PRODUCCIÓN DE LECHE EN VACAS HOLSTEIN ALIMENTADAS CON DIETAS SUPLEMENTADAS CON FUENTES ORGÁNICAS E INORGÁNICAS DE COBRE Y ZINC: REVISIÓN SISTEMÁTICA Y META-ANÁLISIS

<p><strong>Background</strong>. Preventing trace mineral deficiency in Holstein cows has a high impact on production, health, and reproduction. Inorganic sources of trace minerals are generally used because they are more economical compared to organic sources. <strong>Objective</strong>. A meta-analysis will be performed to determine the effect of including organic copper (Cu) and zinc (Zn) in the diet on milk production and the composition of Holstein cows. <strong>Methodology</strong>. Data were obtained from fourteen refereed scientific studies published between 2012 and 2023. The effect was determined by standardized mean difference (SMD) between the experimental treatment (Cu and Zn from organic sources) and the control treatment (Cu and Zn from sulfates). <strong>Results</strong>. The inclusion of organic Cu and Zn in the diet of cows did not significantly influence (P>0.05) milk production in Holstein cows. Feed intake and milk protein and fat percentages were not affected either. <strong>Implications</strong>. The study focused solely on measuring the effect on productive behavior and milk quality in Holstein cattle. However, minerals play a preponderant role in the correct functioning of the immune system of animals. Conclusion. The results indicate that organic and inorganic Cu and Zn sources can be used without affecting the performance of dairy cows.</p>