Food waste sources are cheap and can be very nutritionally valuable feed stuffs. THI HIEP DAO, NISHCHAL SHARMA, BOB SWICK, NORM BOYLE and AMY MOSS* demonstrate that food waste sources are a valuable feed ingredient for laying hens, and diets may be based completely on food waste.
An estimated 7.3 million tonnes of food waste is dumped annually in Australia, leading to substantial environmental and economic losses. Additionally, poultry feed represents the majority of production cost. Therefore, an experiment was designed to evaluate food waste as a feed for laying hens.
Trial design
A total of 150 Isa Brown laying hens at 24 weeks of age were allocated to 3 treatments on the basis of body weight to maintain uniformity between the treatments. Treatments consisted of a control wheat-sorghum-soybean meal-based diet, a food waste-based diet, and a 50-50 blend (Table 1).
Table 1: Composition of experimental diets.
Waste streams were heat processed (for biosecurity) and blended into a complete mash feed. The food waste streams were ground so that they have a similar consistency of a commercial layer mash. Diets were formulated to meet Isa Brown minimum nutrient requirements.
The food waste diets were made up from individual waste streams which were thoroughly characterised before feed formulation along with the standard ingredients for the control diet. Feedstuffs were analysed for nutrient content including dry matter, gross energy, crude protein, amino acids, crude fat, crude fiber, and mineral composition using standard procedures (AOAC, 1994) prior to diet formulation. In meeting the minimum nutrient requirements, the food waste-based diet contained higher concentrations (g/kg) of crude protein (17.8 vs 25.6%), fat (13.44 vs 5.28%), fiber (8.91 vs 2.78%), available phosphorus (1.02 vs 0.45%) and sodium (0.45 vs 0.18%) compared to the control diet (Table 2). Fewer synthetic amino acids were needed as the food waste sources were high in protein. They were also very energy dense.
Table 2: Nutrient specifications of experimental diets.