[Lactic acid content of blood plasma in domestic swine of various breeds during physical exertion].

Lactic acid was determined by an enzymic method in plasma samples taken from 20 pigs of the German Edelschwein, German Landrace, German Saddleback and Edelschwein/Landrace crosses before, during and after being made to run on a band moving at 1.3 metres/second for ten minutes, at 10 degrees C and relative humidity of 65-75%. A special method was used to assess the degree of exertion. The lactic acid curve showed that Edelschwein and German Saddlebacks had a low regulatory capacity while German Landrace and the crossbred pigs had a large capacity. For assessing differences attributable to individuals or to breeds, the occurrence of the maximum lactic acid concentration during or after exercise was of special significance.