The patterns of plasma free amino acids after force-feeding in rainbow trout Oncorhynchus mykiss (Walbaum) with and without dorsal aorta cannulation

Re-evaluation of Dietary Methionine Requirement by Plasma Methionine and Ammonia Concentrations in Surgically Modified Rainbow Trout, Oncorhynchus mykiss

“…The patterns of most plasma free amino acid concentrations from force-fed rainbow trout with and without dorsal aorta cannulation were similar, and the dorsal aorta cannulation did not affect the pattern of plasma free amino acid concentrations in rainbow trout (Ok et al, 2001). These results indicate that force-fed rainbow trout might recover from the stress of dorsal aorta cannulation within 48 h of the operation, and the dorsal aorta cannulation would allow repeated sampling on the same individual fish to study nutrient metabolism in the blood circulation.…”

“…Murai et al (1987) and Schuhmacher et al (1997) reported that the plasma concentrations of arginine, leucine, isoleucine, valine, phenylalanine and threonine in rainbow trout force-fed crystalline amino acids at 1% body weight (dry matter) peaked at 6-9 h and returned to the basal level at 24-32 h post feeding. Ok et al (2001) demonstrated that most of the plasma free amino acids peaked approximately 4 h after feeding, and returned to near basal level in 24 h in rainbow trout that force-fed the experimental diets after. In chicks, Zimmerman and Scott (1967) found that lysine, valine, and arginine concentrations in the plasma increased in a dose response manner when the intake of the dietary amino acid just exceeds the level required for maximum growth.…”

“…A 3 ml syringe with a 23gauge needle was used to remove air and blood clot and the cannula was flushed with the heparinized saline solution. The cannula was sutured behind the bubble on the roof of the mouth, led out from the right nostrum, plugged with a color head pin, and sutured at the dorsal fin (Ok et al, 2001;Bai et al, 2003;Park et al, 2005). Thirty five dorsal aorta cannulated rainbow trout were randomly distributed into seven groups with five fish per group and they were fed one of the seven experimental diets per group by intubation at 1% body weight on dry matter basis.…”

“…Although the effects of dietary protein or amino acid mixtures on PFAAs concentrations in rainbow trout (Murai et al, 1987;Schuhmacher et al, 1997;Vermeirssen et al, 1997) and sea bass, Dicentrarchus labrax (Thebault, 1985) have been reported, the complete dose response relationships for amino acids have not been investigated. In our previous studies, dietary essential amino acids such as arginine, lysine, valine, and threonine requirements for rainbow trout were obtained by using the surgically modified methods in our laboratory (Ok et al, 2001;Ok, 2002;Bai et al, 2003;Park et al, 2005). As a part of our studies on essential amino acid requirements of rainbow trout, the purpose of the present study was to estimate the dietary methionine requirement based on the plasma free methionine and ammonia concentrations in dorsal aorta cannulated rainbow trout.…”