Effect of supplemental levels of chromium picolinate on the growth performance, serum traits, carcass characteristics and lipid metabolism of growing-finishing pigs

This study investigated the effect of chromium picolinate supplementation on growth performance, carcass characteristics and lipid metabolism of growing-finishing pigs. Sixty Landrace × Yorkshire × Duroc (LYD) pigs with a mean initial body weight of 46.65 (s.e. 6.72) kg were randomly allocated into three groups with two replicates. They were supplemented with 0 , 200, or 400 μg/kg (ppb) chromium in the organic form of chromium picolinate for 90 days. Supplementation with chromium picolinate in the pigs' ration improved their growth performance, enhanced average daily gain (P < 0.05.), and increased their food consumption, especially in the 200 ppb group (P < 0.05). Chromium picolinate supplementation also improved carcass characteristics, as the average back fat thickness was reduced and the loin-eye area was enhanced (P < 0.05). The serum chromium concentration in the chromium picolinate supplemented groups was approximately twice that of the controls (P < 0.05). Supplementation with chromium also markedly reduced serum total cholesterol, triacylglycerol (TG) and urea concentrations in the pig serum (P < 0.05). Serum insulin was significantly decreased in the 400 ppb group, while serum glucose was decreased in the 200 ppb group (P < 0.05). Very low density lipoprotein (VLDL) was reduced and low density lipoprotein (LDL) was increased in the chromium supplementation group. Meanwhile, the high density lipoprotein-cholesterol and VLDL-cliolesterol were markedly increased, while LDL-cholesterol was significantly diminished (P < 0.05) in the 200 ppb group. The adipocyte diameter and volume in the chromium-supplemented groups tended to be larger than in the control (P = 0.07). In vitro studies indicated that incorporation of [u, ¹⁴C]glucose into total lipids (P < 0.05.) was increased by chromium supplementation. However, there were no lipolysis differences among the groups (P > 0.05). The carcasses of the pigs that received the chromium supplemented ration contained less oleic acid (C18 : 1) and total unsaturated fatty acids (P < 0.05). On the other hand, the total saturated fatty acid content was higher than that of the controls (P < 0.05). Results in this study demonstrate that chromium picolinate supplementation in pigs has several beneficial effects.