Let There Be Light

As the days get shorter, our hens lay fewer eggs. They lay best in the summer when the days are the longest. 

The avian reproductive cycle, which is how a hen produces eggs, is stimulated in poultry by increasing day light.  Egg production increases as day light increases.

This is because light stimulates a part of the hen's brain called the hypothalamus causing it to produce "releasing factors". These releasing factors stimulate the anterior pituitary to secrete hormones known as genadotrophins. Follicle Stimulating Hormone (FSH) and Leutenizing Hormone (LH) are two genadotrophins produced by the anterior pituitary which affect the ovaries. FSH, and to a lessor degree LH, are responsible for normal ovarian follicular growth. As the follicles increase in size, they produce increasing amounts of estrogen and progesterone. Progesterone acts on LH - which then triggers ovulation. Once ovulation occurs, progesterone secretion decreases rapidly (Pesek 1999).  Ovulation is egg production.

 Hens reach their maximum egg laying potential when the day light reaches approximately 16 hours per day (Zadina & Scheideler 2004).

A lack of light can cause a hen's reproductive cycle to shut down, triggering her to cease egg production until spring when the natural day length will increase to sufficient levels once again.

To encourage our hens to continue to lay into the autumn and winter, I extend their day light by a few hours. I have read that artificial light should be added during the morning hours. Sudden darkness can cause chickens to panic and pile up in a corner resulting in suffocation.  By applying extra light in the morning rather than the evening, chickens will naturally go to roost with the setting of the sun.

The boys were excited to help me set up the light this year.

We hooked everything up and ta da!  There was light!

Now, we will see if egg production increases back to summer time levels. We got seven eggs yesterday and only five today.   I'll keep you posted.

References

Pesek, L. (1999). Avian Reproduction: Triggers and Hormonal Changes. Winged Wisdom. http://www.birdsnways.com/wisdom/ww34eiv.htm

Zadina, C. &  Scheideler, S. (2004). Proper Light Management for Your Home Laying Flock.  Institute of Agriculture and Natural Resources. University of Nebraska–Lincoln. https://www.hort.purdue.edu/tristate_organic/poultry_2007/Light%20Management.pdf