Effect of genetic provenience of pigs (German Landrace, Pietrain) on parameter of protein metabolism

Within a feeding experiment using N and N-15 balance techniques the effect of genetic provenience on parameter of protein metabolism was tested in 28 growing female pigs (12 pigs from German Landrace, 16 pigs from Pietrain). The animals were fed restrictively (1.2 MJ ME/kg of metabolic body weight). In Pietrain animals the apparent digestibility of crude protein was reduced by 2.2 percentage units. However, the respective increase in fecal N was c ompletely counterbalanced by a reduced urinary N excretion. The N balance, gross utilisation of N and the protein turnover (rate of synthesis and degr adation of body protein) remained unchanged. Blood plasma contents of IGF 1 were lower in Pietrain animals than in German Landrace. Except for some mi nor fluctuations in postileal microbial N exchange there was no indication of any quantitatively significant effect of the genetic provenience on the efficiency of protein metabolism.