The assessment of black soldier fly (Hermetia illucens) pre-pupae, grown on human faecal waste, as a protein source in broiler and layer diets

[摘要] ENGLISH ABSTRACT: The aim of this study was to investigate the effect of processing of black soldier fly (Hermetia illucens) pre-pupae meal (BSF), grown on human waste, as a protein source in broiler and layer hen diets (10% inclusion level). For the broilers, the diets were iso-nitrogenous and iso-energetic, containing 10% pre-pupae meal. The potential of these (BSF) as a protein source in broiler diets were evaluated, along with the production parameters, carcass quality (physical and chemical), possible toxicities, feed safety and digestibility of the pre-pupae were investigated in broilers. Eight different processing treatment methods were used on the BSF in the broiler trials. The methods included: washed in water at 62°C for 30min (Trt1), 62°C for 60min (Trt2), 72°C for 5min (Trt3), 72°C for 15min (Trt4), 100°C for 2min (Trt5), 100°C for 5min (Trt6), rinsing in 5% propionic acid (Trt7) and rinsed in 5% formic acid (Trt8).The production trial indicated no treatment differences for cumulative feed intake and average daily gain (ADG). Treatment differences were observed between the BSF diets and the control, with the BSF diets achieving better results regarding feed conversion ratio (FCR), protein efficiency ratio (PER), european protein efficiency factor (EPEF) and final live weight. The organ weights and the gut toxicity were measured. The analysis indicated no treatment differences with regards to the gut pH, organ weights and neither with the histomorphology of the duodenum and jejenum. No significant treatment differences were observed regarding the slaughter weight, breast muscle yield and the proximate analysis. However, significant differences were observed in the dressing percentage, with the control diet achieving higher dressing percentages than most of the BSF diets. The breast muscle of broilers receiving BSF diets produced meat that was redder than that of the control diet. Significant differences were observed between Trt2 and Trt8 with regards to pH of the meat (pH of 6.4 and 6.0 respectively). For the total tract digestibility study the following were evaluated: protein, fat, fiber, ash, amino acids and apparent metabolisable energy (AME). There were significant differences among all the treatments with regards to AME and the other nutrients. Trt1, Trt2, Trt3 and Trt5 had the highest coefficient of total tract digestibility (CTTD) over all the nutrients analysed. These treatments had CTTD's over 0.9 for crude protein and the essential amino acids.The layer trial only investigated four out of the initial eight treatment methods of the pre-pupae (Trt1, Trt3, Trt5 and Trt8), with two housing methods for each treatment (naturally ventilated and free range). The eggs were stored at room temperature at different time intervals before analysis: 1) the same day, 2) one day after collection, 3) one week later, 4) two weeks later and 5) one month later. The data collected were egg weight, shell weight, yolk weight, yolk colour and albumen height. The albumen height was used to determine the Haugh unit (HU). It was concluded that there were no significant differences between the dietary treatments with regards to shell weight, HU, shell thickness and colour. There were, however, observed differences between dietary treatments for egg weights and yolk weight. Trt3 house (naturally venitlated) differed significantly from the other treatments with regards to egg weight. While Trt3 house (naturally venitlated) and Trt5 house (naturally venitlated) differed significantly from the control group regarding yolk weight. It was observed that with increased storage time the quality of the eggs degraded (egg weight, yolk weight and HU). There were significant differences between treatments with regards to egg weight and yolk weight in storage group 1. There were also significant differences in storage group 2 as pertaining to egg weight, Trt3 house being significantly heavier than the other treatments except for Trt1 house. Trt1-3 free range also differed significantly from the other treatment groups.It can be concluded that BSF grown on human waste can successfully be used as a protein source in broiler and layer diets. Good production values along with carcasses of acceptable physical and chemical quality can be produced in broilers, with no measurable toxic effects. The BSF are also highly digestible irrespective of treatment. It was also concluded that eggs produced from diets containing BSF grown on human waste were still of good quality with no adverse effects to be found.

[发布机构] Stellenbosch University