Meta-Analysis of the Effects of Organic Chromium Supplementation on the Growth Performance and Carcass Quality of Weaned and Growing-Finishing Pigs

SIMPLE SUMMARY: During pig production, organic chromium is usually added to the feed to supplement the chromium needed for pig growth and metabolism. However, different types of organic chromium have different effects on the addition period and dosage. Therefore, the purpose of this study is to analyze the effect of adding organic chromium in pig feed by means of meta-analysis. The results show that organic chromium can improve the average daily gain and average daily intake of pigs. At the same time, the effect of adding in the weaning stage is better than that in the growing and finishing stage. ABSTRACT: 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.