Testing of vitamin providing of growing and fattening pigs fed low-protein diets with additives of amino acids
 The trial was performed on 48 crossbred pigs which were assign to 3 groups, 16 pigs each, fed diets with decreased level of сrude protein (growing pigs: grs. 1, 2 - 12%; gr. 3 - 15%; fattening pigs: period I: grs. 1, 2 - 11,4%; gr. 3 - 13.5%; period II: grs. 1, 2 - 10.7%; gr. 3 - 11,8%) and additives of essential amino acids. The availability of thiamine was estimated by the ratio pyruvate/thiamine in blood, urine and liver. On the basis of thiamine test on blood and urine, the deficit of thiamine was indicated in gr. 3. of growing pigs and in fattening pigs during period I. The significant shifts in the level of fat soluble vitamins (A, E) and in peroxide lipids oxidation in muscle and fat tissues were not indicated. The level of thiobarbiturate reactive complexes in blood plasma was decreased in relation to amelioration of amino acid nutrition, possibly, as a result of neutralization of malonate aldehyde after its oxidation in liver. In pigs of gr. 2 the decreased haemolysis of erytrocites and increased level of α-tocopherol in liver were indicated. The data obtained suggest that providing of pigs with vitamin B1 may be estimated by thiamine test on blood with introduction of safety coefficient of 1.15 -1.20 for period II of fattening and 2.0 for growing and period I of fattening.