Amino Acid Supplementation of Opaque-2 Corn Diets for Growing Rats

Publisher Website
Google Scholar
Abstract
Four trials involving 210 weanling male albino rats were conducted to determine the extent of deficiencies of amino acids in opaque-2 corn and to reevaluate the needs of the growing rat for several of the essential amino acids. The basal diet contained 9.2 to 9.4% protein equivalent and was characterized by a lack of gross excess of any essential amino acid and a ratio of nearly 1:1 of essential-to-nonessential amino acid nitrogen. Excellent daily gain, gain/feed and protein efficiency ratio (nitrogen retention in one trial) were obtained when the diet containing 89.5% oaque-2 corn was supplemented with 0.1% L-isoleucine, 0.18 to 0.35% L-lysine, 0.2% DL-methionine, 0.12% L-phenylalanine, 0.14% L-threonine and 0.08% L-valine. Final dietary levels of 0.36% isoleucine, 0.70% lysine or less, 0.40% methionine + cystine, 0.59 to 0.65% phenylalanine + tyrosine, 0.43% threonine and 0.54% valine appeared to be adequate for the growing rat. These results indicate that currently accepted requirements of the growing rat for isoleucine, lysine, methionine + cystine, phenylalanine + tyrosine and threonine may be slightly excessive.
Keywords