Protein deposition and loss are the results of the small
difference between protein synthesis and protein degradation
(Simon, 1989). An increase in protein deposition may be
achieved either by increasing the rate of protein synthesis or
by decreasing the rate of protein breakdown. In addition, if
both rates increase, protein deposition may be enhanced if
synthesis increases more than the breakdown. Similarly, even
if both rates decrease, protein deposition may be increased if
the synthesis rate decreases less than the breakdown rate
(Krawielitzki et al., 1996). CS supplementation did not change
the rate of protein synthesis, however, it decreased protein
breakdown rate, thus leading to an increase of 0.54 g N/kg
W0.75 in protein per day. The results suggest that dietary CS
supplementation increases protein retention by decreasing
the rate of protein breakdown. According to the body weight
and average daily gain in the nitrogen balance trial, the
average daily net protein gain for 0, and 70 mg/kg CS
supplementationwere 16.44 and 26.28 g N, respectively. They
were quite close to the results from the nitrogen balance trial,
which were 16.23 and 26.42, respectively.
Determining the protein turnover in finishing pigs would
be useful in defining the effects of metabolic modifiers on
protein accretion and refining amino acid requirements. This
should allow better formulation of nutritional support for
growth. In this study, dietary CS supplementationwas studied
specially through ad libitum intake. As for the effect of CS
itself on growth performance and protein metabolism, pairfeeding
will be considered in the future.
5. Conclusions
Dietary CS supplementation may improve growth performance
in finishing pigs. Protein deposition is increased after
dietary CS supplementation. This increase is caused by a
decrease in protein breakdown.