Impact of Repeated Out-Of-Feed Events and Fineness of Grind on Grow-Finish Performance

University of Nebraska 2006 Swine Day Report. Out-of-feed events are a growing problem in nursery and grow-finish facilities due to issues associated with feed delivery to bulk bins and bridging of feed in bulk bins. Reports of bridging are increasing as producerscontinue to reduce the fineness of grind for complete diets in order to improve feed conversion. A study was conducted to examine the effect of repeated out-of-feed events and diet particle size on barrow performance in a wean-to-finish facility beginning six weeks after weaning. Corn-soybean meal based diets were either coarse (1,266 microns) or medium ground (1,019 microns) for the duration of the experiment. Within particle size, pigs were never out-of-feed or denied access to feed for a 20-hour period beginning at noon on a random day each week for 16 weeks. For the first eight weeks, weekly out-of-feed events reduced daily gain 0.15 lb/day compared to the never out-of-feed treatment (P<0.001) due to a reduction in daily feed intake (P=0.003) with no effect on feed conversion efficiency. There was no effect of out-of-feed events on daily gain or feed conversion for the second eight week period of the experiment. For the 109-day trial period, weekly random 20-hour out-of-feed events resulted in a 0.077 lb/day decrease in daily gain with no effect on feed conversion. The 247 micron reduction in average diet particle size resulted in a 0.091 lb/lb improvement in overall feed conversion (P=0.001) for the coarse versus medium ground diets. There was no effect of any experimental treatment on skin lesion scores, a measure of pig welfare and injury from fighting at the feeder. There was no interaction of out-of-feed events and diet particle size. These results suggest that out-of-feed events can have major consequences for pig performance. However, pigs appear to adjust to weekly out-of-feed events, even when they occurred on a random day within each week. The penalty for repeated out-of-feed events is a reduction in daily gain, with no impact on feed conversion, while the penalty for coarser ground diets is a worsening in feed conversion, with no change in daily gain.