Trace Mineral Source Impacts Volatile Fatty Acid Profile and Rumen Trace Mineral Solubility in Feedlot Steers †

Abstract

Trace mineral (TM) supplementation in feedlot diets is a common practice in the cattle industry to prevent deficiencies and to improve animal performance. Utilizing different TM sources can alter rumen fermentation due to TM solubility in the rumen. This study supplemented TMs (Cu, Mn, and Zn) from two different sources, either sulfate (STM) or hydroxychloride (HTM), to steers consuming a high concentrate feedlot diet. No differences in nutrient digestibility were observed between TM treatments. However, we observed lower molar proportions of propionate, greater ruminal solubility of Cu, and greater binding strength of Cu and Zn toward digesta in STM-supplemented steers than HTM-supplemented steers. This study suggests that TM source impacts rumen fermentation characteristics and TM solubility in the rumen. This study also suggests that HTM supplementation can result in greater energy production and muscle deposition in animals compared to STM, which can lead to higher yield in feedlot cattle.