| Popis: |
Modern swine facilities have not been designed for maximization of manure value or minimization of ammonia emission. These benefits can possibly be achieved by harvesting urine and feces separately on a conveyor belt placed at a 4° angle beneath the slats. Urine drains off this belt into a gutter leading to a closed storage vessel while feces remain on the belt. Such a belt was evaluated in a partially slatted swine facility housing 80 grower pigs. Through the use of play-chains in the corners, solid pen partitions around the solid floor, and open partitions around the slatted floor, defecation behavior was directed to the slats. In trial 1, the optimal time of day for fecal collection, and belt performance under steady state use were determined. In trial 2, belt performance under steady state operation was tested, and animal performance was compared with that from a conventional facility. The belt system was timer-operated requiring no labor other than cleaning the scraper. Collections at 6 am resulted in a 10% increase in dry matter over 6 pm. During steady-state collections at 6 am, dry matter (DM) was 52±10% and 54±9% in trials 1 and 2, respectively, and 17% of feed DM was recovered as fecal DM (0.24 kg fecal DM/pig/day). Urine collections in trial 2 averaged 1.5±0.4 l/day or 42% of the water intake. Ammonia emissions were derived solely from the pen surface (unaffected by the fecal load on the belt), and thus were dependent on the defecation pattern of the animals. When defecation occurred predominantly on the slatted portion of the pen, ammonia emission was 1.0±0.2 kg per pig place per year. Pigs housed in the belt facility (trial 2) had a 6% improved feed efficiency compared to those in conventional housing. In conclusion, the belt housing system was easy to operate, resulted in good animal performance, and most importantly, yielded feces of 53% dry matter, a clean urine stream, and only 1 kg ammonia emissions per pig place per year. |
