Effects of glycerol on the metabolism of broilers fed increasing glycerine levels

ABSTRACT

This study evaluated the metabolic response of broilers fed diets containing increasing crude glycerine levels in two bioassays. Birds were house in metabolic cages, and were distributed according to a completely randomized experimental design with five treatments of 4 replicates each (1st assay 5 birds/ cage; 2nd assay 1-20 days = 8 birds/ cage, and 21-42 days = 4 birds/cage). Treatments consisted of a control diet based on corn and soybean meal, and four other diets containing 2.5%, 5.0%, 7.5% and 10.0% glycerine derived from biodiesel. In experiment I, there was no effect (p>0.05) of glycerol level on liver weight or blood parameters. Serum blood glycerol levels of the birds fed 10% crude glycerine increased during the first nine days of diet intake (p 0.05). In experiment II, water intake increased (p 0.05) in the birds fed 7.5 and 10.0% crude glycerine at 4 and 8 days of age. Feed intake increased (p 0.05) on days 8 and 12 in birds fed 2.5 and 7.5% glycerine. Fecal moisture increased (p 0.05) in birds fed diets with 5.0, 7.5, and 10.0% crude glycerine on days 16 and 20. Ileal content moisture was not different (p>0.05) among treatments when birds were 42 days old. High dietary glycerine levels may induce metabolic change in broilers, such as increased blood glycerol level, water intake and fecal moisture.(AU)