Feeding strategies to improve the nutritional value of pork and at the same time reduce the environmental burden were examined on three pig farms representing single-feed, two-phase and multi-phase feeding systems. The experimental feed was supplemented with selenium, vitamin E and crushed linseed. Furthermore, the protein content was reduced. Fattening runs with common feed served as control. The experimental feed did not consistently affect daily weight gains, but feed consumption increased and feed conversion was impaired in most of the runs. Carcass composition was impaired only in the single-feed system, as evidenced by decreased loin muscle diameter and increased backfat thickness. The lean meat content of pigs in the multi-phase system (reduction in weekly stages from 155 to 125 g crude protein per kg feed) did not decrease, but intramuscular fat content increased, which may indicate a slight under-supply of protein. Overall, the reduction of protein in the feed hardly improved protein efficiency (i.e. protein retention/excretion).
Good fattening results despite reduced crude protein content in the feed