Control diets, and diets containing 4% 1,3-butanediol (BD), 8% BD, 4% 1,2-propanediol (PD) and 8% PD were offered ad libitum to broilers from 1 to 28 days of age. Body weight gain and feed intake were recorded, and plasma metabolites and liver glycogen were measured. When compared to the control diet, the synthetic compounds depressed (p less than 0.01) growth at the 4% level, but the effect was more pronounced (p less than 0.01) at the 8% level. The test compounds had no effect (p less than 0.05) on the efficiency of feed utilization. Four percent BD elevated (p less than 0.01) plasma beta-hydroxybutyrate and acetoacetate concentrations, and the ratio of beta-hydroxybutyrate to acetoacetate. The influence was more pronounced at the 8% level; PD did not affect (p greater than or equal to 0.05) ketone body concentrations. Neither BD, nor PD caused changes (p greater than or equal to) in plasma glucose, free fatty acids, cholesterol, or liver glycogen. Results are discussed with reference to feeding these compounds to monogastric and ruminant animals.