Amino acid absorption and endogenous amino acids in the lower ileum and excreta of chicks.

Five diets containing protein levels supplying 5-35 g N/kg, and an N-free diet, were fed ad libitum to six groups of 15 chicks each, from 10 to 16 d of age. Soybean meal was the only source of protein. Diets contained magnesium ferrite as marker.

Nitrogen absorption and endogenous nitrogen along the intestinal tract of chicks.

Six groups of 15 chicks each were fed ad libitum experimental diets that contained between 0.4 and 35 g nitrogen/kg, from 10 to 16 d of age. Soybean meal was the only source of protein, and the marker was magnesium ferrite.

Apparent amino acid absorption from feather meal by chicks.

The apparent absorption values of individual amino acids from two samples of feather meal (FM) were determined in the lower ileum of chicks fed on diets containing magnesium ferrite as a marker. The average absorption values for FM amino acids were low, approximately 0.50, as compared with approximately 0.

Nutritional value of feather-meal protein for chicks.

Ileal absorption of nitrogen was determined for feather meal (FM) samples, using magnesium ferrite as a marker. Diets containing 15% FM were balanced by linear programming, using two nitrogen absorption values for FM: 55%, as found, or 85%, an average value for standard feeds. When nitrogen absorption of FM was calculated as 55%, the growth of chicks from one to three weeks of age was similar to that of the control chicks.