Study On The Compensatory Growth Mechanism Of Elopichthys Bambusa Juveniles Under Starvation

(1)The experiment shows that the starvation have certain influence on Growth, body composition, and digestive enzyme activity of Elopichthys bambusa juveniles.Effect of starvation on the juveniles'growth is apparent. Within 15 days, weight loses over the starvation. On the 7th day significant difference (P<0.05) is revealed, with weight loss rate as 12.32%. On the 15th days, weight loss rate becomes 18.36%. which shows starvation greatly influences on weight. In therms of body composition, when starved to the 15th day, the juveniles have more of water, compared to the preliminary starvation period (P<0.05). Protein decreases, different than that of the very beginning (P<0.05). Fat increases and then decreases, higher than that of the 7th day (P<0.05), and lower hugely than that of the 15th day. Ash content diminishes somewhat during the starvation. Regarding glycogen, liver glycogen changes more than the muscle glycogen. Liver glycogen on the 7th day loses greatly (P<0.05), but rebounds a little bit on the 15th day. Although muscle doesn't change much, it on the whole decrease continuously. The above findings indicate that in a rather short starvation period starvation is reduced by consuming glycogen (especially the liver glycogen) and protein while fat accumulates some. At some point, fat as the energy source begin to consume while the liver glycogen starts to go up. At the same time, intestinal digestive enzyme adjusts too.(2) The experiment shows that the compensatory growth have certain influence on Growth, body composition, serum biochemical index and digestive enzyme activity.Seen from the final weights, there are big differences between the control group and the treatment groups (P<0.05), and differences among the treatment groups are not apparent, which shows that weight gain of feeding after starvation is lower than that of continuous feeding. That's to say, during the experiment juveniles acquire partial CG. As the fasting of each treatment group extends, weight gain rate increases, showing a tendency to approach the control group. It may be analyzed that the CG period needs to be stimulated by certain fasting time. Each group over the experiment shows little difference in survival rate. Fat rate of each group varies little and gradually decreases as the fasting time extends in each treatment period, which indicates that feeding-after-starvation influences little on fat rate (P<0.05). Control group A has the highest relative weight gain; other groups fed after starvation also has a higher weight gain rate, approaching Group A. Feeding rate of each treatment group is higher than the control group (P<0.05), which shows during the CG period, starved juveniles have a significant feeding rate. Control group differ little in food conversion efficiency from treatment B and C, but greatly from treatment D and E, which shows that extending starvation time can improve food conversion efficiency.During the CG period, regarding body composition, each group differs little in water and protein (P<0.05). Crude fat after starved one day is higher that the control group (P<0.05), and begin to decrease after extending the starvation time. Ash content decreases as the starvation time extends, and ash content of each group is lower than the control group (P<0.05),but among themselves differs little. Therefore, CG period has certain influence on fat and ash content.As for serum biochemical indexes, control group A differs in Lysozyme activity from treatment group E, but differs greatly from the rest group, which indicates there is little difference between the group starved 8 days and fed 16 days and the control group in non-specific immunity; while GSH and MDA show a tendency of going up first and then down. There is huge difference between the control group having the highest T-AOC and other treatment groups (P<0.05), and trending downward as the fasting time extends, which shows feeding-after-starvation decreases oxidation resistance.Influences on intestinal digestive enzyme:the continuously fed group differs little in front intestinal digestive enzyme activity from the group fed after being starved 1 day, but greatly from other treatment groups (P<0.05); middle intestinal digestive enzyme activity, on the first or the second starvation day, show apparent difference from the control group, but on the 4th day rebounds to the level of the control group, and continues to fall on the eighth day; feeding-after-starvation's influence on back intestinal digestive enzyme activity:the continuously fed group differs great from the group D and E(P<0.05), trending upward as the starvation time extends.The experiment shows different CG treatments have certain influence on Elopichthys bambusa juveniles'growth, body composition, serum biochemical indexes, and intestinal digestive enzyme activity.