Abstract
The objective of this experiment was to determine the effect of different inclusion levels of corn starch and fine ground corn with different conditioning temperature or die thickness on pellet quality. Experiment 1, treatments were arranged in 3×2 factorial design of corn starch inclusion level (0, 5 and 10%) and die thickness (4mm×13mm and 4mm×22 mm). Experiment 2, treatments were arranged in 3×2 factorial design of fine ground corn inclusion level (0, 10 and 20) and conditioning temperature (80 and 85°C) with treatments pelleted using a 4mm×22mm die (5.6 L:D). In both experiments, treatments were pelleted using a model CL-5 CPM pellet mill (Crawfordsville, IN). The result of experiment 1 demonstrated that there was no interaction between corn starch inclusion level and die thickness on modified pellet durability index (PDI), (P=0.636). Increasing die thickness from 12.7 to 22.2 mm increased PDI from 43 to 70% (P< 0.001). There was a linear decrease (P< 0.001) in PDI as the corn starch inclusion level increased from 0 to 10% (64, 60, and 46%, respectively). The result of experiment 2 demonstrated that there was no interaction between fine ground corn inclusion level and conditioning temperature on PDI (P=0.541). The fine ground corn inclusion level did not impact PDI (P=0.298). Increasing conditioning temperature from 80 to 85°C increased PDI (P< 0.001) from 76 to 85%, respectively (P< 0.001). Based on the results, the use of pure corn starch was not an effective binding agent in the feed when the diet contains at least 60% ground corn. The ratio of small corn particles to large corn particles in the diet did not impact pellet quality when the diets were conditioned above 80°C for 35 sec and then pelleted with a 5.6 L:D die. Increasing die thickness and conditioning temperature improved pellet quality.
Resolving poor pellet quality and maintaining amino acid digestibility in commercial turkey diet feed manufacture
