A. Ginzberg et al., Chickens fed with biomass of the red microalga Porphyridium sp have reduced blood cholesterol level and modified fatty acid composition in egg yolk, J APPL PHYC, 12(3-5), 2000, pp. 325-330
The biomass of the red alga Porphyridium sp. constitutes a unique combinati
on of soluble sulfated polysaccharide that accounts for about 70% of the al
gal dry weight, and various polyunsaturated fatty acids (PUFA) such as arac
hidonic and eicosapentaenoic acid (AA, 20:4 omega6 and EPA, 20:5 omega3). I
n view of earlier results in our laboratory showing a reduction in serum ch
olesterol and triglyceride levels in rodents fed with red algal biomass, we
set out to examine the influence of algal biomass as a feed additive on th
e metabolism of chickens, with an emphasis on blood and egg cholesterol lev
els. For that purpose, lyophilized algal biomass was fed to 12-13, 30-week-
old, White Leghorn chickens for 10 days at a proportion of 5% or 10% of the
standard chicken diet. Twelve chickens fed with unsupplemented diet served
as the control. No differences in body weight, egg number, and egg weight
were found between the algal-fed chickens (at both concentrations) and the
control. However, chickens fed with algal biomass consumed 10% less food fo
r both groups, and their serum cholesterol levels were significantly lower
(by 11% and 28% for the groups fed with 5% and 10% supplement, respectively
) as compared with the respective values of the control group. Egg yolk of
chickens fed with algae tended to have reduced cholesterol levels (by 10%)
and increased linoleic acid and arachidonic acid levels (by 29% and 24%, re
spectively). In addition, the color of the egg yolk was darker as a result
of the higher carotenoid levels (2.4 fold higher) for chickens that fed wit
h 5% supplement. These results encourage the development of an improved chi
cken feed having dietary fibers and polyunsaturated fatty acids.