Effect of dietary supplementation with butyric acid or sodium butyrate on egg production and physiological parameters in laying hens

The present experiment was carried out to determine the effect of dietary supplementation with butyric acid and sodium butyrate on selected egg production parameters, egg quality and intestinal morphology and function in laying hens. A total of 432 Lohmann Brown laying hens at 48 weeks of age were randomly assigned to three dietary treatments (9 replicates of 16 birds each). The hens were housed in three-tier battery cages for 24 weeks. All birds were fed on iso-nitrogenous and iso-caloric diets in mash form, and had free access to water. Control group (T1) hens were fed on a basal diet, group T2 received the basal diet supplemented with an encapsulated source of butyric acid (at 500 g/t feed) and group T3 received the basal diet supplemented with protected sodium butyrate (at 700 g/t feed). The number and weight of eggs laid, feed intake, feed conversion, egg quality, bone mineralisation parameters, histomorphological parameters of the small intestine and gastrointestinal tract parameters of hens were determined throughout the experiment. Dietary supplementation with butyric acid and sodium butyrate contributed to a significant increase in eggshell thickness, eggshell weight as a percentage of total egg weight, higher activity of bacterial enzymes in the caecum and higher concentrations of butyric acid in the caecal contents. Hens supplemented with butyric acid protected with the MicroPEARL technology were characterised by higher calcium concentrations in bones and lower ammonia concentrations in the caecum. It can be concluded that both butyric acid sources had a beneficial influence on eggshell quality, tibia parameters and selected gastrointestinal tract parameters. The type of protection (MicroPEARL encapsulation technology) influenced the dose of the product required to achieve the same effect.