In continuation of our studies on the use of pig manure in ruminant feeding, the present paper is concerned with the investigation of the effects of solids from semi-liquid pig manure as ration components on the crude nutrient and amino-acid contents of the longissimus dorsi muscles of bulls, heifers and calves from experimental and control groups each including 6 animals. There was no difference in the crude protein, pure protein and crude ash contents between the control and the experimental groups. On the contrary, the data on dry matter and crude fat in the longissimus dorsi muscle were significantly lower in the experimental animals than in the control animals. This difference is explained by the fact that the energy content of the experimental ration (containing solids from semi-liquid pig manure) is lower than that of the standard ration. The results obtained from the analysis for 17 amino acids show that the change in amino-acid content of the muscle protein is not determined by the use of solids from semi-liquid pig manure.