Plasma amino acid changes in Tilapia nilotica fed a casein and a corresponding free amino acid diet.

Abstract

Starved Tilapia nilotica were fed a casein diet and an amino acid diet of similar composition. The change in concentrations of plasma-free amino acids of Tilapia at 0 , 2, 4, 8, 12 and 24 hours after administering the two diets was examined.With respect to the casein diet , all plasma-free essential amino acids attained their maximal values at 4 hours after feeding, and then declined to the fasting levels within 24 hours.With the amino acid diet, all plasma-free essential amino acids peaked at 2 hours, and returned to their fasting levels within 4 to 8 hours.Free non-essential amino acids showed unique patterns of change in the plasma of Tilapia after both the casein diet and the free amino acid diet were administered.

Poor utilization of dietary free amino acids by white sturgeon

“…In the common carp, Plakas et al (1980) reported a more rapid absorption of dietary IAA when fed amino acid mixtures as compared to carp fed intact protein. A similar situation also has been reported for the Nile tilapia, Tilapia nilotica (Yamada et al 1982). Unlike the common carp, all dietary free IAA were absorbed simultaneously from the intestine of Nile tilapia.…”

“…Furthermore, in common carp, all dietary IAA did not reach peak levels simultaneously in the plasma after feeding the amino acid diet (Plakas et al 1980). This phenomenon was not observed in Nile tilapia (Yamada et al 1982) or in this study.…”

“…Experiments on postprandial changes of plasma free amino acids have been carried out to investigate the reason for the inability of the amino acid diet to support normal growth of various fish species (Yamada et al 1982;Plakas et al 1980;Mural et al 1987). The overall time and pattern of appearance of plasma IAA in the sturgeon force-fed purified diets containing intact protein or amino acid mixtures were similar to those of warmwater fish species.…”

“…In common carp (Plakas et al 1980), Nile tilapia (Yamada et al 1982), and channel catfish (Wilson et al 1985), plasma IAA levels peaked within 4 to 12 h after feeding purified diets with intact protein, and returned to fasting levels within 24 h. In contrast, maximal plasma IAA levels in Nile tilapia and common carp fed amino acid mixtures were reached within 2 h and 2-4 h, respectively, and declined to fasting values within 16 h. Amino acids are therefore absorbed from the intestinal tract at a more rapid rate when fish are fed amino acid mixtures. Furthermore, in common carp, all dietary IAA did not reach peak levels simultaneously in the plasma after feeding the amino acid diet (Plakas et al 1980).…”

Changes in tissue and plasma free amino acid concentrations after feeding in Atlantic cod

“…Automated AA analysis of blood and tissues has frequently been used to investigate changes in free AA concentrations after feeding in fish, several studies having been done on commercially important freshwater species (Nose 1972;Plakas et al 1980;Yamada et al 1981Yamada et al , 1982Wilson et al 1985;Walton and Wilson 1986;Murai and Ogata 1990). However, little information is available regarding post-prandial changes in the free AA pools of saltwater fish, with only a few investigations on seawater adapted rainbow trout (Kaushik and Luquet 1977a, b) and sea bass (Thebault 1985).…”