Effect of different processing techniques on protein quality of hatchery waste meals.

The nutrient composition and protein quality of hatchery waste (HW) was evaluated by using different processing techniques i.e., cooking, autoclaving and extrusion. The protein contents of the cooked, autoclaved and extruded hatchery waste meals were 43.67, 44.10 and 41.64%, respectively. Microbial analysis of the raw HW exhibited high microbial counts. Different processing techniques reduced the microbial count of HW. Autoclaving reduced both the total viable count (TVC) and total coliform count (TCC) to the minimum compared to other heat treatments. Protein quality of cooked, autoclaved and extruded HWM was measured in terms of protein efficiency ratio (PER) and net protein utilization (NPU). The weight gain in group of broilers consuming reference diet (casein) as sole source of protein was significantly (P <= 0.05) higher compared to the other experimental groups. The PER results from all processing techniques along with NPU data supported an overall conclusion that processing HW with cooking and autoclaving is comparable in terms of NPU. Autoclaving proved more beneficial in terms of PER. But overall values of PER and NPU revealed that processing of HWM can generate nutrient rich, palatable product that was comparable to the traditional feed ingredients.