Metabolic effects of liquid protein.

In the first experiment, the liquid protein product (LP) tested would not support growth in rats when fed at the 8% protein level in an otherwise nutritionally adequate diet. The product was composed of an imbalanced mixture of amino acids which could not be used optimally for protein synthesis and which resulted in appetite depression. Total plasma nonessential amino acids increased significantly in the rats receiving LP, while total plasma essential amino acids were not significantly different.

Protein quality and the cost of selected commercial protein supplements.

The biologic value and the cost of three commercial protein supplements were compared using casein as the control. Each product was fed to rats as the sole protein source supplying 10 percent of the energy in a semipurified diet. Nonfat dry milk was equal to casein in PER, but the PERs of low-fat soy powder and high-protein supplement were significantly lower than the PER of casein.

The biological activity of vitamin B6 analogs in the rat.

The effects of three vitamin B6 analogs were studied in young adult and weanling rats. The 2-ethyl analog was the most active. It produced higher growth rates, an average feed efficiency equal to the control and elevated liver glycogen levels.