Rotifer Nutrition Enhanced Culture Technology And Its Application In Breeding Of Litopenaeus Vannamei Larvae

Rotifers are a kind of important live food, it can improve the survival rate of fish, shrimp, crab seedling stage. But the rotifer culture technique is not perfect, the density is not stable, production demand. And the use of traditional yeast culture of rotifer lack of unsaturated fatty acid, especially EPA, DHA which was extremely important for larval growth and development; strengthening the cultivation of rotifer can improve their nutritional composition and further improve the survival rate of seedling. The study was conducted to investigate the effects of five proportions of bait on the growth performance of Brachionus plicatilis and the water quality of the culture system; the effects of four proportions of nutrient enrichment baiton on the growth performance, fatty acids composition of Brachionus plicatilis and the water quality of the culture system; the effects of four nutrient enrichment Brachionus plicatilis on the growth performance, body composition fatty acids composition of larve of the Penaeus vannamei and the water quality of the culture system. The contents and results of the study are as folllows:1?The effect of five proportions of bait on the growth performance, water quality of culture system in Brachionus plicatilis. This study evaluated the effect of five diets(frozen and concentrated Nannochloropsis sp and yeast at ratios of T1 = 0:1, T2 = 1:0, T3 = 1:1, T4 = 1:2, T5 = 1:3) on rotifer Brachionus plicatilis during an 8-day trial. Results showed that the density of rotifers under the T2 diet was lower than that under the other diet treatments(P <0.05); density under the T1 and T5 diets rapidly increased and was lower than that under the other diet treatments in 1to 4days(P <0.05), and then declined in 4 to 8 days. Rotifer density under the T3 and T4 diets exhibited sustainable growth and was greater than that under other diet treatments, and rotifer density under the T4 diets was greater than that under T3 treatment over the whole experiment. The egg ratio of rotefers under all diet treatments changed continuously during the study. In 2 to 5 days, the reproduction rate of T2 diets was declined, the reproduction rate of T1 and T3 and T4 and T5 diets were rised; the reproduction rate of T1 and T3 and T4 and T5 diets was significantly higher than T2 diets(P <0.05). In 5 to 8 days, the trend of reproduction rate of all diets was smooth. Values of PH, dissolved oxygen, ammonia nitrogen and nitrite of all diets showed increasing trends. With the exception the ammonia nitrogen of T2 diets showed gradually declined trends in 1 to 8 days, and the exception the ammonia nitrogen of T2 diets was significantly lower than other diets(P <0.05). The results show that use T1 and T5 diets which have a high proportion of baker's yeast grow better in 1 to 4 days, and use T4 diets grow better in 4 to 8 days.2?The effect of four proportions of nutrient enrichment baiton on the growth performance, fatty acids, water quality of culture system in Brachionus plicatilis. The experiment evaluated using T1(T1 was baker's yeast contrast), and T2, T3, T4 enhancer diets(T2 was Nannochloropsis sp, T3 was Crack pot of algae powder, T4 was DHA Preotein Seleco) strengthening cultivation of rotifers 12 hours. The results showed that the survival rate of T1 and T2 diets were significantly higher than T3 and T4 diets(P <0.05). The egg ratios, ammonia nitrogen and nitrite under T1 diet was significantly higher than T2, T3 and T4diets(P <0.05). The ammonia nitrogen under T2 and T3 diet was significantly higher than T4diets(P <0.05). The content of DHA of T1, T2, T3 and T4 diets was higher than T0 diets. The content of PUFA?HUFA??-3HUFA?DHA/EPA of T3 and T4 diets was higher than T0 diets. The content of ARA?EPA of T2 diets was significantly higher than T1,T3 and T4 diets( P <0.05). The content of DHA??-3HUFA of T3 and T4 diets was significantly higher than T1 and T2 diets(P <0.05). The results show that the content of DHA of T1, T2, T3 and T4 diets was higher than T0 diets. The content of ARA?EPA of T2 diets was higher than other diets. The content of ARA?EPA of T2 diets was higher than other diets. The content of ARA?EPA of T2 diets was higher than other diets. The content of PUFA?HUFA??-3HUFA?DHA/EPA of T3 and T4 diets was higher than other diets.3?The effect of four nutrient enrichment Brachionus plicatilis on the growth performance, fatty acids, water quality of culture system in Penaeus vannamei. The experiment evaluated the effect of that use T1(T1 was rotifer of baker's yeast contrast), and T2, T3, T4 enhancer diets(T2 was rotifer of Nannochloropsis sp, T3 was rotifer of Crack pot of algae powder, T4 was rotifer of DHA Preotein Seleco) cultivation of larve of Penaeus vannamei 6 days. The results showed that the larve of Penaeus vannamei survival rate under all diets decreased continuously in 1 to 6 days, the larve survival rate under T2 diet significantly higher than other diets in 2 to 6days(P <0.05). On the sixth day, the larve survival rate under T2 diet significantly higher than other diets in 2 to 6days(P <0.05), the larve of Penaeus vannamei survival rate under T3 and T4 diet were higher than the larve of Penaeus vannamei survival rate under T1 diet but not significantly(P >0.05). The larvae abnormal rate of Z3 and M2 period of T3 and T4 higher than T1 and T2 diets. The dissolved oxygen, ammonia nitrogen and nitrite of all diet presents the increasing trend. The content of EPA of T2 diets was significantly higher than other diets(P <0.05). The content of PUFA, HUFA of T3 and T4 diets was higher than T1 and T2 diets but not significantly(P <0.05). The content of DHA??-3 HUFA?DHA/EPA of T3 and T4 diets was significantly higher than T1 and T2 diets(P <0.05). The results showed that the larve of Penaeus vannamei use T2, T3 and T4 enhancer diets cultivation of 6 days can improve the survival rate and abnormal rate of larve; use T2 diets cultivation of larve can significantly improve the survival rate of larve(P <0.05). Use T2 diets cultivation of larve of Penaeus vannamei 6 days can improve the content of EPA of larve, and use T3 and T4 diets cultivation of larve can improve the DHA??-3 HUFA?DHA/EPA of larve(P <0.05).