Effects of Oregano (Oreganum Onites L.) Aromatic Water on Rumen Microbial Fermentation of Holstein Calves

Abstract

The study aimed to determine the effects of the addition of aromatic oregano water (AOW) on rumen fermentation of Holstein calves. For this purpose, 20 Holstein calves were divided into four groups (n = 5) and fed with three different doses of AOW (1, 1.5, and 2%). The experimental groups were formed as follows; the control group (CNT): milk + starter; G1: 1% AOW supplemented milk + starter; G2: 1.5% AOW supplemented milk + starter; G3: 2% AOW supplemented milk + starter. The rumen fluid was taken from the oesophagus at 60 days of age with the aid of a rumen probe. In acetic acid (AA), propionic acid (PA), and butyric acid (BA) except for total volatile fatty acid (TVFA) (P < 0.05), the numerical differences between the means of the groups were not found statistically significant. The rumen pH values of the groups were not affected by the addition of AOW. Likewise, the difference between the total bacteria and the numbers of protozoa, Entodinum, Diplodinium, Isotrichia, and Daystrichia were not statistically significant. The results of the study showed that the addition of AOW did not have a negative or positive effect on rumen fermentation of the calves.