Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Animal, Dairy, and Veterinary Sciences


Jay O. Anderson


An attempt was made to determine the effect of overall indispensible amino acids (IAAs} level on growth rate and efficiency of broiler chicks. There were two overall levels: the low (8.33% IAA, 17.6% CP containing all IAAs at the minimum requirement found in preliminary studies), and the high (10.77% IAA, 21.5% CP with IAAs increased by 28%). Both diets contained 13.7 Mega joules ME (3277 Kcal) per kilogram.

These two diets along with other variations of the two diets were fed to Hubbard chicks. Growth rate , with the low IAA diet was as good as with the high, but feed efficiency was significantly better for the high. When one of the IAAs was reduced from the higher to the minimum estimate, feed efficiency was better than the low overall diet.

Two additional diets with the low levels of IAAs and dispensible amino acids increased were fed to male Hubbards. Protein level was increased by the addition of DAAs but did not improve either growth rate or feed efficiency. Therefore, it was concluded that feed efficiency was not improved by increasing DAAs alone.