The Ile Carp Growth And Carp Amino Acid Transporter Law

In order to probe into the effect of free isoleucine added in diet on the growth of crucian carp and the characters of the absorption and transportation of the crucian carp intestine, two experiments were designed, expecting that they could rendered theoretical foundations for practical production and application of aquatic animal feed. In experiment one, two different ingredient feeds were confected. One was composed mainly by rapeseed meal and cotton meal (conventional feed, briefly) and the other was consisted chiefly by blood meal and peanut meal (typical feed). L-isoleucine was supplemented according with the essential amino acid pattern of the fish muscle, or doubled over it. The comparison was set on the feed lacking isoleucine, the first limiting amino acid. The roles of isoleucine added in the different type of feeds were discussed. A perfusing instrument for gut in vitro was introduced in experiment two. The fish intestine was perfused constantly by amino acid solutions containing the relevant isotopes, L-[4, 5-3H]leucine and DL-[4-3H]tyrosine. The characters and principles of the intestine transporting amino acids were groped after. The results extracted from the experiments list as follows:1.The isoleucine added in the conventional feed had no effect on the growth of crucian carp while it added in the typical feed engendered the role of accelerating growth.2.The isoleucine according with the pattern of the fish muscle or doubled the pattern in the conventional feed didn't raise the feed coefficient and protein efficiency ratio. But it raised the utilization of the typical feed in despite of proper or excessive supply.3.The content of the total free amino acids in the fish serum rised with the increase of the added isoleucine. The isoleucine added in the feeds stimulated the absorption of the feed amino acids but there were some differences of the functions in the two feeds.4.The excreting rate of ammonia nitrogen was enhanced after adding the isoleucine consistent with the fish essential amino acid pattern. The catabolic action of protein rised and anabolism of protein booted up simultaneously. The anabolism predominated over the catabolism in the typical feed but it didn't in the conventional feed. At the same time, the reaction were weak when the isoleucine was added excessively.5.The leucine and tyrosine transported by the fish intestine at various concentrations accumulated gradually with time. The concentrational climax of transporting leucine was 8mmol.L-1 but the inhibiting effect occurred at this concentration. It was normal for absorbing and transporting amino acids at other concentrations. It was faint that the amount of transportation was correlated with concentrations. There wasn't any inhibiting reaction to absorb saturated(4.48mmol.L-1) tyrosine by the fish intestine. The transmural fluxes of the lower two concentrations(2mmol. L-1 and 1mmol .L-1) of tyrosine were very low and had no difference all along. The transportation of leucine was higher than that of tyrosine at the same concentrations. The efficiency of transporting leucine was higher by crucian carp than that by grass carp.