High dietary levels of magnesium (> 2 g/kg DM) have been implicated as the main causal factor of urinary calculi in concentrated-fed lambs. Two experiments were performed to test this belief.
Three pelleted Diets A, B and C, contained magnesium in- the following concentrations, A 2.9; B 8.6 ; C 2.9 g/kg DM. Calcined Magnesite was used as the source of extra magnesium in Diet B.
Diets A and B were each fed to twenty four Blackface lambs and the control group of 160 lambs was fed Diet C and ad lib hay. Details of diets and estimated mineral intakes are shown in tables 1 and 2.