Supplemental chromium picolinate influences nitrogen balance, dry matter digestibility, and carcass traits in growing-finishing pigs

Four trials were conducted to determine the influence of feeding 200 ppb Cr as chromium picolinate (CrPic) on DM digestibility, N balance, and carcass traits of growing-finishing pigs. A 15% CP corn-soybean meal diet was fed during the grower phase, and a 13% CP corn-soybean meal diet was fed during the finisher phase. In each of three trials, crossbred barrows (six littermate pairs) were used for two N balance periods (end of grower, 61.3 kg; end of finisher, 98.9 kg). After the second balance period, all the barrows were killed and carcass data were collected. Initial and final BW were 23.5 and 104.9 kg, respectively. Growth rate was similar for control and CrPic-fed pigs in all trials. The rate of N absorption was increased by feeding CrPic (P < .05), but N retention was increased only numerically (P = .14). Dry matter digestibility was also increased by feeding CrPic (P < .02). Dressing percentage and backfat thickness at the 10th and last rib did not differ between treatment groups. Longissimus muscle area was larger (P < .05) for pigs fed CrPic. In Trial 4, crossbred barrows (six littermate pairs; initial BW, 82.0 kg) were used in a switch-back design with an extra period. Digestibility of DM (P < .02) and absorption of N (P < .06) were improved with only a numerical increase (P = .22) in N retention. No carryover effect was observed. These findings show that pigs fed 200 ppb Cr from CrPic can have larger longissimus muscle areas and that Cr supplementation improved N absorption and DM digestibility.