Can Midnight Feeding Improve Shell Quality in Layers?

Broken and cracked eggs represent a major economic loss on commercial farms. Approximately 6.5% of all eggs produced are unusable because of shell quality problems. Because most eggs are laid in the morning, and because it takes about 20 hours for the hen to form an egg shell, the hen has a large demand for calcium through the night during the period of shell formation. Previous research has shown that the digestive system of the hen has less total calcium during the early morning than in the late afternoon. Little calcium is available to the hen after midnight when most of the eggshell is being formed. This begged the question; "if we ran the lights and the feeders for 45 minutes at midnight, would the hens consume the feed made available to them and would they produce better quality shells?"

Procedures

Three separate field experiments using DeKalb and Hy-Line strains were set up. In each experiment, the effect of running the lights and feeders for 45 minutes at midnight in one house was compared to a control house. A sample of eggs was collected at 900 h and at 1500 h. The specific gravity and shell weight per unit of surface area were calculated as indicators of shell quality. The hens were given midnight feeding for 4 days in a row and eggs were collected daily for the same 4 days over a number of flock ages.

Results and conclusions

Shell quality was improved by turning on the lights and feeders for 45 minutes at midnight. This was especially effective for eggs collected at 900 h. This would seem logical as the hens who were fed at midnight had a supply of calcium during the time of heavy demand. Hens who lay their eggs later in the day (1500 h collection) have access to calcium for a greater percent of the time during shell formation.

Summary

Midnight feeding of commercial laying hens can improve eggshell quality. However, it is necessary to turn on the lights and run the automatic feeder in order to stimulate the laying hens to consume feed. Hens need to be trained to consume feed when the lights and feeders are running. Midnight feeding may be more beneficial for improving the egg shell quality of eggs laid in the morning than for eggs laid in the afternoon. In this study, adverse effects of midnight feeding on egg production were not recorded.

Summarized from: R. D. Harms, C. R. Douglas, and D. R. Sloan, 1996. Midnight feeding of commercial laying hens can improve eggshell quality. Journal of Applied Poultry Research 5:1-5.

Source: Poultry Research Centre News - Vol. 5 No. 2
Published on the Goverment of Alberta, Agriculture and Rural Development website