Optimizing dietary energy and amino acid densities in male broiler chickens: Impacts on performance, cost efficiency, and carcass quality

Abstract

Dietary metabolizable energy (ME) and amino acid (AA) densities not only drive key performance metrics but also constitute over 90% of total feed costs. Optimizing ME and AA levels is thus a strategic approach to enhancing cost-effectiveness. This study investigated how manipulating ME and AA levels at different growth phases affects Ross 308 male broiler chicks' performance and carcass yield. The standard diet (T1) followed Aviagen 2022 recommendations, while six treatments with varying ME and AA levels were administered: T2: reduced ME by 100 Kcal/kg in starter and 75 Kcal/kg in grower; T3: similar to T2 but with a 50 Kcal/kg ME increase in withdrawal; T4: reduced ME by 100 Kcal/kg and +4% AA increase in starter, with reduced ME by 75 Kcal/kg in grower; T5: similar to T4 but with a 50 Kcal/kg ME increase in withdrawal; T6: reduced ME by 100 Kcal/kg and +4% AA increase in starter, reduced ME by 75 Kcal/kg and +3% AA increase in grower, and reduced ME by 50 Kcal/kg in finisher; T7: similar to T6 with a 50 Kcal/kg ME increase in withdrawal. Final BW, FI, and FCR were not significantly affected by ME and AA densities. Diets with reduced ME in the starter and grower phases resulted in the lowest feed cost per kg of BW. Carcass traits did not differ across treatments. In conclusion, reducing dietary ME by 100 and 75 Kcal/kg in starter and grower phases, respectively, can potentially lower feed costs without adversely affecting productivity and carcass traits.