Different particle sizes of laying hens diets and it's effect on blood biochemical parameters, ileal digesta viscosity and nitrogen retention

The aim ofthis work was toevaluate the effect ofdifferent particle sizes ofhens diets onblood biochemical parameters, ileal digesta viscosity and nitrogen retention. Inthe experimental part, the effects ofdifferent physical structure were investigated ontwo groups oflaying hens ofthe Bovans Brown hybrid from 76 to80weeks ofage. Afinely ground mash diet [geometric mean diameter (GMD), 632µm] and acoarsely ground mash diet (GMD, 1258µm) with the equal nutritional content were used. Inthe experiment, the particle sizes ofthe feed mixtures were analysed and compared with the particle size ofunaccepted feed residues using afeed separator. Furthermore, feed consumption, live weight oflaying hens, blood biochemical parameters, digestive viscosity and nitrogen retention coefficient were assessed. The study revealed that the particle sizes ofhens’ diets significantly influenced the nitrogen retention coefficient, with higher values observed inthe finely ground diet ascompared tothe coarsely ground diet (30.3 vs 24.0%; P<0.05). However, nosignificant differences were observed infeed intake, live weight, blood biochemical parameters, ordigesta viscosity between the dietary groups (P>0.05). This finding highlights the potential of diet structure optimisation to improve nutrient utilisation efficiency, which is particularly relevant for reducing nitrogen excretion and its environmental impact. These novel insights provide a foundation for further research on the effects of feed structure on productivity and organ health.