Development of a simple enzyme immunoassay for blood haptoglobin concentration in cattle and its application in improving food safety.
OBJECTIVE
To verify the role of haptoglobin, a major acute-phase reactant protein in cattle, as a marker to identify health/disease status in cattle and further assess its potential in improving food safety.


METHODS
Serum samples from various cattle groups: clinically normal cattle comprising steers (n = 157) and culled dairy cows (n = 92) before death (antemortem [AM]); retained carcasses (n = 57) railed off the line during postmortem (PM) inspection; and apparently AM normal culled dairy cows (n = 57).


METHODS
Efficacy of the simplified monoclonal antibody-based enzyme immunoassay was established by comparing results of haptoglobin tests performed independently on aliquots of serum samples by 3 laboratories.


RESULTS
Haptoglobin concentration was significantly (P< or = 0.0001) different between the PM retained carcass group (n = 57) and the AM steer (n = 157) and culled dairy cow (n = 92) groups. In addition, haptoglobin concentration in AM steers (n = 157) and culled dairy cows (n = 92) was significantly (P < or = 0.0012) different, possibly reflecting a higher percentage of underlying pathologic or inflammatory conditions in animals of the latter group. Evaluation in 3 laboratories of sera from a group of culled dairy cows (n = 57), each laboratory performing a different test procedure, indicated that correlation of haptoglobin concentrations was good between the reported test procedure and the unmodified test and the classical hemoglobin-binding assay that measures peroxidase activity.


CONCLUSIONS
Haptoglobin determination is effective in identifying diseased and healthy cattle. It may be a potentially important tool for application at the farm and slaughterhouse as an aid in improving food safety.
Saini
P K
PK
Pathology and Serology Division, Food Safety and Inspection Service, US Department of Agriculture, Beltsville, MD 20705, USA.
Riaz
M
M
Webert
D W
DW
Eckersall
P D
PD
Young
C R
CR
Stanker
L H
LH
Chakrabarti
E
E
Judkins
J C
JC
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000175:diagnosis*; D005260:Female; D005506:Food Contamination / Q000517:prevention & control*; D006242:Haptoglobins / Q000032:analysis*; D007124:Immunoenzyme Techniques / Q000662:veterinary*; D008297:Male; D051379:Mice; D055095:Optics and Photonics; D012680:Sensitivity and Specificity; D012756:Sheep
D015415:Biomarkers; D006242:Haptoglobins