Effects of feeding ferric citrate on methane production and nutrient and energy balance in growing beef steers

Authors: HARTMAN, S - Iowa State University; DORNBACH, C - Texas Tech University; HANSEN, S - Iowa State University; DREWNOSKI, M - University Of Nebraska; WICKERSHAM, T - Texas A&M University; Neville, Bryan; HALES, K - Texas Tech University

Submitted to: Applied Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2026
Publication Date: 5/20/2026
Citation: Hartman, S.J., Dornbach, C.W., Hansen, S.L., Drewnoski, M.E., Wickersham, T.A., Neville, B.W., Hales, K.E. 2026. Effects of feeding ferric citrate on methane production and nutrient and energy balance in growing beef steers. Applied Animal Science. 42(3):295-302. https://doi.org/10.15232/aas.2025-02783.
DOI: https://doi.org/10.15232/aas.2025-02783

Interpretive Summary: This study was conducted to evaluate ferric citrate as a potential additive to decrease energy losses during digestion in beef cattle. At the time this study was conducted, no information was available to help understand ferric citrate’s effects on energy partitioning and nutrient balance. Our results suggest that ferric citrate could slightly decrease energy losses in beef cattle; however, it also had detrimental effects on fiber digestibility and increased nitrogen excretion that are likely to negate any benefit.

Technical Abstract: Objective: We determined the effects of ferric citrate supplementation on energy partitioning, methane production, and nutrient balance in growing beef steers. Materials and Methods: Angus steers (n = 8; initial BW = 363 ± 30.4 kg) were used in a replicated 4 × 4 Latin square design experiment. Treatments consisted of: 1) 0 mg of ferric citrate (F0; control), 2) 250 mg Fe/kg DM as ferric citrate (F250), 3) 500 mg Fe/kg DM as ferric citrate (F500); or 4) 750 mg Fe/kg DM as ferric citrate (F750). After a 16-d diet adaptation period, dietary treatment, orts, feces, and urine were collected and composited over a 5-d collection period. On day 3 of each collection period, gas exchange was measured using indirect calorimetry headboxes. Results and Discussion: Methane energy loss tended to decrease quadratically with F0 and F750 steers having greater methane energy losses than F250 and F500 steers. Subsequently, ME decreased linearly, and ME as a proportion of GE intake tended to decrease, with increasing concentrations of ferric citrate. Retained energy and retained energy as a proportion of GE intake tended to decrease linearly as ferric citrate concentration increased. In addition, fecal nitrogen excretion tended to increase as ferric citrate concentration increased. Conclusions and Applications: Collectively, these findings suggest that ferric citrate could slightly decrease CH4 energy losses at concentrations below 500 mg. Nonetheless, linear decreases in ME and retained energy suggest that ferric citrate inclusion may have detrimental effects on energy balance that limit its application in growing beef steers. Therefore, potential environmental benefits are negated by the decrease in energetic efficiency. Overall, these findings do not support the use of ferric citrate for CH4 mitigation.