Prelimimary Studies On The Relationships Between Growth Performance And Blood Biochemical Indices Of Tilapia Oreochromis Aureus

Three feeding categories were devised to feed tilapia (Oreochromis aureus): fresh earthworm, starvation for 3 weeks and re-feeding, formulated feed. The fresh earthworm group was fed with ice earthworm, and the earthworm contained rich nutrition gradients and active materials, the tilapia were expected to grow fast and well. The tilapia in compensatory group were starving for three weeks then fed with formulated feed for two weeks, and were used to study the change of blood biochemical indices during the period of starving and re-feeding. The formulated group was control group, and the tilapia were fed formulated feed bought from Qingdao aquaculture feed company.The tilapia were about 12 cm long, and about 90 g weight, and were divided to three feeding group, each group was triplicate, 18 tilapia each were raised in a tank, and its cubage was 200 L. The tilapia were raised in fresh water, and the temperature of water was 25±2℃, pH value was 8.0±0.5, three meals a day, 08:00, 14:00, 19:00, cleaned the leftover feed 1h after feeding, and exchange the 1/3 tank water. The experiment had investigated the changes of blood biochemical indices under different feed categories. Studies were carried out on the relationships between growth performance and blood indices, trying to find out which induces can exactly reflect growth performance.The result showed that; The tilapia acquired a compensatory growth, when the tilapia were during the period of compensatory growth, the weight gain ratio and specific growth rate was significantly higher than that in formulated group (p<0.05), and higher than that in fresh earthworm group, but not significantly. The fresh earthworm group and formulated group was significantly higher than that of compensatory group in total weight gain and specific growth rate (p<0.05). The fresh earthworm group was higher than that of the formulated group in total weight gain and specific growth rate, but not significantly. Glucose, triacylglyerol, the red blood cell count and hemoglobin dropped significantly after starving for one week, but then was stable in the following starving weeks; Total serum protein concentration did not drop significantly. When re-feeding for one week, the biochemical indices went up obviously.The serum total protein concentration,cholesterol and T4 was significantly correlated to the growth performance (p<0.01), the correlation coefficient was 0.872,0.803 and 0.876, separately; The correlated coefficient of hemoglobin was 0.615, and was significantly correlated to the growth performance (p<0.05); the red blood cell count, white blood cell count and AKP was high correlated to the growth performance, the correlation coefficient was 0.580,0.551 and 0.557, separately. Triacyglycerol and phosphorus was correlated to the growth performance, and the correlated coefficient was 0.366 and 0.231.The serum calcium was minus correlated to the growth performance, and the correlated coefficient was -0.121. From the study, the authors suggested the serum total protein, cholesterol, and hemoglobin be the new indices which could reflect growth performance.According to the sequence, we designed primers, and we cloned the part of the IGF-Ⅰgene sequence at the following conditions: denature temperature at 95℃,3 min; annealing temperature at 72℃,5 min, and 36 cycles from the Pacific fluke, Japanese sea bass, slickhead, and confirmed that IGF-Ⅰgene was in this three kinds of fish.Using Methioninum and Zinc sulfate heptahydrate as reagent, they were mixed together at pH 5.5,80℃for 1 h, and their ratio was 2:1, finally we got the production Methionine chelate Zinc.The Methionine chelate Zinc is white, flouder, and it is hard to be dissolved in water at room temperate, and can not be dissolved in ethanol, it was detected by atomic absorption spectrometry, the Zinc was 15% percent, and its chlate ratio is 88.2%.