[Use of peroral DL-methionine in the prevention and treatment of ketosis in highly productive cows].

Pregnant cows in the dry period were given methionine at the rate of 0.5 cent of the dry matter of the ration 20 days before parturition. It was shown that such animals manifest no ketosis and other disturbances in the liver. High-producing, lactating cows that were offered DL-methionine orally at 0.6 per cent in the first 90 day of the lactation period did not likewise develop ketosis and other liver troubles, while animals that were deprived from this amino acid were affected up to 10 per cent. The blood levels of sugar, ketone bodies, total lipids and protein, bilirubin, SGOT, SGPT, LDH, and aldolase were influenced positively by the administration of methionine to high-producing cows. The total amount of amino acids in the blood of lactating cows rose, methionine reaching 80 per cent above the ordinary level when diets containing synthetic methionine were fed to the animals.