Tissue lipid fatty acid composition of biotin-adequate and biotin-deficient chicks.

Male broiler chicks were fed a purified ingredient diet containing various levels of added biotin to study dietary biotin effects on polyunsaturated fatty acids in selected tissues. Chicks were fed a basal diet containing adequate or deficient levels of added biotin and an additional group was fed a natural ingredient practical diet as a control. No significant differences in average body weights were found in chicks at 21 days fed 200 micrograms or more of biotin or the stock mash diet. Liver and heart biotin levels were lower in chicks fed less than 200 micrograms of biotin (P less than .01). At 21 days of age, the liver fatty acids of biotin-deficient chicks contained greatly (P less than .05) elevated c16:l, 18:ln9, 18:2n6, 18:3n6, and 18:3n3, whereas 20:3n6 and 20:4n6 were significantly lowered (P less than .05). Heart fatty acids c16:l and 18:2n6 of 21-day-old biotin-deficient chicks were elevated (P less than .05) and 18:3n3, 20:3n6, and 20:5n3 were lowered (P less than .05). It appears that the impaired conversion of 18:2n6 to 20:4n6 in liver tissue from biotin-deficient chicks at 3 weeks can result in lowered prostaglandin precursors not only in the liver but in the heart and muscle lipids as well. Changes in the brain and lung lipids are less marked.