FOLIC-ACID REQUIREMENTS OF BROILERS

1. Dietary folic acid requirements of broilers were studied in three e xperiments using wheat- and maize-based practical diets. Requirements were assessed on the basis of performance and metabolic criteria. 2. G rowth and food conversion efficiencies were optimised with supplements of 1.5 mg folic acid/kg added to basal mash starter diets. The dietar y folic acid requirement of broilers was estimated to be in the range of 1.7 to 2.0 mg/kg.3. Red blood cell phosphoribosylpyrophosphate conc entrations and dihydrofolate reductase activites did not show consiste nt changes over the range of dietary folate concentrations studied but plasma folate concentrations responded markedly to dietary folate sup plementation. 4. Adding choline to diets in amounts greater than the n ormal requirement did not spare the requirement for folic acid. 5. It is suggested that minimum folic acid supplements for pelleted practica l diets should be in the order of 2.5 to 3 mg/kg.