Many factors influence the effects of exogenous organic chromium (EO-Cr) on the growth performance and carcass qualities of weaned and growing-finishing pigs, such as pig growth stages, types of EO-Cr, period of supplementation, and farm management. However, it is challenging to comprehensively consider all factors in one study. To solve this problem, we searched all relative literature published from 1 January 2000 to 1 January 2023, to systematically analyze and review the effects of EO-Cr on pig growth performance and carcass qualities via meta-analysis. Thirty-five papers were filtered and analyzed, which involved 4366 pigs. The results showed that, for weaned piglets, EO-Cr diets significantly increased the average daily gain (ADG, p < 0.001) and average daily feed intake (ADFI, p = 0.022) but reduced the feed-gain ratio (p = 0.004). In addition, for growing-finishing pigs, EO-Cr supplementation significantly increased the ADG (p < 0.001), carcass lean ratio (p = 0.020), and loin muscle area (p < 0.001), but had no significant effect on the ADFI (p = 0.071), feed-gain ratio (p = 0.692), dressing percent (p = 0.989), or back fat thickness (p = 0.142). Moreover, the effect of EO-Cr was greater in weaned piglets than in growing-finishing pigs. In terms of the dose effect of the supplement, chromium nicotinate is the most suitable EO-Cr type for weaned piglets with an optimal dosage range of 0.125-0.150 mg/kg. On the other hand, chromium picolinate is the most suitable EO-Cr type for growing-finishing pigs with an optimal dosage range of 0.250-0.300 mg/kg. In conclusion, EO-Cr supplementation is beneficial for enhancing the growth performance and carcass qualities of both weaned and growing-finishing pigs.
Keywords: carcass quality; exogenous organic chromium; growth performance; meta-analysis; pigs.