Administration Of Monensin Research Articles

Ultrastructural changes of hepatocyte organelles induced by chemicals and their relation to fat accumulation in the liver.

Fatty liver was induced in the rats shortly after administration of cycloheximide, ethionine, orotic acid, monensin or colchicine. It was strongly suggested that derangements in one or more of the hepatic lipoprotein metabolic steps, which occur at the levels of endoplasmic reticulum, Golgi apparatus and secretory vacuoles lead to an accumulation of triglyceride within hepatocytes.

Prevention of lactic acidosis in cattle by lasalocid or monensin.

Intraruminal administration of lasalocid or monensin (1.3 mg/kg body weight) effectively prevented in glucose- or corn-induced lactic acidosis in cattle. Administering the antibiotics for 7 days before experimentally inducing acidosis with corn (27.5 g/kg body weight), effectively prevented acidosis, while 2 days' were sufficient to prevent glucose-induced acidosis (12.5 g/kg body weight). The different responses observed in the two trials probably stemmed from the difference in amounts of carbohydrate used to induce acidosis. Antibiotic-treated cattle had higher rumen pH values and lower L(+) and D(-) lactate concentrations that control cattle that received no antibiotics. Ruminal VFA in control cattle decreased, while total VFA and the molar proportion of propionate increased in antibiotic-treated cattle after grain engorgement. Control cattle exhibited classic signs of acidosis, such as lowered blood pH; increased blood lactate, particularly D(-) isomer; hemoconcentration, and depleted alkali reserve with a pronounced based deficit. Antibiotic-treated cattle exhibited no signs of systemic acidosis.

Investigations concerning the use of the rumen fermentation regulator monensin in feeding fattening bulls

In two digestion experiments with wethers and seven feeding experiments with 198 fattening bulls with rations rich in (greater than 55% of the dry matter intake from roughage), the influence of the antibiotic monensin on the digestibility of the ration, on rumen-physiologic characteristic values and on fattening and slaughtering results was investigated. The digestibility of the organic matter and the crude nutrients was not significantly influenced by the use of monensin (20 mg/kg dry matter). The administration of 200 mg monensin per fattening bull and day resulted in an increase of the molar concentration of propionate in the rumen fluid by 9.7 mol%, the concentration of acetate and butyrate decreased by 7.3 resp. 2.8 mol %. On an average of the seven experiments the intake of dry matter was diminished by 5.1% through the use of monensin, the live weight increase remained almost unaffected (3.0% additional increase), feed and energy requirement per kg live weight were improved by 7.9%. The fattening results do not always correspond in the various experiments. The results of the dressing of the carcass, the composition of the carcass and the quality of the meat remained unaffected by the administration of monensin.