title: Tryptophan and threonine requirements of fingerling channel catfish.
abstract: Growth studies, utilizing a 24% crude protein diet containing an amino acid pattern similar to whole egg protein, indicate that the tryptophan requirement for fingerling channel catfish (Ictalurus punctatus) is about 0.12% of the diet (dry weight basis) or 0.5% of the dietary protein. Similar studies indicate that the threonine requirement for the same fish is about 0.53% of the diet (dry weight basis) or 2.21% of the dietary protein. The dietary requirement of threonine was confirmed by serum free threonine analysis. A marked increase in serum free threonine occurred at a dietary threonine level of approximately 0.5% of the diet. None of the gross pathological changes previously reported for tryptophan deficiency in sockeye salmon and rainbow trout were observed in channel catfish.
mesh_terms: D000596:Amino Acids; D000818:Animals; D001835:Body Weight; D004032:Diet; D005399:Fishes / Q000378:metabolism*; D009751:Nutritional Requirements; D013912:Threonine / Q000008:administration & dosage / Q000097:blood*; D014364:Tryptophan / Q000008:administration & dosage*
chemical_list: D000596:Amino Acids; D013912:Threonine; D014364:Tryptophan