G. M. Briggs

Essential Fatty Acids in the Chick. I. Development of Fat Deficiency.

Summary Day-old chicks raised on a purified diet containing approximately 0.046% fat grew normally for 6-8 weeks, at which time weight gains began to decrease slightly. No marked symptoms of deficiency developed, but depigmentation of feathers and scaliness of skin were observed. Fat-deficient male chicks had smaller testes and some females had immature oviducts, when compared with normal chicks. Water consumption by the deficient birds did not increase markedly until the 11th week on the fat-free diet.

Comparison of vitamin B12 and desdimethyl B12 activity in the chick.

Summary Desdimethyl B12 had only approximately 9% of the activity of vit. B12 in stimulating growth of chicks fed a vit. B12-low, corn-soybean diet containing 20% of lard.

Activity of certain vit. B12 analogues in the chick.

Summary Activity of various vit. B12 analogues was determined in young chicks fed a corn-soybean oil meal diet high in fat. The presence of cyanide in the molecule is not necessary for full vit. B12 activity in the chick since acetato-, chloro-, nitro-, and sulfatoco-balamin had activities equal to that of vit. B12 when fed or injected. Factor B had no vit. B12-like activity nor any antagonistic action. The 5-hydroxy analogue of vit. B12 had about one-tenth to one-third of the activity of vit. B12.

Effect of Diets High in Fat or Protein on Vitamin B12 Deficiency in Non-depleted Chick

Summary A severe vit. B12 deficiency, as indicated by poor growth, was produced by dietary means in non-depleted chicks. Replacing 20% of the corn in an all-vegetable corn-soybean oil meal diet with 20% fat increased the weight difference between chicks receiving vit. B12 and the unsupplemented birds. A less striking effect was obtained with 20% vegetable protein.