Determination of in vitro ruminal fermentation levels with antioxidant and antimicrobial effects of lavender hay and aromatic water

The effects of lavender (Lavandula intermedia) hay and aromatic water, an aromatic plant used in alternative health for many years, on in vitro rumen total gas production, methane gas production, metabolic energy, organic matter digestion, and volatile fatty acids were investigated. Lavender hay was considered an alternative to wheat straw and was substituted for wheat straw in the diet. Lavender hay was added at levels of 0, 25, 50, 75, and 100% to the diet. Additionally, aromatic water was added to the rumen fluid at levels of 1, 2, and 4 mL. The phenolic compound content and antioxidant capacity of lavender hay were higher than those of lavender aromatic water. While lavender hay significantly reduced methane (CH4) production (P<0.05), aromatic water significantly reduced total gas production (TGP), CH4, metabolic energy (ME), and organic matter digestion (OMD) (P<0.001). Neither lavender hay nor aromatic water significantly affected the production of total volatile fatty acids (TVFA) in the in vitro fermentation fluid. However, the addition of hay at levels of 75% and 100% tended to increase the concentrations of acetic (AA), propionic (PA), and butyric acids (BA), while 4 mL of aromatic water only tended to increase the concentration of PA. The study suggests that the addition of lavender hay and aromatic water to ruminant diets could be effective in reducing methane emissions and could be used to mitigate the environmental impact of livestock. However, when using these additives, the possibility of negatively affecting nutrient digestion in the rumen and excreting the energy of the ration in the feces should not be ignored.