Evening star. [volume] (Washington, D.C.) 1854-1972, 1912-08-17
NO MORE FOOD IN
YOLKS THAN IN WHITES
CoIoring Matter and Nutritive
Qualities in Hens Eggs.
Feed of Chickens.
From tho Literary Digest.

From tho Literary Digest
Is there any connection between the
color of an egg yolk and its nutrftive
qualities? The general popular impress
sion is that the darker yolks are the
richer, but there seems to be no exact ex-
detrimental evidence either for or against
this view Two recent opinions are quot
ed by the Revue Scientifque. Says this
paper:
Every one has noticed how the colora-
ton of the yolks varies from one egg
to another shading from very pale yellow
to reddish orange. The literature treat
ing of hens eggs is very large, yet few
writer's have been attracted by this ques-
ton of coloration Noticing. several years
ago. that the observed differences of
color arc without any effect on the In
trinsic qualities of the yok. which re-
mains equally nutritive and equally Vali-
able in reproduction. Morris attributed
the initial cause of the color to the ma
ture of the food.
Starting with the fact that it is paler
in winter and with hens living in un-
scientific quarters, he inferred from this
that the more intense colorauon of the
yolks of eggs laid by hens living at lib
erty was due to the colOring matter or
the green plants. and of the insects that
these fowls eat in large quantities. After
complex chemical Transportation these
pigments from the foodstutfs reach the
oyary whose fatty cells fix 1t. owing to
a special affinity - Consequently hens
should be placed in better conditions Of
life. by giving them spacious. grassy run
ways, and during the winter supplying
them, in the absence of fresh food, with
grain. salad. cabbage, beets and car
rots crushed or finely chopped"
This advice seems to be good. says the
reviewer. but why make an effort to give
the eggs colored yolks. II. as asserted.
these are no more nutritious than the
pale ones? The general impression. he
says, certainly is that the yellower yolks
are better, and this has been neither dis
proved nor proved. He goes on:
"Apropos of this question Of colora-
ton LAcclmatation February ID tells
us that. after repeated complaints from
their customers. certain associations OF
English breeders have drawn the atten-
ton of producers to the desirability OF OBJ
tanning yolks of higher color. and hence
more nutritive. by placing the hens in
proper conditions Of hygiene and nutrition.
and by giving them water having iron
in solution, twice week. This thesis,
which is very different, may be seen,
from that of Mr.. Morris. attributes to
the coloration Of the yolks an influence on
their nutritive power. and recognizes as
its cause their content in iron.
Neither Of these two opinions is based
on precise experiments. but both lead,
fortunately. to the same practical meas
ures. Giving healthful and abundant food
to hens, and placing them in sanitary
surroundings, Will assure them the
strength necessary to good layers; conse
quently. the egg. which is nothing else
but the totality of the alimentary reserves
placed at the disposal of the chick during
its embryonic life. should, logically be
more nutritive."