The effect of reduced dietary protein level on the activity of transketolase and glutathione reductase in pig erythrocytes

Abstract

The effect was investigated of decreased protein level in a food ration on covering the requirements for vitamins B1 and B2. Two feeding experiments were conducted, each on 32 fattening pigs of Polish Landrace breed. The activity of transketolase and glutathione reductase in erythrocytes and vitamin B1 and B2 level in blood and liver were determined. It was shown that a reduction of the diatery protein level by 25% caused a decrease of thiamine utilization by pigs. It indicates the necessity of a dietary supplementation with a synthetic vitamin B1 preparation in such a condition. A reduced activity of glutathione reductase, indicating a riboflavin deficiency, was observed only when the low protein diet was additionally deprived of a vitamin-mineral premix containing a fodder B2 preparation. Reduction of the dietary protein level by 25% was not associated with the risk of riboflavin deficiency, provided that the ration was supplemented with a standard dose of synthetic vitamin B2.