135. Xylanase supplementation enhances growth performance post PRRS outbreak and increases carcass yield

Abstract

Xylanase hydrolyzes arabinoxylans into smaller chain xylo-oligosaccharides, which are fermented by bacteria in the hind gut. Consequently, a shift towards fiber utilizing bacteria occurs, and these bacteria also produce SCFAs, like butyrate. These changes may help with gut functionality and fiber utilization, thus increasing growth performance. Therefore, an experiment was conducted using 504 pigs (initial BW of 6.49 kg) to determine growth performance and carcass data of pigs fed a xylanase supplemented diet. Each dietary treatment was fed to 12 replicate pens with equal weight containing 21 barrows or gilts. Two dietary treatments were formulated and fed over 7 phases. A control (CON) diet was formulated to contain no supplemental NSPases. An additional diet (EXT) was formulated like the CON except that it contained 16,000 BXU/kg of diet of xylanase (Econase XT, AB Vista). Pens of pigs were weighed at 21 day intervals, and feed disappearance was measured so that ADFI, ADG, and G:F could be calculated. Pigs were marketed in 3 cuts and carcass data was collected. Data were analyzed using a t-test. The experimental unit was the pen for all parameters. Near weaning, the barn experienced a natural occurrence of PRRS. There was no difference in ADFI, ADG, or G: F for the first 42 days, which included the time around the natural challenge. Post challenge (d42 to the end), EXT stimulated (P < 0.05) intake in EXT (2.29 vs. 2.20 kg). As a result, ADG was greater (P < 0.05) for EXT compared to CON. There was no difference in percent lean, loin depth, or fat depth among dietary treatments. Pig weight (kg) and carcass weight (kg) tended (P = 0.056) to be higher for EXT (125.98; 101.06) over CON (123.11; 98.73). Yield was greater (P < 0.05) for EXT (75.11%) compared to CON (74.63%).