Egg production performance and quality in laying hens fed a diet rich in bakery by-product

The poultry sector faces increasing sustainability challenges related to feed-food competition, volatility in the cereal markets and the environmental impact of poultry production. In this context, the use of products from the bakery and pasta industry (PBPI) represents a promising strategy within a circular economy framework. The present study aimed to assess the effects of the dietary inclusion of commercial PBPI on productive performance and egg quality in laying hens. The commercial product was composed of bakery by-products, pasta, chocolate residues, and industrial confectionery by-products. From 21 to 35 weeks of age, a total of 180 Lohmann Brown® laying hens received one of three dietary treatments: a control diet (CD), or a diet in which 20 or 40% of the CD was replaced with PBPI (PBPI20 and PBPI40, respectively). All three diets were isoenergetic and isonitrogenous. The study was designed to assess feed intake, body weight, egg production parameters and physical traits, and the chemical composition and fatty acid profile of eggs. The dietary inclusion of PBPI did not affect egg number or oviposition rate. However, egg mass production was significantly reduced in hens fed PBPI40 compared with CD and FFs20. ADFI increased in both groups fed PBPI, resulting in higher FCRs, although overall production efficiency remained satisfactory. Egg quality was largely unaffected by PBPI20, whereas PBPI40 reduced eggshell weight and shell and yolk color intensity. From a chemical perspective, the eggs from hens fed PBPI showed a reduced proportion of saturated fatty acids and an increased content of C18:3n-3, although the overall n-6/n-3 ratio was not significantly modified. In conclusion, the inclusion of PBPI in laying hen diets provides a viable and sustainable feeding strategy. A 20% inclusion rate had no impact on either productive performance or egg quality and resulted in a partial improvement in the nutritional profile of eggs. The present results support the valorization of PBPI as feed ingredients and demonstrate their capacity to enhance the sustainability of poultry production systems.