Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1912-11-15
Agricultural Help
HOW MANY EGGS CAN A GOOD
HEN LAY?
interesting Discussion by Maine Elk
pertinent Station Biologist.

| finished product-is the result of long
| and complicated series of physiological
| processes. 1t begins as a microscopic
| cell in the body of the embryo chick
| many days before Matching. Indeed, at
the time when the poultryman makes the
| first test egg in his incubator, all the
eggs which will be laid by the pullet that
| will hatch from one of the fertile eggs
/ which passes through his hands are al
| ready present in the embryo chick as
| definite and distinct bodies. As develop
ment proceeds these embryonic eggs, or
| oocytes, are collected together in a de-
| finite organ of the body, the oVafy, or
| "egg-cluster.' During the growth of
| the chick these oocytes develop. they
increase in size, chiefly by the deposition
of yolk within them, The surface of the
ovary becomes studded with little
| spheres, first very small, but all the
| time growing. When the pullet reaches
| the age of about six months. If all mas
gone we'll with it physiologically, certain
ones of the ooeytes begin a very rapid
growth-much more rapid than that
| which had preceded. a relatively thick
layer of yolk is added each. day, and
presently an egg is laid.
when the oocyte has attained that re-
spectability of size which entities 1t to
be called in common parlance ''yolk, .
the thin membranous funnel end OF the
oviduct, or egg tube" slowly and care
fully wraps around it, and encioses it
within the cavity of the tube. Shortly
the sac of membrane which has held
the developing yolk ruptures along Il
definite line, and the completed yolk es-
capes from the bonds which have held
it during the long months OF its growth,
and drops free into the egg-tube. which
has been wrapped around TO receive it.
The freed yolk now passes slowly
down the egg-tube, and receives on its
way its protecting layers of white" or
albumen, the shell membrane and the
shell itself. At the end of the process
the finished product, an egg, as we know
II in everyday life, passes outside of
the body of the hen, to begin its check
cred course to the breakfast-table OF the
consumer.
Now, from the standpoint of the poul-
try-man the most interesting point IN
this long chain of events is that at
separated from the ovary. The frequen-
Tor, as it is technically called, ovuiation)
occurs within the lifetime of the bird
measures its relative success as mar
ket-egg producer. 1t is a matter OF COM
mon observation that when the physioli-
gieal machine which we call a hen is
working at its topmost rate of speed
only one egg per day is produced or
course, hen Will occasionally Law two
| eggs in one day, but this is a rare occur1
renee, and only means that the timing Or
the machine was not perfectly regulated
The important and really distressing
thing is that, generally speaking. hens
do not continue for any considerable Pc
Rod to lay even one egg apiece per day
Why is this? What determines. bIolo-
gieally speaking, how many eggs a hen
shall lay? Is the output anatomfcallv
restricted, or physiologically? Or put IL
another way; Does the hen that LAYS
l25 eggs in the year do so because she
has only about 125 eggs in her ovary.
while the 2o0-egg hen has twice as
many? Or, are both these birds equally
endowed in respect to the number of
eggs they carry in their bodies but diff
ferent in their capabilities of fetching
tables and egg-buyers?
These are problems which the writer
has been for some time studying. and
the facts in the case appear to be some
what as follows: all hens. the poorest as
we'll as the best of layers. have an origi-
nal endowment of eggs, very far in ex-
cess of any number which they actually
lay. Roughly speaking, it may fairly
be said that if actual egg production be
measured in hundreds egg endowment
Chat is, the number of oocytes in the
ovary) is measured in thousands Fur
thermore the number of eggs actually
laid bears no relation whatever 10 the
number of oocytes present in the ovary
and potentially capable of being LAID.
In the writer's laboratory a number of
counts have been made of the number OF
oocytes on the ovaries of laying hens
Only those ooocytes which were large
enough to be seen by the unaided eye
could be thus counted,p and it is certain
that in every case there are many more
probably several times as many more
| microscopic oocytes embedded in the
ovarian tissue which are uncounted
But taking only those which are visible
~ thN didiutu eye, lIe results are SUM-
GENTLY striking. few examples may
be cited. Thus a White Leghorn hen
which had laid 1873 eggs in it's puliet
year was killed at the end of that year,
and an ovarian count revealed that
there were then remaining in it's ovary
2i52 ooeytes large enough to be seen by
the naked eye! Each one of these was
potentially capable of becoming a per-
| feet egg. Another White Leghorn hen
| OF the same age as the first laid during
| its pullet year exactly two eggs. Its
| ovary, when subjected to the counting
| process, showed the presence of 2l45
| oocytes visible to the unaided eye. This
| extremely poor layer possessed sub
| stantialy the same anatomical endow-
ment in respect to eggs as the first, yet
| what difference there was In the ac-
| tual layingi No more convincing evil
! dence could be found that the number of
| eggs present in the ovary is no criterion
as 10 the number which will actually be
| laid by bird. Even the humble
guinea-fowl a bird not noted for egg