PARTITIONING OF PROTEIN AND LIPID DEPOSITION IN THE BODY OF GROWING PIGS

Two amounts of energy intake (12.6 and 16.3 MJ DE/day, respectively) above maintenance requirement were given to entire male pigs from 25 to 105 kg body weight. Slaughter, dissection and chemical analysis in three body fractions on 25, 65 and 105 kg live weight allowed calculation of tissue deposition and tissue partitioning in two weight ranges. On average, 57% of total protein deposition was deposited into the LEAN fraction. Moreover, 68% of total lipid deposition was deposited into the non-lean carcass parts on average. An increase in energy intake resulted in an increase in both lipid and protein deposition. Of this extra protein deposition and extra lipid deposition, 42 and 75% respectively were directed to the non-lean carcass parts in the live weight range 25-65 kg. Above 65 kg live weight, these respective percentages were 71% and 82% on average. Thus, despite the relatively low intake levels, the major part of extra tissue deposition was deposited into non lean carcass tissue. The effect of a 40 kg increase in body weight on protein and lipid deposition rates was small as compared to the effect of an extra 250 g of feed. Thus, for the used feeding regimen, partitioning of protein within the body was mainly effected by nutrition, and not by body weight. It was concluded that a nutrition induced increase in lean tissue deposition rate will be coincided with a substantial increase in body fatness. This is due to an increase in lipid deposition accompanying an increase in protein deposition. Furthermore, an increase in protein deposition enhanced the partitioning of protein to tissues other than lean.