ICTERUS IN BOB VEAL CALVES AND ITS ASSOCIATION WITH LACK OF COLOSTRUMINTAKE AND HIGH SERUM CREATINE-KINASE ACTIVITY

Icterus condemnations compose a substantial proportion (41%) of total condemnations of bob veal, the class of veal composed of calves < 3 we eks old and weighing up to 68 kg. At postmortem examination, bob veal condemned because of icterus have generalized yellow discoloration of tissues, which is commonly associated with large, yellow liver (fatty liver), and a paucity of other gross pathologic changes. To establish that the generalized yellow discoloration was attributable to high tis sue bilirubin concentrations and to examine the underlying mechanism(s ) that might be responsible, blood samples and tissue specimens were o btained from clinically normal and icteric bob veal calves at slaughte r. For comparison, blood samples were collected from clinically normal , 1- to 5-day-old Holstein calves being raised on local dairy farms. H ematologic and serum biochemical analyses were obtained for the 3 grou ps of calves (normal local, normal slaughter, and icteric slaughter), and tissues of slaughter calves were examined for histologic evidence of inflammatory or degenerative changes. Mean +/- so total bilirubin c oncentration and creatine kinase (CK) activity in icteric bob veal (3. 3 +/- 0.8 mg/dl; 869 +/- 788 U/L), normal bob veal (1.4 +/- 0.7 mg/dl; 486 +/- 890 U/L), and normal local calves (0.5 +/- 0.2 mg/dl; 156 +/- 158 U/L) were significantly different. When data for both normal and icteric bob veal calf groups were combined for analysis, total bilirub in concentration regressed significantly on hepatic lipid scores (P = 0.00003) and CK activity (P = 0.00049). Colostrum consumption was dete rmined by measuring serum total protein concentration and serum gamma- glutamyltransferase activity. Bob veal calves that had not consumed co lostrum had significantly higher total bilirubin (P = 0.00005) and CK (P = 0.0008) values. It was concluded that normal and icteric bob veal calves have significant increase in total bilirubin concentration, an d icterus of bob veal calves is secondary to unconjugated hyperbilirub inemia. Lack of colostrum consumption was strongly correlated with ict erus in bob veal calves.