[Use of proteins in the feed mixture in early weaning of pigs].

Eighty-three piglets weaned at the average age of 28, 27 and 25 days were subjected to three trials to compare the effectiveness of the use of complete feed mixtures for early-weaned piglets (COS 1 and COS 2) and experimentally prepared mixtures lower in protein and higher in energy, in some cases with an addition of carbadox. In the first 14 days after weaning the piglets fed the mixtures with 90 to 95 g less nitrogen compounds in kg had the same body weight gains, higher feed consumption, and 20% lower consumption of nitrogen compounds per kg of gain than had the piglets given the COS 1 mixture. In the subsequent period of six to thirteen days, the production data demonstrated the economic effectiveness of the use of the experimentally prepared mixtures (the condition was that the level of nitrogen compounds did not decrease to 152 g per kg). The improvement of protein conversion through an increase in the ratio of digestible energy to feed protein by 50%, as compared with the COS 1 mixture at the nitrogen-compound content of 200 g per kg, and the possibility of further reduction in nitrogen compound level after 14 days from weaning, indicate the way how to change the system of nutrition in early-weaned piglets. The high-protein commercial mixture, used to-date, causing high uraemia in the piglets, is not suitable, as demonstrated by physiological, health, and particularly economic data.