RELATIONSHIPS BETWEEN LIVER ELEMENT CONCENTRATIONS AND AGE IN PERINATAL LAMBS DYING OF NATURAL CAUSES IN MICHIGAN, USA

A study was designed to characterize potential relationships between l iver concentration of nine specific elements and age in preweaned Mich igan lambs. All lambs that died before weaning in 1986 from 33 Michiga n sheep producers were submitted to the Michigan State University Anim al Health Diagnostic Laboratory for necropsy. Inductively coupled argo n plasma emission spectroscopy was used to measure liver concentration s of Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn in 888 lambs. Linear and non -linear regression techniques were employed to evaluate the relationsh ip between liver element concentration and age. The potentially confou nding variables farm of origin and cause of death were significant (P< 0.01) in all models. No linear relationship was found between any live r element concentration and lamb age. Significant (P<0.05) non-linear relationships were found between liver concentrations of Cu, Fe, K, Na , Mg, and Zn and lamb age. Because of the large sample size of lambs s elected from non-experimental populations, these results should provid e diagnosticians with a useful guide for the interpretation of similar data when investigating perinatal lamb mortality.