A comparison of acute phase protein measurements and meat inspection findings in cattle.

The acute phase proteins haptoglobin (Hp) and serum amyloid-A (SAA) are increased in the blood of cattle with infectious or inflammatory diseases. As it is important to identify such cattle at meat inspection, a study was undertaken to compare the levels of Hp and SAA in blood samples from cattle at abattoir with the post-mortem meat inspection findings. The serum concentrations of Hp and SAA were determined in healthy beef cattle (n = 16); healthy dairy cows with no pathological conditions (n = 22); and cows with pathologic conditions (n = 62). The last group was subdivided into cows with acute pathological conditions (n = 10) and those with non-acute pathological conditions (n = 52). The mean (+/-SD) Hp levels in plasma from beef cattle and cows without pathological conditions found were 0.11 +/- 0.08 mg/mL and 0.02 +/- 0.03 mg/mL, respectively, and the difference was statistically significant (p < 0.001). However, mean Hp level in cattle with pathological conditions was 0.27 +/- 0.40 mg/mL, significantly higher than the mean values of either group of healthy animals (p < 0.01 versus healthy dairy cows and p < 0.001 versus healthy beef cattle). The mean SAA concentration in plasma samples from 22 healthy dairy cows (with no pathological conditions found) was 51 +/- 38 microg/mL, significantly higher (p < 0.01) than the mean SAA value of 29 +/- 21 microg/mL calculated from 16 plasma samples from healthy beef cattle. In the group of 62 cows with pathological conditions, the mean SAA level was 94 +/- 115 microg/mL being significantly higher than the respective value in either groups of healthy animals (p < 0.01 versus healthy cows and p < 0.001 versus healthy beef cattle). Considerations of the acute phase proteins results obtained from the animals with pathological conditions did not reveal a clear association between acute phase proteins levels and respective specific pathological conditions, although there was a significant correlation between Hp and SAA concentrations at the individual animal level when all results were considered (R = 0.75, n = 100, p < 0.001). Nevertheless, when the dairy cows with pathological conditions were subdivided, some significant differences in mean values of acute phase proteins were observed enabling differentiation between animals with (broadly categorised) acute and non-acute pathological conditions. Significantly higher Hp (p < 0.05) and SAA (p < 0.05) concentrations were found in the acute pathology group than in the non-acute pathology group. Overall, the result of the present study indicated that the acute phase protein analysis could be an additional and useful tool enabling separation of "suspect" from "non-suspect" animals during ante mortem inspection within a modernised meat inspection system.