Effects of Copper Sulfate and Encapsulated Copper Addition on In Vitro Rumen Fermentation and Methane Production

Copper is a microelement crucial for the proper functioning of animals’ metabolic processes. The function of copper in rumen fermentation processes and methanogenesis is not well analyzed. The aim of the study was to evaluate the different types of copper supplement, their rumen decomposition and effect on in vitro ruminal fermentation as well as methanogenesis. Two different copper additives were used in the experiment: CS—copper sulfate (CuSO 4 × 5 H 2 O)—and EC—encapsulated copper (tribasic copper chloride and copper sulfate enclosed within a polysaccharide polymer coating). A total mixed ration without copper additive was used as a control (C). In vitro rumen fermentation was conducted, and fermentation profile, gas production and methanogenesis were evaluated. After 24 h of fermentation, the amount of copper in the rumen fluid was significantly higher in the CS group. EC was protected against rumen degradation to a greater extent. The type of used copper supplement affects rumen fermentation. However, the effect on methanogenesis is ambiguous. CS supplement increases rumen gas production but does not affect methanogenesis. The obtained results suggest that the EC supplement may reduce the risk of low-fat milk and may improve the economic indicators of milk production. An in vivo experiment is necessary to compare the obtained in vitro results with animal productivity.