[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 9. The effect of various levels of energy and protein nutrition on the performance and feed expenditure of fattening pigs]. / Gemeinschaftsuntersuchungen zur Präzisierung des Energie- und Proteinbedarfs für Mastschweine. 9. Mitteilung. Einfluss unterschiedlicher Niveaus der Energie- und Proteinernährung auf Leistung und Futteraufwand bei Mastschweinen.

In the scope of a joint international experiment, 2 scientific feeding experiments were carried out in combination with measurings of the metabolism for the determination of the digestibility and the N-balance with hybrid pigs of modern genetic origin in the fattening period between 30 and 100 kg live weight. In the first experiment with isocaloric feeding the influence of 3 levels of protein supply (18, 16 and 14% crude protein in the first fattening period and 16, 14 and 12% crude protein in the second fattening period) on the fattening performance and the expenditure of feed, protein and energy per kg live weight gain and in the 2nd experiment with equal crude protein supply per animal and day the influence of 3 levels of energy supply (100 : 85 : 70%) on fattening performance and expenditure were tested. In addition to that, the composition of the carcass was ascertained of a total of 51 animals. The average live weight gain in the 3 variants and over the complete fattening period between 30 and 100 kg in experiment 1 amounted to 772 g, 753 g and 687 g and in experiment 2 to 778 g, 713 g and 583 g. The best fattening performance was achieved with the highest energy and protein supply, and an energy supply reduced by 15% nevertheless resulted in fattening performance 753 and 713 g resp. per animal and day. The expenditure values are discussed; a detailed evaluation is given in the 10th contribution to this series of publications on the total results of this joint international experiment. The carcass analysis shows the tendency of a decreasing protein content in the carcass caused by a decreasing protein supply and an increasing fat and energy content whereas a decrease of the energy supply has no effect on the protein content but a distinct effect with regard to the decrease of the fat content of the carcass caused by the decreased energy supply.

[Joint research on the precise determination of the energy and protein requirements of fattening pigs. 10. Comparative evaluation of the research for the precise determination of the energy and protein requirements of fattening pigs]. / Gemeinschaftsuntersuchungen zur Präzisierung des Energie- und Proteinbedarfs für Mastschweine. 10. Mitteilung. Vergleichende Auswertung der Untersuchungen zur Präzisierung des Energie- und Proteinbedarfs für Mastschweine.

Institutes from 5 CMEA countries took part in complementary joint investigations in order to ascertain the variance in energy and protein requirement and parameters of nutrient and energy metabolism with such fattening pigs as test animals as characterise the prospective breeding development in each of the countries and in order to establish the bases for the critical revision of the norms of energy and protein requirement for fattening pigs and, if necessary, their more precise determination. The most important conclusion drawn from the comparative assessment of the results presented in 9 articles is that due to wide variations in the energy and protein requirement values between the individual investigators as well as within the institutions themselves, norms of energy and protein requirement for fattening can only be adopted between countries when adequate investigations under the specific conditions of the individual countries justify this.