[The course of rumen fermentation during alkalosis in cows]

The aim of the study was the investigation of rumen fermentation during alkalosis in cows. The study comprised some parameters of rumen fermentation, such as: pH, ammonia and volatile fatty acids (VFA) levels, also relationship between VFA, numbers of population of protozoa and bacteria, total production of gases in vitro particularly CO2 and CH4, amounts of lactic and total protein in rumen fluid and non-glucogenic/glucogenic ratio (NGGR) in the VFA mixture. On the basis of obtained results the amounts of fermented hexose, cell yield, ATP produced and hydrogen utilization were calculated. During alkalosis there was observed significant fall of VFA production, especially acetic and butyric acids, also lower production of gases, particularly CH4--probably as a result of selective reduction of methanogenic strain bacteria. The levelling of value of rumen pattern of fermentation occurred after the beginning of lactation probably as a result of metabolism products excretion together with milk.