abstract

Abstract. The increasing frequency of copper (Cu) toxicosis episodes in cattle in recent years, mainly associated with excess Cu supplementation, underscores the need to identify animals in the clinically silent phase of hepatic Cu accumulation. The aim of the study reported here was to evaluate the suitability of various blood parameters as potential early markers of hepatic Cu accumulation in cattle. Paired liver and blood samples from 70 calves aged 6 to10 months were obtained at slaughter in a region in northwestern Spain where animals usually have hepatic Cu concentration higher than safe values. Neither serum Cu concentration nor ceruloplasmin (CP) concentration, the 2 parameters most commonly used for diagnosis of Cu deficiency, were significantly associated with hepatic Cu concentration. However, whole-blood Cu concentration had a slight but significant correlation with hepatic Cu concentration (r ϭ 0.269, P ϭ 0.026). The use of calculated blood parameters, such as the serum or whole-blood non-CP Cu fraction, or the CP-to-serum Cu ratio, increased the correlation with the hepatic Cu concentration (r ϭ 0.393, P ϭ 0.001, in the case of whole-blood, non-CP Cu concentration), but the strength of the association remained insufficient for accurate prediction of hepatic Cu values. Likewise, hepatic enzyme (aspartate transaminase and ␥-glutamyltransferase) activities were significantly or nearly correlated significantly with hepatic Cu concentration, but the strength of the association remained too low for accurate prediction. It is concluded that direct analysis of Cu concentration in liver biopsy specimens-preferably postmortem liver samples obtained at slaughter-is the best technique currently available for detecting chronic subclinical Cu accumulation in cattle at risk for supraoptimal Cu exposure.

Predictive Values of Aspartate Aminotransferase and Gamma-Glutamyl Transferase for the Hepatic Accumulation of Copper in Cattle and Buffalo

“…6,11 Consequently, several researchers have tried to establish parameters of clinical diagnosis based on laboratory analyses. 9,11,13 Serum Cu and other traditional biochemical variables have limited diagnostic value in terms of Cu accumulation, 9,13 and the best results were observed in sheep in association with alterations of hepatic enzymes. 7 Some researchers 13 have concluded that the most reliable factor in diagnosing early accumulation of Cu is determination of the serum activities of aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), not the determination of serum Cu concentration, acid phosphatase, and sorbitol dehydrogenase serum activities.…”

“…9 Additionally, glutamate dehydrogenase has elevated plasma activity even after the period of Cu overload and presents better results as an indicator of hepatic Cu accumulation than do AST and GGT in sheep. 7 However, because of their availability in Brazil and as a result of importation restrictions, these enzymatic evaluations were not performed as part of the current study.…”

Safety and efficacy of Mintrex®Cu (Copper chelate of hydroxy analogue of methionine) as feed additive for all species - Scientific Opinion of the Panel on Additives and Products or Substances used in Animal Feed

“…Liver copper is one of the best response criteria to assess the biological value of copper sources in monogastrics and ruminants (Jongbloed et al, 2002). A recent field study confirms that direct analysis of copper in the liver is the best biomarker of supraoptimal copper exposure (López-Alonso et al, 2006). Copper chaperone for copper/zinc superoxide dismutase is a sensitive biomarker for copper deficiency (Iskandar et al, 2005;Denzeisen et al, 2007).…”

Retrospective study of cattle poisonings in California: recognition, diagnosis, and treatment

“…Serum/plasma copper concentrations correlate poorly with liver copper concentrations. 69 However, in acute hemolytic crisis, serum copper concentration increases from the massive release of copper stores from the hepatocytes. Hepatic enzyme activity also increases.…”

“…The measurements are unlikely to be elevated prior to hemolytic crisis. 69 Thus, serum copper analysis can provide useful diagnostic data during the acute phase of the disease. Analysis is done routinely in laboratories using inductively coupled plasma emission spectrometry.…”