The Effects of Moisture Content, Temperature, and Compaction Pressure on the Compressibility of Animal Feed Pellets Produced From Green Pistachio Shell Residues

Abstract

Pelleting is a promising, cost-effective method to optimize the use of garden wastes as animal feed production. Shortage of animal feed and increasing costs are the main reasons to produce feed from garden wastes like green pistachio shell residues. In this study, green pistachio shell residues were gathered and stored in the open air to reduce moisture content, then the dried residues were hammered and sieved to make pellets using a hydraulic pellet maker machine. A factorial experiment with three factors was performed at temperatures of 50 and 65℃, moisture content levels of 15 and 20%, and compaction pressure with a single hydraulic pellet machine at 6000, 8000, and 11000 kPa using a 10 mm mold to investigate the possibility of pelleting green pistachio shell residues. Toughness and fracture energy are the important parameters for optimal pellet-making conditions. The produced pellets were investigated in terms of density, fracture energy, and toughness. The results showed that the effect of compaction pressure on the attributes was significant at the 1% level. The highest values of these attributes were obtained at the highest pressure of 11000 kPa. It was observed that the interaction effect of moisture and temperature on pellet density was the most significant level (1308.13 kg m-3) at temperatures of 65 ℃ and 15% moisture content. Also, the highest fracture energy and toughness (0.0228 J and 1.44×10-14 J m-3) were observed at temperatures of 50°C and 20% moisture content. Therefore, pellets made of green pistachio shell residues have sufficient density, fracture energy, and toughness, which makes pelleting a viable option for reducing transportation volume and costs in animal feed production

Keywords

• animal feed
• pellet quality
• pistachio waste
• transformational industries