EFFECT OF MAGNESITE IMMISSIONS ON FERMENT ATION PROCESSES IN THE PROVENTRICULI OF CATTLE

The effect of magnesite flue dust on rumen fermentation processes in r umen-cannulated young bulls of Black-Pied breed was studied in two phy siological experiments. The daily amount of flue dust (200 g) was calc ulated by the analysis of immission fall-out per 1 m(2) soil. The test flue dust came from dust separation from electrostatic filters and it contained: MgO 54%, CaO 1,3%, Fe2O3 3,7%. The amount of magnesite flu e dust eaten by the animals did not influence their feed intake. The v alues of actual acidity remained within the span of physiological valu es in the control as well as experimental animals. We did not notice a ny increased alkalinity in the rumen environment. Although pH of the r umen content increased slightly, the differences were not significant. The level of ammoniac N was lower in animals in the experimental grou p during the whole sampling, however, significant differences (P < 0.0 1) were observed only 4.5 and 6 hrs after feeding. The VFA concentrati on did not change in the individual rime periods. We observed a transi ent moderate diarrhoea without further symptoms in the experimental an imals during the first week of the experimental period. It is a domina nt clinical finding due to the experimental stress by magnesite flue d ust.