Table 2. Fatty acid and triglyceride compositions of supplemented fat or oil to the experimental diets Table 1. Composition of experimental diet * Number of carbon atoms: number of double bonds, Br=branched chain acid ** tr=trace (bellow 0.1%) *** S=saturated and U=unsaturated acid 431

Table 3. Influences of dietary fat on the fatty acid compositions of egg yolk lipids (wt.%) * Egg yolk lipids from hens after 50 days on experimental diets ** TL=total lipid, NL=neutral lipid and PL=phospholipid

Table 4. The fatty acid distribution in triglycerides of fats and oils supplemented to the diets (Mole %) Table 5. Influences of dietary fat on the fatty acid distribution in triglycerides of egg yolk lipids (Mole %)

Table 6. Effects of dietary fat on the major component triglyceride contents of egg yolk (mole %) 4) EVANS, R. J., S. L. BANDEMER, and J. A. DAVIDSON Poultry Sci 46: 151-155. 1967. 5) MARION, J. E., and J. G. WOODROOF, Food Technol 22: 333-335. 1968. 6) HUSBANDS, D. R., Biochem J 120: 365-371. 1970. 7) CHRISTIE, W. W., and J. H. MOORE, Biochim Biophys Acta 218: 83-88. 1970. 8) PRIVETT, O. S., and L. J. NUTTER, Lipids 2: 149-154. 1967. 8) KUKSIS, A., and L. MARAI, Lipids 2: 217-224. 1967. 10) HOLUB, B. J., and A. KUKSIS, Lipids 4: 466-472. 1969. 11) COUCH, J. R., and A. E. SALOMA, Lipids 8: 675-681. 1973. * My=myristic, P=palmitic, Pt=palmitoleic, St=stearic, O=oleic, L=linoleic and Ln= 21) MURTY, N. L., and R. REISER, J Nutr 75: 287-294. 1961. 22) SIM, J. S., D. B. BRAGG, and G. C. HODGSON, Poultry Sci 52: 51-57. 1973. 23) MILLER, E. C., H. MENGE, and C. A. DEUTON, J Nutr 80: 431-440. 1963. 24) WHEELER, P., D. W. PETERSON, and G. D. MIlinolenic acid CHAELS, J Nutr 69: 253-260. 1959. 25) SELL, J. L., S. H. CHOO, and P. A. KONDRA, Poultry Sci 47: 1296-1302. 1968. 26) EVANS, R. J., J. A. DAVIDSON, J. N. LARUE, and L. BANDMER, Poultry Sci 42: 875-881. 1963. 27) CHUNG, R. A., E. Y. DAVIS, R. A. MONDAY, Y. C. TSAO, and A. MOORE, Poultry Sci 46: 133-141. 1967. 28) GUENTER, W., D. B. BRAGG, and P. A. KONDRA, Poultry Sci 50: 845-850. 1971. 29) EVANS, R. J., S. L. BANDEMER, and J. A. DAVID- SON, Poultry Sci 39: 1199-1203. 1960. 30) EVANS, R. J., J. A. DAVIDSON, and S. L. BANDE- MER, J Nutr 73: 282-290. 1961. 31) EVANS, R. J., D. H. BAUER, and C. J. FLEGEL, J Nutr 101: 355-362. 1971. 32) MACHLIN, L. J., and R. S. GORDON, Poultry Sci 41: 1340-1343. 1962. 438

Influences of Dietary Fat and Oil on the Fatty Acid Distribution in Egg Yolk Lipids of Laying Hens Yoshiyuki OHTAKE and Yasuzi HOSHINO Faculty of Agriculture, Utsunomiya University, Utsunomiya-shi 320 Laying hens were fed the diets supplemented with 10% of fat or oil (tallow, lard, soybean oil or cocount oil) for a period of 50 days, and the changes of fatty acid compositions of yolk lipids and the fatty acid distribution in yolk triglyceride affected by dietary fat and oil were studied. The feeding of diet supplemented with tallow or lard resulted the increase in C18:1 acid, the decrease in C16:0 and C18:2 acids in total lipids of egg yolk and the decrease in C20:4 and C22:5 acids in phospholipid of eggs. The feeding of soybean oil resulted the decrease in C16:0 and C18:1 acids and considerable increase in C18:2 acid in egg yolk lipids, and in phospholipid fraction of eggs, C22:5 decreased and C18:0 decreased on soybean oil feeding. The feeding of coconut oil resulted the increase in C14:0 and C16:1 acid and the decrease in C18:1 and C18:2 acids in total and neutral lipids of egg yolks, and on the other side, resulted the increased in C18:1 acid and the decrease in C20:4 and C22:5 acids in phospholipid of eggs. The fatty acid distribution in triglyceride was determined with the aid of pancreatic lipase hydrolysis. Although the fatty acid distribution in triglyceride of tallow was remarkably different from that of lard, not so much difference was observed between the yolk lipid from hens fed tallow and from hens fed lard on the fatty acid distribution in their triglycerides. The yolk lipid from hens fed soybean oil was considerably different with that from hens fed coconut oil on the fatty acid compositions of triglycerides, but in any case, C16:0 and C18:0 acids were found to be preferentially esterified at the 1,3-position in triglycerides and C18:2 acid predominantly linked at the 2-positions. The triglycerides in yolk lipids such as SUU and SUS tended to decrease and SSS, SSU and UUU increased on tallow feeding to hens. On lard feeding, SUS decreased and UUU increased in yolk lipids. The feeding of soybean oil resulted the considerable decrease in SUS and the increase in UUU in yolk lipids, and on the contrary, coconut oil feeding resulted the increase of SSS, SSU SUS and USU, and the decrease of SUU and UUU in yolk lipids. Concerning to the major component triglycerides in yolk lipids, PLP, PLO and OLO decreased and POO and OOO increased on tallow feeding to hens. On lard feeding, PLP and POPt decreased and OOO increased in egg lipids. The soybean oil feeding to hens resulted the decrease of POP, POSt POO and OOO in yolk lipids, and the distinct increase of PLP, POPt, StLO, PLL, OLO and OLL. On the other hand, coconut oil feeding resulted the decrease of PLP, POO, PLO, OOO and OLO, and the increase of MyOP and MyOO in yolk lipids. (Abbreviation used in this were as follow; S: saturated, U: unsaturated, P: palmitic, Pt: palmitoleic, St: stearic, O: oleic and L: linoleic acid). Jap. J. Zootech. Sci., 47, (7): 430-440. 440 1976. 7.