Effect of graded high-energy-level protein supply on fattening performance and retention and utilization of feed energy, protein and amino acids in female fattening swine. 4. Nitrogen and amino acid content in carcasses and parts

Abstract

The slaughtering and cutting up of 7 (6) female pigs in each of 3 groups (live weight approximately 113 kg) fed on approximately 80, 100 and 120% protein (lysine) of the norm as well as the determination of nitrogen and amino acids in the individual parts of the body had--in comparison to 6 reference animals (live weight approximately 36 kg) treated in the same way at the beginning of the experiment--the following results: In the course of growth the quota (in % of the slaughter weight) of bacon, belly fat + intestinal fat tissue is more than doubled; the relative quotas of bones, skin + ears, bristles + claws, blood and entrails, however, decrease. The total meat quota is 54% and remains relatively equal independent of the live weight. The N-quotas (in % of the empty body-N) of muscle and fat tissue and of the skin increase in the course of fattening, those of bones, useable organs and offal decrease distinctly. At the end of fattening the muscle protein of the animals amounted to 59% of the empty body protein and to 87% of the carcass protein. The amino acid content (g/16 g N) hardly changes in the individual parts during growth; the percentage amino acid distribution follows the weight-and N-distribution. The lysine content of the edible parts of the carcass is 8.4 g/16 g N. The chosen grades in the protein (lysine) supply of the test animals did not result in any significant changes with regard to the qualitative parameters (protein and amino acid content of the valuable and less valuable parts of the body as well as their percentage distribution in the empty body). The quantitative parameters (live weight gain, protein (amino acid) retention per day) are diminished in approximately the same relation as the insufficiency of the alimentary supply; by excessive supply, however, they do not significantly increase. The results are compared with corresponding data from literature and discussed.