## 2 Materials and Methods
### Experimental Design and Diets  
This study was conducted at the University of New England Laureldale Layer Cage facility in Armidale, New South Wales, Australia. The experimental design, dietary treatments, hen management, data collection, feed formulation, and analysis followed [PERSON] et al. [23]. In brief, [PERSON] laying hens (\(n=150\)) at 23 weeks of age were randomly distributed to three dietary treatments including a standard/control diet, a recycled food waste-based diet, and a 50:50 blend of these two diets. Experimental diets were steadily increased over 10 days during weeks 23-24 as an adaptation period and were then offered to hens from week 24. Each treatment consisted of 50 replicate cages (30 cm width \(\times\) 50 cm depth \(\times\) 45 cm height) with a single hen per cage. The hens' starting weights were similar between the treatments. Specifically, the average weights of hens on the control, food waste, and 50:50 treatments were 1959 g, 1922 g, and 1926 g at 24 weeks of age, respectively. The study included 2 laying phases with 20 weeks each (24-43 and 44-63 weeks of age). Hens were raised in a curtain-sided house with two nipple drinkers and one feeder per hen over 40 weeks from 24 to 63 weeks of age. Hens had _ad libitum_ access to the feed and clean water and were raised under 16 h of light and 8 h of dark throughout the experimental period. Temperature and relative humidity inside the hen house were recorded daily. All diets were provided in mass form and satisfied the minimum nutrient recommendations for Hy-Line Brown laying hens per Hy-Line International [40]. Four feeding periods were applied: 24-37, 38-43, 44-58, and 59-63 weeks of age. Food waste streams were collected from various places, including bakeries, breweries, abattoirs, hospitals, nursing homes, fish processing facilities, pubs and restaurants, and vegetable and fruit markets. After collection, food waste streams were checked for foreign objects, separated into different categories, and processed by Food Recycle Ltd. (Candelo, New South Wales, Australia) using a patented production process to sterilize and dry the material into suitable granular powders for poultry feed (patent number P11980.WO) [41]. Specifically, the process comprises treating the categorized food waste separately to substantially destroy all pathogens by heating at 350 \({}^{\circ}\)C for less than 10 s, grinding the treated food waste, and finally mixing the treated ground food waste streams into the layer feed based on their nutrient contents [41]. Feed ingredients, including food waste streams, were analyzed for dry matter, gross energy (GE), crude fat, crude fiber, crude protein (CP), amino acids, and mineral levels following the AOAC [42] prior to diet formulation. Levels of metabolizable energy and total and digestible amino acids for the major feed ingredients used in the control diet were analyzed by near-infrared reflectance spectroscopy (Foss NIR 6500, Hillered, Denmark). The levels of metabolizable energy and digestible amino acids in the food waste streams were set at 65% of the total measured energy and amino acids, following previous food waste diet research [33; 35; 43]. The analyzed nutritional composition of the feed ingredients and food waste streams was used to formulate the diets via feed formulation software (Concept 5 version 13.11.19, CFC Tech Services, Inc., Browverille, MN, USA). Minor ingredients, including crystalline L-lysine HCl, D,L-methionine, enzymes (xylanase, phytase), antioxidant, pigments, and layer vitamin-mineral premix, were supplementedinto the diets where necessary to satisfy the nutritional requirement of Hy-Line Brown laying hens. Titanium dioxide was supplemented in all diets at 0.5% during the last feeding period (59-63 weeks of age) as an inert marker for ileal protein and energy digestibility determination. The mixed diets were subjected to proximate and NSP analyses using standard methods [42] to confirm the formulation objectives.