802 XIII. ESSENTIAL FATTY ACIDS 



observed in the hog because the tissue hnoleate is sufficient to protect the 

 animal on a fat-free diet for an extended period. It is also possible that 

 swine synthesize more linoleic acid than do other species. On the other 

 hand, Witz and Beeson"® described a fatty acid deficiency in the pig. 



Definite evidence of tlie role of the EFA in calves has only recently become 

 available. In fact, Gullickson et al}^"^ were unable to demonstrate that 

 essential fatty acids Avere required by calves; when vegetable oils were 

 homogenized into skimmed milk, the resulting product could not be toler- 

 ated by the calves. Most of the animals did poorly, and a number of them 

 died, in contradistinction to the relatively satisfactory results when whole 

 milk was used. Although Gullickson and co-workers"^ indicated more 

 recently that the replacement of butterfat with vegetable oils caused some 

 symptoms characteristic of vitamin E deficiency, they have likewise reported 

 the normal development of a calf maintained for over forty-five days on a 

 skim-milk diet into which partially hydrogenated vegetable oil was homog- 

 enized. It has also been impossible to produce fat deficiency in cows, 

 according to Gibson and Huffman,"^ and Maynard et al.,^^^ although a 

 decrease in the iodine value of the blood lipids was shown to occur when the 

 animals were continued on a fat-free diet o\er a prolonged period. The 

 recent studies of Lambert et al.^-^ have left no doubt that the calf is suscep- 

 tible to EFA deficienc3^ Thus, these workers observed a marked retarda- 

 tion of growth of 50% in the case of calves on a fat-deficient regimen. Scaly 

 dandruff was also noted, together with an excessive loss of hair on the back, 

 shoulders, and tail. These characteristic symptoms of fat deficiency were 

 promptly alleviated when sources of the EP^'A were administered. 



The dog represents a species which is readily susceptible to the fat- 

 deficiency sjaidrome. Because of the convenient size of this species, which 

 will enable a clinical study to be made on one animal over a period of time, 

 considerable work has been reported on EFA deficiency in these animals. 

 Hansen and Wiese^-^ demonstrated, in 1943, that the symptoms of fat 



"6 W. M. Witz and W. M. Beeson, J. Animal Set., 10, 112-128 (1951). 



"^T. W. Gullickson, F. C. Fountaine, and J. B. Fitch, J. Dairy Sci., 24A, 315-316 

 (1941). 



"8T. W. Gullickson, R. S. Adams, J. Gander, and J. H. Sautter, /. Dairy Sci., 36, 

 599-600(1953). 



"8 G. Gibson and C. F. Huffman, Michigan State Coll., Agr., Appl. Sci., Agr. Exptl. 

 Sta. Quart. Bull., 21, 258-264 (1939). 



1^ L. A. Maynard, K. E. Gardner, and A. Hodson, New York {Cornell Univ.) Agr. 

 Exptl. Sta. Bull. No. 722 (March 10, 1939), pp. 1-30. 



1" M. R. Lambert, N. L. Jacobson, R. S. Allen, and J. H. Zaletel, /. Nutrition, 52, 

 259-272(1954). 



122 A. E. Hansen and H. F. Wiese, Proc. Soc. Exptl. Biol. Med., 52, 205-208 (1943). 



