Enhancing Growth Performance, Organ Development, Meat Quality, and Bone Mineralisation of Broiler Chickens through Multi-Enzyme Super-Dosing in Reduced Energy Diets

SIMPLE SUMMARY: The global population is expected to rise from 7.2 billion as of 2019 to 9.7 billion in 2050, putting pressure on farmers to increase production capacity to ensure food security whilst simultaneously improving food sustainability. Poultry is an important meat, as chickens have high feed efficiencies and short production cycles, making it an affordable, nutritious source of protein. Strategies to improve the production performance of broilers will require significant research; one nutritional strategy is improving the efficiency of feed utilization via the addition of exogenous enzymes into diets. This study aimed to identify the optimal multienzyme, Natuzyme, dose rate at three energy levels based on production performance, organ development, meat quality, and bone mineralization in broiler chickens. Results revealed that all dose rates of Natuzyme were able to mitigate the negative effect of energy reductions. Organ development and meat quality remained consistent across treatment groups, except for the gizzard and meat moisture content, which were affected by super-dosing Natuzyme. Bone mineralization was restored with the inclusion of Natuzyme. In conclusion, super-dosing Natuzyme in reduced energy diets at a dose rate of 700 g/t can improve performance parameters and thus profitability for producers and can improve the sustainability of production. ABSTRACT: This study identified the optimal multi-enzyme dose rate at three energy levels based on the production performance of broiler chickens. A 42-day grow out trial was conducted using 576 day-old mixed-sex ROSS308 broiler chickens in a 3 × 4 factorial arrangement in a completely randomized design. Diets consisting of three metabolizable energy (ME) levels: standard energy (STD), 150 kcal/kg energy reduction (STD-150), and 200 kcal/kg energy reduction (STD-200), were cross factored with four multi-enzyme inclusion levels (0, 350, 700, and 1000 g/ton). The average daily feed intake and feed conversion ratio increased linearly (p < 0.001) as the dietary ME was reduced, and the multi-enzyme addition improved the feed conversion ratio (p < 0.05) and mitigated the negative effect of the reduced energy diets (RED) on feed intake and feed conversion ratios. Carcass composition, organ weights, and meat quality were not affected by the experimental diets. The RED decreased abdominal fat weight (p < 0.05). Total ash, calcium, and phosphorous contents of the tibia bone were improved (p < 0.04) when the RED were supplemented with the multi-enzyme. Super-dosing multi-enzymes in RED mitigates the negative effect of ME reduction on growth performance while maintaining organ development and meat quality and improving bone mineral content.