A system for providing protein for pigs in intermediately sized grower/finisher barns

Feddes, J.J.R., Ouellette, C.A. and Leonard, J.J. 2000. A system for provid ing protein for pigs in intermediately sized grower/finisher barns. Can. Ag ric. Eng 42:209-213. Blend feeding attempts to eliminate excesses and defic iencies in dietary protein associated with conventional phase feeding of gr owing pigs (20 to 110 kg) by meeting their protein requirements on a daily or weekly basis. An increase in carcass lean percentage and a reduction in feed intake and excreted nitrogen are the primary benefits of blend feeding . Blend feeding systems are becoming more common in new facilities, but a s imple inexpensive system that is easy to retrofit to existing, intermediate sized grower barns (similar to 800 growing pigs) is still not available. A prototype blend feeding system has been constructed using mechanical weigh drops (proportioning) and staggered dumping into a single flexible coil de livery anger (mixing) in tandem with feed proximity sensors and computer co ntrolled valves (distribution). When an empty feeder is detected, via a fee d proximity sensor, a batch of feed mixture is prepared and directed to the correct feeder by computer controlled valves. The required protein concent ration in the feed is achieved through one-kg weigh drops of 12 and 20% pro tein feeds in the proper ratio, i.e. 18% protein = 1:3 ratio. Alternate dum ps of the two feeds ensures that adequate mixing occurs in the delivery aug er. Five trials were conducted at three different feed ratios: 1:1, 3:1, an d 1:9. The 15 blended batches were analyzed for batch size and protein cont ent accuracy and protein content coefficient of variation (CV). The nominal batch size was 40.4 kg and the mean batch size error was 1.47 kg (+/-0.47) or 3.64%. The average batch protein content error was 0.63%. Comparing the economics of this system with a commercially available one for a 800-feede r barn (2000 pigs/year), the cost/pig place is $41.75 and $65.25, respectiv ely, if cost recovery is assumed over one year. If the producer installs th e components of the system, the cost/pig place is $28.00.