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A Short History of Ideal Protein
The Ideal Protein concept, defined as an ideal pattern of amino acids is one that meets requirements for the sum of metabolic processes with minimal excesses, is applied in much of the monogastric feed formulation done today. This concept, however, is rooted in close to 80 yr of research, with work and debate continuing today. The initial concepts of an ideal protein, a profile of amino acids that most closely resembled an intact protein such as whole egg, were revised to a profile of amino acids that most closely met the requirements of an animal for maintenance and growth through construction of a purified crystalline amino acid diet for young chicks. The elucidation of non-specific amino nitrogen requirements, interconversion among amino acids, and antagonisms between amino acids, further refined the ideal protein concept. The initial implementation of the Ideal Protein for commercial livestock production occurred in 1981, when the British Agriculture Research Council proposed an ideal protein for swine that presented essential amino acids requirements as a percentage of Lysine, with is first-limiting amino acid for protein deposition in most swine diets. From this point, much work was done to estimate the ratios of essential amino acids relative to Lysine that maximized performance. Much work has continued to focus across multiple physiological states, from growth to pregnancy and lactation. The impact of immune challenge and nutrient composition of diets have been studied to determine their role in ideal protein requirements. This concept has been applied across livestock species as well as companion animals.
Keywords: History, Ideal protein, Pigs