The paper “Calcium Anacardate Associated with Citric Acid in Diets for Late-Stage Laying Hens“, published in The Journal of Agricultural Science, has been chosen as the latest Editorial Highlight and is freely available to download for one month.

Genetic advances have made it possible for commercial laying hen lines to remainlonger in production. However, after peak production, due to a series of physiological and hormonal changes with age, there will naturally be a decline in performance and egg quality. In addition, the increase in egg size as the bird ages is not accompanied by proportional shell deposition, resulting in eggs with thinner and more fragile shells, which contributes to increased egg losses. However, this natural condition promoted by the aging of laying hens can be accelerated or reduced by the conditions in which the birds are raised, with special attention to environmental and nutritional factors that can increase oxidative stress. The oxidative stress is a result from the increased production of oxidizing compounds to the detriment of antioxidant defense. Consequently, the damage caused throughout the production cycle can contribute to the reduction in the longevity of laying hens in the production system.To mitigate these effects, natural dietary additives have been evaluated over the years and the results are promising in reducing the damage caused by oxidative stress, benefiting bird health and egg quality.

Among the additives evaluated in diets, the use of different phenolic compounds present in various plant extracts stands out. In this sense, there is great interest in the use of anacardic acids, which biological actions have been proven and there is a high availability of raw material for their production. Anacardic acids are phenolic compounds present in different parts of the cashew tree (Anacardium occidentale L.) with a higher proportion in cashew nuts, as it is the main constituent naturally found in cashew nut shell liquid, also known as CNSL.

Process for obtaining calcium anacardate from cashew nut shell liquid and precipitation of anacardic acids with calcium. Source: the authors.

The biological actions of anacardic acids benefiting poultry have been proven with the addition of calcium anacardate to feed. This product is composed of anacardic acid bound to calcium. However, since it is a calcium salt, the release of anacardic acid bound to calcium can be enhanced by acidification of the digestive tract of poultry, enabling its absorption. In this context, the use of citric acid to promote dissociation aims to enhance the action of anacardic acids, since the high acidifying potential of citric acid has been reported as a mechanism of action for the beneficial effects of its addition to poultry feed.

The results indicate that the inclusion of 0.75% calcium anacardate in the diet increases pigmentation and decreases lipid oxidation of the yolk, an interesting effect from the point of view of the stability of fatty acids present in the egg. Regarding the bird, the additive reduces serum lipid oxidation and increases catalase activity in the magnum of laying hens at advanced ages, indicating an improvement in antioxidant defense. These benefits can also be obtained with the combination of 0.50% anacardic acid combined with 0.50% citric acid. We conclude that calcium anacardate has a positive effect on laying hens in the late laying phase and its combination with citric acid can be a strategy to reduce oxidative damage and maintain egg quality.

The Journal of Agricultural Science Editorial Highlights are selected by the Editor-in-Chief and are freely available for one month. View the recent selections here.