Every year before the International Poultry Expo, scientists and producers from universities and companies worldwide come together for the International Poultry Scientific Forum. Highlights from this year’s forum include presentations on LED lighting for layers, evaluation of DDGS in layer rations, organic alternatives to synthetic methionine, calcium particle size for pullets, quality of egg yolks with oxycarotenoid supplementation and detection of Salmonella enteritidis in trachea tissue.

Impact of light wavelength

Dr. Brian Fairchild, University of Georgia, presented research on LED and compact fluorescent lighting in chicken houses, which indicates that current spacing may not always be right for an even distribution of light, especially when dimming compact fluorescent lights. A research group from the Universidade Federal da Grande Dourados in Brazil tested five different color LED lights (blue, yellow, green, red and white) for laying hens and compared these to conventional incandescent lamps. They reported that the light color had an impact on egg production, with the best results coming with the red or white LED and the incandescent lamps. Feed intake, egg weight and internal egg quality (specific gravity and Haugh units) were not affected by different light sources.

Low oil DDGS

Several presentations provided much needed data regarding the energy value of low oil DDGS in poultry. Dr. Nick Dale conducted total metabolizable energy tests on the same DDGS sample with varying levels of oil extraction (Table 1). A strong (r=.98) regression equation was formulated (compared to Dale’s 2006 data) that showed a decrease of 38.6 kilocalories per pound for each 1 percent decrease in oil. He recommended an estimate of 2215-2240 kilocalories per pound for low oil DDGS when 5 percent of the fat remains and emphasized that the use of crude fat alone to make adjustments in energy value for DDGS may not be reliable when material is being derived from a variety of sources.

Dr. Michael Persia’s lab group at Iowa State University also conducted chick experiments to formulate a regression equation for estimating apparent metabolizable energy of DDGS samples based on oil content and estimated a 45.6 kilocalorie reduction in apparent metabolizable energy per 1 percent decrease in DDGS oil content. Persia’s group worked with different DDGS samples, versus Dale's group, which extracted more oil from the same DDGS sample. Nonetheless, work from both labs indicated a substantial loss in metabolizable energy from DDGS as oil is taken out, and the estimated loss percentages of oil were very close, only 7 kilocalorie difference.

Iowa State University also tested 15 and 30 percent DDGS in layer diets with or without the antibiotic Tylan, tylosan tartrate supplementation. They reported that high DDGS inclusion rates did not affect production parameters. There appeared to be some effects of Tylan on feed efficiency of young pullets.

Researchers from the Alltech - University of Kentucky Nutrition Research Alliance reported on their work with Program Nutrition strategy and high levels of DDGS (25 or 35 percent) in brown laying hen rations. They reported that higher levels of DDGS inclusions (35 percent) decreased egg production compared to the control corn/soy rations but that when the programmed nutrition premix was added, deleterious effects of high DDGS on reduced feed intake were overcome.

Organic methionine sources

Replacement of synthetic methionine in organic diets is a huge challenge for organic egg farmers. Some innovative research at Penn State University showed how inedible egg white and brazil nut meal could be used to replace synthetic methionine in a cost effective manner without compromising egg production and with some positive effects on feed efficiencies. The inedible egg whites and egg blends are certainly a creative feed source that can help the organic egg industry.


Quality of egg yolks enriched with oxycarotenoids was measured by a research group from Unesp Univ Estadual Paulista, Aracatuba, Brazil. Researchers reported that eggs from hens fed oxycarotenoids had thiobarbituric acid-reactive substances lower than the control group. This is promising information for highly pigmented egg products. 

Limestone particle size and pullets

Our group at the University of Nebraska reported on the effects of limestone particle size on pullet growth and keel bone deformities of white and brown strain pullets reared in aviary systems and conventional cages. Fine blend limestone (0.431 millimeters) and larger particle size limestone (0.879 millimeters) were compared in the two layer strains and housing systems starting at seven weeks of age.

The larger particle size limestone reduced keel bone deformities and improved bone mineral density in cage reared pullets. Brown pullets had higher bone mineral density in both housing systems compared to their white counterparts. Pullets in the aviary system showed a higher incidence of severe keel bone depressions compared to cage reared pullets only when fed the fine blend limestone diets.

This research indicates a need to feed cage pullets a larger particle size limestone after six weeks of age to improve bone mineral density. Our research group also looked at the impact of feeding higher levels of calcium and phosphorous after seven weeks of age on pullet development and found no benefits from increasing dietary calcium and phosphorous by 40 percent from 7-17 weeks of age.

Salmonella enteritidis isolation from tracheas

Researchers in the Hargis lab at the University of Arkansas reported on the detection of Salmonella from tracheas in commercial poultry flocks as an epidemiological tool. Salmonella enteritidis was recovered from 80 percent of the cecal tonsils, 50 percent of the trachea and 40 percent of the liver/spleen from Salmonella enteritidis challenged seven day-old chicks. The authors believe that trachea are a viable detection organ and further hypothesized that airborne movement of Salmonella in poultry houses is a relevant control point to limit spread of infection between flocks.