Trace mineral supplementation via organic or inorganic sources for beef cattle during preconditioning and feedlot receiving: A systematic review and meta-analysis.

To mitigate the effects of stressors during the preconditioning and feedlot receiving phases of the United States beef industry, producers may opt to utilize trace mineral supplementation in organic (OTM) or inorganic (INR) forms. However, research surrounding the effects of this supplementation on average daily gain (ADG) or morbidity are variable. Therefore, a meta-analysis further analyzing the effects of OTM supplementation compared to INR supplementation on ADG and morbidity with differentiation based on production phase receiving supplementation, apparent risk classification, length of time receiving supplementation, the usage of dietary antibiotics, and year of study was conducted. Studies were collected via two independent literature searches and from Zinpro Corporation utilizing PICOT search parameters relevant to study outcomes of interest, resulting in 20 studies. Data extracted from these studies included treatment means, standard error of the means, standard deviations, P-values, and odds ratios and these data were analyzed within the meta package of R (v. 4.3.2). Overall, supplementation with OTM increased (P = 0.01) ADG while having no effect (P = 0.92) on apparent overall morbidity. Furthermore, no differences in ADG (P = 0.66) were found when comparing OTM vs. INR supplementation during preconditioning or feedlot receiving. Average daily gain was similar (P = 0.35) between low- and high-risk classes, similarly, apparent overall morbidity outcomes were similar (P = 0.18) for both risk classes. Additionally, length of time receiving supplementation, either ≤ 30 d or > 30 d, did not result in differences ADG (P = 0.62) or apparent overall morbidity (P = 0.14). The inclusion of dietary antibiotics had similar results across studies for both ADG (P = 0.27) and apparent overall morbidity (P = 0.27). Finally, ADG was similar (P = 0.91) between class of study date, either current (2005-2024) or previous (prior to 2005). In conclusion, OTM supplementation may increase cattle ADG during stressful periods. However, apparent overall morbidity was not affected by OTM supplementation compared to INR supplementation. Collectively, this study highlights circumstances where supplementing OTM could be more beneficial to animal performance and health.