Researchers in the United States have found that feeding high-oleic peanuts to laying hens enhances egg yolks and oleic fatty acid content in shell eggs.
Previous studies have identified normal-oleic peanuts as a suitable and economical broiler feed ingredient but no research has examined the use of high-oleic peanut cultivars as a feed ingredient for laying hens.
The project, carried out by the US Department of Agriculture Research Service, North Carolina, aimed to examine the use of HO peanuts as a feed ingredient for layer hens to determine the effect on performance, egg lipid chemistry and quality of the eggs produced.
Forty eight 40-week old layer hens were fed a conventional soybean meal and corn control diet or a HO peanut and corn diet for ten weeks in conventional battery cages. Body and feed weights were collected weekly. Pooled egg samples were analysed for quality, lipid analysis and peanut protein allergenicity.
The results showed no significant differences in hen performance or egg quality as measured by USDA grade quality, egg albumen height or egg Haugh unit between the treatment groups.
Greater egg yolk colour scores
However, eggs produced from layer hens fed the HO peanut and corn diet had reduced egg weights relative to the controls. Eggs produced from layer hens fed the HO peanut diet had greater egg yolk colour scores, HO fatty acid and beta carotene levels in comparison to the controls.
The study found that eggs produced from hens fed the control diet had greater palmitic and stearic saturated fatty acids and trans fat content compared to eggs produced from hens fed the HO peanut diet.
All egg protein extracts from all treatments at each time point were non-reactive with rabbit anti-peanut agglutinin antibodies.
The researchers concluded that HO peanuts – an abundant commodity in south eastern United States – could be used to support local agricultural markets of peanuts and poultry and be of an economic advantage to producers while providing a potential health benefit to the consumer through enhanced egg nutrition.