Reference values for serum amyloid A, haptoglobin, lysozyme, zinc and iron in healthy lactating Lacaune sheep

Acute-phase proteins and trace elements are considered biomarkers of the immune response to infection, inflammation, trauma and other pathological conditions, as well as indicators of the health status and productivity of farm animals. Given the scarcity of published data on this topic, the purpose of this study was to determine the serum levels of serum amyloid A (SAA) and haptoglobin, as well as lysozyme, iron and zinc in clinically healthy Lacaune sheep in lactation months 3–7 ranging in age from 2 to 6 years. The mean serum levels for SAA (12.2 µg/mL), lysozyme (1.47 µg/mL), zinc (78.9 µg/dL) and iron (26.6 mmol/L) differed from those found in other sheep breeds and indicate considerable variations depending on breed, age and physiological status of the sheep. Reference values for clinically healthy mid-lactating Lacaune sheep were determined by using well-described and modern analytical and statistical methods. The reference intervals may be used to determine the health and welfare of lactating Lacaune sheep and may serve as a starting point to investigate diseases.