Evaluation of blood metabolites reflects presence or absence of liver abscesses in beef cattle

Abstract

Liver abscesses constitute a prominent concern regarding animal health and profitability of the beef industry. Our objective was to evaluate potential biliary and blood indicators of liver abscesses. Twenty-nine beef bulls (initially averaging 356±70.5 kg and 253±30 days of age) were fed a high-concentrate diet during a performance test of 112 days, during which blood was collected at nine time points spaced 0.5-13 days apart within 56 days before slaughter. At the abattoir, blood and bile were collected and livers were inspected for liver abscesses. Results indicated that liver abscesses are associated with elevated levels of plasma cortisol and aspartate aminotransferase, and decreased levels of albumin, cholesterol and testosterone over the period before slaughter. Based on the blood samples collected during exsanguination, the presence of liver abscesses was associated with lower concentrations of thyroxine, albumin, cholesterol and alkaline phosphatase, and is suggested to be associated with lower blood carbon dioxide (P=0.08) and lower biliary cortisol metabolites (P=0.07). Albumin and cholesterol are established indicators of hepatic function and are consistently related to the presence of liver abscesses. Identifying blood parameters that predict liver abscesses has practical implications for cattle husbandry and for ensuring food safety.

Keywords: albumin; cholesterol; feedlot; high-grain diet; testosterone; thyroxine.

FIG 1

Results of mixed models showing the least square means of blood analytes. (a) Aspartate aminotransferase, (b) testosterone, (c) albumin and (d) cortisol for nine beef bulls with abscessed livers (…♦…) v20 bulls with normal livers (---□---) for each sampling time prior to slaughter (except for cortisol where the last sample immediately prior to slaughter was excluded). DB represents the average number of days (44+8) into the sampling period that corresponded with the day before slaughter. Differing subscripts represent P<0.05 overall the sampling period. The confidence limits for aspartate aminotransferase, testosterone, albumin and cortisol ranged from 54.29 to 70.58, 3.19 to 5.65, 29.24 to 32.73 and 30.08 to 55.02, respectively.