(Young Scholars) Effects of feed truck unloading and swine barn feed line location on pellet quality and nutrient segregation

Abstract Text: Two experiments were conducted at a commercial feed mill and 6 commercial wean to finish pig sites to determine the effects of feed truck unloading auger RPM on pellet quality and unloading time, and the effects of feed line location on pellet quality and nutrient concentration of intact pellets and their fines. In Exp. 1, pelleted feed was unloaded using 3 speeds (900, 1,150, and 1,400 RPM) from each of 8 compartments of a feed truck (Walinga Inc., Guelph, Ontario). Six samples per compartment were collected creating 16 replications/unloading speed. There was an unloading speed × trailer compartment interaction (P=0.031; SEM=17.4). The difference in unloading time from the front to rear compartment was greatest at the slowest unloading speed and similar at the two highest unloading speeds (70 vs. 35 and 37 s). The percentage of fines formed during unloading was not influenced by unloading speed, but tended to increase (quadratic; P=0.081; SEM=2.27) from the front (8.2%) to the rear compartment (10.7%). In Exp. 2, pelleted feed samples were collected during unloading into a commercial feed bin at 6 finishing pig sites with 2 feed lines, resulting in 12 replications per feed line location. Samples were collected from the feed line at 6, 35, and 76 m from the feed bin. There were no interactions between feed line location and nutrient profile of the fines and pellets. There was no effect of feed line location on pellet durability index, percentage fines, percentage fines formed, or the nutrient profile of pellets or fines. Across locations, fines had decreased (P<0.05) CP (12.4 vs 15.3%; SEM=0.14) and P (0.37 vs 0.40%; SEM=0.006), but greater (P<0.05) ADF (3.7 vs 3.2%; SEM=0.24), crude fiber (2.7 vs 2.2%; SEM=0.09), Ca (0.47 vs 0.44%; SEM=0.012), ether extract (6.2 vs 5.2%; SEM=0.11), and starch (47.4 vs 44.7%; SEM=0.42) for the fines and pellets, respectively. In conclusion, the front compartments closer to the truck cab resulted in fewer fines formed from loading to unloading. Decreasing unloading speed significantly increased the amount of time taken to unload a feed truck but did not alter fines formed. Feeder distance from the bin did not influence fines formation. There were significant differences in nutrient profile between fines and pellets. Understanding the location of fines creation during the feed delivery process may allow for alternative methods to reduce the formation of fines and subsequent nutrient segregation.

Keywords: feed mill, fines, pellets