Use of Artificial Lighting to Increase Photoperiod Length for Pasture-Raised Laying Hens to Improve Egg Productivity and Quality

Document Type


Degree Name

Master of Science (MS)


Ag Science and Natural Resources

Date of Award

Spring 2015


This project investigated the effects of commercial-style photoperiod in a sustainable-style management practice on laying hen deposition rate. Twenty-seven hens were raised in identical conditions. Three breeds were represented by nine hens each. Within each breed, three hens were randomly assigned to one of three groups, resulting in three groups of nine hens. Each group was randomly assigned to a coop, and each coop was assigned a management system treatment. Treatments included: commercial (COM), pasture-raised (PAST) and pasture-raised with an extended, commercial-style photoperiod (PEP). The COM hens were raised indoors with ad libitum feed and a photoperiod of twelve to fourteen hours. This photoperiod became progressively longer as the study progressed. Housing for the PAST hens was identical to that of the COM hens; however, PAST hens had no extended photoperiod and were provided additional access to ten square meters of pasture per hen. Housing for the PEP hens was identical to that of the PAST hens with an additional photoperiod of twelve to fourteen hours. Hen deposition rate was measured once per week over a 56-day period. It was hypothesized that the deposition rate of the PEP hens would be higher than the PAST hens. The study was successful in showing that an increased photoperiod will increase production in both commercial and pasture-style production systems. Due to the observed increase in egg quality measurements that pasture-raised eggs exhibit over commercial-style eggs such as yolk color , albumin height, and egg weight (P < 0.05), the date supports the idea that pasture-raising eggs provides benefits to producers and consumers. Implications from this study will improve sustainability because it has quantified the benefits of additional light and pasture on egg production and egg quality in pasture-raised hen production systems. This knowledge should help poultry producers attain greater productivity in their sustainable management programs.


Jackie L. Wahrmund

Subject Categories

Agriculture | Animal Sciences | Life Sciences