[Influence of sex and live body mass on the true protein and amino-acid digestibility of various animal feeds in pigs. 1. Comparative studies between barrows and female pigs].

Growing barrows and female pigs of 3 liveweight ranges (20-30 kg, 50-60 kg, 80-90 kg) were used to study the true digestibility of protein and essential amino acids from 4 cereal species and 4 high-protein concentrate using the fecal analysis method and regression techniques. No significant differences were found between the females and the barrows in the true digestibility of the protein and most of the amino acids from the protein carriers under study. In the 3rd liveweight range, the true digestibility of some amino acids of the cereals proved somewhat lower in tendency with female animals. In comparison with the true digestibility of protein, in the cereals under study that of lysine gave significantly lower, and that of cystine, arginine, phenylalanine and histidine significantly higher values. The relative values (protein = 100%) were 85.0, 110.6, 106.8, 106.5 and 105.5 for lysine, cystine, arginine, phenylalanine and histidine, respectively. The true digestibility of the remaining amino acids is comparable to that of protein.