Kevin Roberson, PhD
Poultry Nutritionist
Michael Foods, Sioux City, IA
Shell quality is a key parameter important to the success of an egg production enterprise. Many nutritional factors can play a role in preserving shell quality. There is a general belief in the egg industry that there is enough magnesium in limestone to meet the needs of the laying hen. The magnesium requirement has not been investigated for laying hens for about 50 years. Some more recent studies have reported positive results for eggshell quality with supplementation of magnesium to the feed. Research at Michael Foods, Inc. has shown that the addition of 3 lb/ton magnesium oxide to a post-peak layer diet can reduce poor quality eggshells by 30%. Further research is being conducted to determine if shell quality can be improved more by also including extra magnesium in a peaking lay diet.
The use of magnesium oxide to improve bone strength in pullets has been reported recently. Previous work at Michael Foods, Inc. did not demonstrate any improvement in the prevention of keel curvature of laying hens when magnesium oxide was added after 60 weeks of age. Current research is being conducted to determine if supplemental magnesium can prevent bone abnormalities when provided at the onset of egg production.