Effects of nanoparticle chromium on chromium absorbability, growth performance, blood parameters and carcass traits of pigs

Abstract

The aim of this study was to investigate the effect of dietary supplementation of nanoparticle trivalent chromium on chromium absorbability, growth performance, blood parameters and carcass characteristics of pigs. In Trial 1, five growing pigs (Landrace × Yorkshire × Duroc) (initial average weight was 31.3 ± 2.0 kg) were used in a 5 × 5 Latin square design as the Control group (without supplement of chromium), the chromium chloride group (CrCl3), the chromium picolinate group (CrPic), the nanoparticle chromium chloride group (NanoCrCl3), and the nanoparticle chromium picolinate group (NanoCrPic). The pigs were adapted for 7 days, followed by a 5-day test period and a collection period. The chromium was added at a 200 μg/kg level to the diet using different chromium sources for evaluating the chromium absorbability. The results of Trial 1 indicated that there were no differences in feed components digestibility among the groups, but the absorbability of chromium in the NanoCrPic (27.5%) group was the highest, whereas that in the CrCl3 group was the lowest (4.91%). Moreover, the chromium source, nanoparticle size and interaction effects were observed between these two factors (P < 0.001). In Trial 2, 60 Landrace × Yorkshire × Duroc growing pigs (average bodyweight was 76.7 ± 4.5 kg) were randomly allotted to five dietary treatment groups as used in Trial 1, each group with four pens (three pigs/pen). The study was conducted for 60 days. Their growth performance, carcass and meat traits were also evaluated. Trial 2 results indicated that feed intake in the chromium-added groups was greater (P < 0.007) than that in the Control group. The average daily bodyweight gain in the chromium-added groups was greater than that in the Control group (P = 0.046). The serum non-esterified fatty acids level was lower (P < 0.0001) in the NanoCr groups. Serum chromium concentration was increased by dietary chromium supplementation, and the chromium source, nanoparticle size and their interaction effects (P < 0.001) were observed. The average back fat thickness in the CrPic and NanoCrPic groups was lower (P < 0.05) than that of the Control group. Meat chromium content was elevated by dietary chromium supplementation, particularly in the CrPic and NanoCrPic groups (P < 0.05). The chromium source, nanoparticle size and interaction effects between these two factors were observed in serum non-esterified fatty acids and chromium content. The muscle chromium content also affected by chromium source and displayed interaction of source and nanoparticle size. In conclusion, chromium supplementation could increase feed intake and average daily gain, serum and longissimus muscle chromium content, as well as reduce back fat thickness of pigs. In addition, nanoparticle organic trivalent chromium could increase chromium absorbability and decrease serum non-esterified fatty acids concentrations. Organic form was better than inorganic form in chromium absorbability, serum and longissimus muscle chromium content and average back fat thickness.