Bioactive Peptides application in animal feed is a recent breakthrough and a branch from the advances of Biotechnology. The 1970's research resulted in new knowledge regarding fish meal and fish soluble impacts on animal growth, hatch rate, and other performances. Scientists were puzzled with the discovery that stemmed from this research that crystalline amino acids feed was under performing intact protein feed. They speculated that this finding had some relation with the peptide bond. The advancement in research of peptide absorption in the 1980's and peptides’ biological and physiological functions in the 1990's has engendered a new area of research in animal nutrition. Research reports from Europe, Japan and America have uncovered various peptide molecular structures and their functions.

Most small peptide molecules aid in increasing free amino acids absorption, feed intake and improving taste. Larger peptide molecules tend to possess biological and physiological functions, such as stimulating the immune system, increasing digestive enzyme synthesis and secretion, reducing GI motility, blood pressure, and pain sensation, relieving stress, anti-microbial, etc. A long single chain peptide can re-arrange itself so that it merges with a cell membrane and forms a channel for transporting nutrients or hormones in and out of cells. One of the Bioactive Peptide’s Mode of Actions is that it can act as ligand and bind with receptors on a cell membrane to trigger an appropriate biological response.

Certain peptide molecules tend to be very stable. They can resist peptidase and protease digestion. They are also acid and temperature stable. Different protein sources and processing methods can generate different peptides. Plant proteins are hydrolyzed to free amino acids and Nutritional Peptides while animal proteins are hydrolyzed to higher concentration of Bioactive Peptides. Most animals tend to absorb a peptides-amino acids mixture faster and in a higher amount than free amino acids alone. It is proven that amino acid absorption requires higher energy consumption and the mechanism is saturable while peptide absorption requires less energy and via different absorption carriers and channels. When peptides are presence, they reduce the competition for absorption carrier by FAA. There is also a strong indication that peptides could be absorbed through diffusion.