Poultry Judging Practice Test

To stimulate egg production, increasing day length beyond what duration offers no economic benefit?

1. 12 hours

2. 15 hours

3. 17 hours

4. 20 hours

The correct answer is: 17 hours

Increasing day length is a common strategy used in poultry management to stimulate egg production, particularly in layers. In general, hens require a certain amount of light exposure each day to maintain optimal reproductive functionality. When considering the impact of day length on egg production, 12 hours of light is the minimum required for production to commence. However, as the duration of light increases, the stimulation of egg production continues to rise up to a point. At 15 hours of daylight, hens can maintain productive levels, and extending beyond this duration into 17 hours does also support enhanced production rates. Yet, the science of poultry production indicates that there is a diminishing return on the benefits of increasing light duration. Beyond 17 hours, especially when reaching 20 hours, the additional stimulation does not lead to a proportional increase in egg output and can even lead to negative effects, such as stress in the hens or disruptions in their natural circadian rhythms. Therefore, the most economically and biologically sensible threshold is at 17 hours. Beyond this duration, increasing the light further does not provide beneficial returns in terms of egg production, making it an inefficient practice to implement for production purposes.