An interaction between diet and blood group upon serum alkaline phosphatase activity in lambs.

Serum alkaline phosphatase activity was studied in groups of lambs fed diets containing different amounts of wheat grain and lucerne hay with different levels of supplementation with formaldehyde treated casein-sunflower seed. Total serum alkaline phosphatase activity increased more in groups fed 100 per cent wheat or 67 per cent wheat 33 per cent lucerne than in those fed 33 per cent wheat 67 per cent lucerne or 100 per cent lucerne. Supplementation of the diets with the casein-sunflower seed preparation resulted in an increase in the heat resistant proportion of serum alkaline phosphatase activity. This effect was more apparent in lambs of the r blood group (R-r-i blood group system) than in R lambs. These finds are discussed in relation to the relative heat resistance of tissue isoenzymes of alkaline phosphatase.