Effect of die channel press way length on physical quality of pelleted cattle feed

Abstract

The purpose of this study was to investigate the ffects of length of die channel press way on physical quality of pelleted cattle feed. Pellet processing of compound feed was carried out at the Institute of Food Technology, Novi Sad, Serbia. For this study the complete mixture for dairy cows was acquired. Mixture was made from corn, wheat meal, sunflower meal, soybean meal, limestone, dicalcium phosphate and premix. Mixture was pelleted on flat die pellet press. Three dies with different die thicknesses were used. Diameter of die openings of all three dies was 6 mm, and die press ways were 18,36 and 48 mm respectively (D/L 1:3, 1:6, and 1:8). Increase of length of die channel press way improved the pellet quality in terms of hardness. Thus, pellets made at 1:8 die had the highest value of hardness. Differences between all three groups were significant (p<0.05). Pellet durability results are not in correlation with press way lenght. This is presumably due to the difference in moisture content because moisture has lubricating effect. Moisture content had higher influence on the pellet durability when comparing with the die press way lenght. When increasing press way from 1:3 to 1:6, specific energy comsumption is increased approximately 40%. On the other hand, when using 1:8 die, specific energy consumption was increased by only 5%. Reason for this is higher moisture content for 1:8 die.