Influence of supplemental chromium picolinate on nitrogen balance, dry matter digestibility and carcass traits in growing-finishing pigs

Abstract

Four trials were conducted to determine the influence of feeding 200 ppb Cr as chromium picolinate (CrPic) on dry matter digestibility, nitrogen balance and leanness in growing-finishing pigs. In three similar trials, 12 crossbred barrows (littermate pairs) were used in each trial for two nitrogen balance periods (end of grower and end of finisher). After the second nitrogen balance period, all the barrows were killed and carcass data were collected. Growth rate was similar for control and CrPicfed pigs in all trials. Absorption of N was increased by feeding CrPic (P < .07). Neither retained N nor apparent biological value (aBV) was affected by added CrPic. Dry matter digestibility was increased (P < .03) by feeding CrPic. Dressing percent and backfat thickness at the tenth and last rib were not different between pigs fed diets with or without CrPic. Longissimus muscle area was larger (P < .04) for pigs fed CrPic. For blood samples taken 30 min, 4 h, and 12 h after feeding, serum glucose, urea N, and cholesterol concentrations were similar for pigs fed diets with or without added CrPic. In Trial 4, 12 crossbred barrows (littermate pairs, initial BW=82.0 kg) were used in a switch-back design with an extra period. Dry matter digestibility (P < .02) and N absorption (P < .06) were improved. No carryover effect was observed. These results showed that pigs fed 200 ppb Cr from CrPic had larger longissimus muscle areas without their backfat thickness being affected and they appeared to have greater nitrogen absorption, although retained N and apparent biological value were not significantly greater than control pigs.