The Effect of Varying Steam Conditioning on Enzyme Products in a Pelleted Broiler Diet

Jenna N. Friend* and Joseph Moritz, Davis College of Agriculture, Natural Resources and Design, Division of Animal and Nutritional Science, West Virginia University, Morgantown, WV 26506

Field (Broad Category): Agriculture (Agricultural & Environmental Sciences) 

Student’s Major: Animal and Nutritional Science 

Commercial poultry diets are typically pelleted, involving exposure to saturated steam in a conditioner and frictional force within the pellet die during extrusion. For feed enzymes to have efficacy within the gastrointestinal tract of the bird, the enzymes must be thermally tolerant of the pelleting process. The objective of this study was to determine the activity of eight enzyme products in a corn and soybean meal based diet post pelleting. Enzymes were added at the mixer to 454 kg of basal diet. Each experimental diet was conditioned at 82 °C and then 88 °C for 15 seconds and subsequently pelleted through a 4.7 x 38 mm pellet die. Descriptive pelleting conditions were recorded and pellet quality assessed. Mash and pelleted samples were analyzed for enzyme recovery by two different commercial analytical laboratories. Pellet mill motor load and pellet quality decreased and increased respectively due to increasing conditioning temperature. Most enzymes demonstrated similar trends in activity regardless of laboratory. Enzymes 1, 2, and 3 did not vary in activity due to conditioning temperature while enzymes 4 and 8 decreased in activity due to 88 °C conditioning. Activity of enzymes 5, 6, and 7 were dependent on analytical laboratory. Analytical activity of enzymes post pelleting may predict enzyme efficacy in vivo; however, laboratory bias may influence results. 

Funding: 

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course