St. Ding et Ms. Lilburn, CHANGES IN FATTY-ACID PROFILES IN DIFFERENT LIPID CLASSES DURING LATEDEVELOPMENT OF TURKEY EMBRYOS FROM 2 GENETIC LINES, Poultry science, 76(6), 1997, pp. 828-833
Fatty acid (FA) profiles in embryonic yolk sacs (YS) and livers were s
tudied in embryos from a randombred turkey Line (RBC2) and a line sele
cted for body weight at 16 wk (F line). There were no differences in F
A profiles of fresh yolk lipids. During the course of incubation, olei
c acid (C-18:1) was higher and linoleic acid (C-18:2) was lower in YS
triglyceride (TG) and phospholipid (PL) subclasses in F line compared
with RBC2 embryos. In both lines, the C-18:1 content of YS cholesteryl
esters (CE) increased from 58 to 63% during the last 6 d of incubatio
n. From 22 to 28 d of incubation, there was a constant C-18:1 concentr
ation in hepatic CE, which was > 60% of total hepatic CE FA. As incuba
tion proceeded, palmitic acid (C-16:0) and C-18:1 in hepatic TG decrea
sed from 27 to 16% and 37 to 34%, respectively. The stearic acid (C-18
:0) in TG increased from 12% at Day 22 to 32% of total FA at hatch (Da
y 28) in RBC2 embryos compared with a lesser increase in the F line (1
1.8 to 18.6%). In hepatic FL, arachidonic acid (C-20:4) decreased, whe
reas both C-16:0 and C-18:0 increased from 22 to 28 d of incubation. D
uring this same time period, there was an overall decline in docosahex
aenoic acid (C-22:6) only in the RBC2. On Days 26 and 28, F line embry
os had greater concentrations of C-22:6 and C-20:4 in hepatic PL than
did RBC2. These results suggest that selection for increased BW has ch
anged the proportional incorporation of different FA into embryonic li
pids.