The present study was conducted to evaluate the effect of either individual or combined wheat bran(WB) replacement with Azolla pinnata supplemented with Digestin^(TM) in the diet of freshwater prawn, Macrobrachium ros...The present study was conducted to evaluate the effect of either individual or combined wheat bran(WB) replacement with Azolla pinnata supplemented with Digestin^(TM) in the diet of freshwater prawn, Macrobrachium rosenbergii Postlarvae(PL) on growth performance, nutrient utilization, chemical body composition and survival(%). Experimental diets were a wheat bran-soybean based diet with no Azolla and Digestin^(TM)(control, T_1), and diets containing 17% Azolla supplemented with Digestin^(TM) 0%(T_2), 1%(T_3), 2%(T_4) and 3%(T 5). Each experimental diet was allocated into three tanks(6 m^3/tank) fed for 12 wks. Each tank was subdivided into three equal pens by nets(2 m^3) and stoked with 84 PL/m^2. The experimental diets were readily consumed by prawns PLs where both high growth and good feed efficiency were achieved for all diets. The results showed that the diets containing A. pinnata supplemented with Digestin? at the level up to 3% have the higher growth and better nutrient utilization than the control diet. No differences were observed for moisture and protein content among the experimental diets. However, the highest protein content was observed on prawns fed on diets T_1 and T 5 respectively, while the lowest value was recorded for T_4 diet. The results also show that prawn PLs fed the diets contain A. pinnata and supplemented with Digestin^(TM) recorded the highest values of body lipid content compared to the control diet. Feed efficiency and economic conversion rate(ECR) values show that economic performance and the cost-effectiveness of the A. pinnata supplemented with up to 3% Digestin^(TM) recorded the highest net return, and therefore it is recommended for prawn, M. rosenbergii PL's. These results are clearly indicating that A. pinnata have a good potential for use in prawn diets at reasonable levels than other conventional diets.展开更多
An inter-laboratory comparison of the AOAC mouse bioassay for paralytic shellfish poisoning (PSP) toxicity in shellfish was carried out among 25 Chinese laboratories to examine the overall performance for PSP testing ...An inter-laboratory comparison of the AOAC mouse bioassay for paralytic shellfish poisoning (PSP) toxicity in shellfish was carried out among 25 Chinese laboratories to examine the overall performance for PSP testing in China, and to analyze the main factors affecting the performance of this method. The toxic scallop Patinopecten yessoensis collected from coast of Bohai Sea, China, was used as a test sample in the comparison study. The results were reported and evaluated using robust statistical methods. The z scores showed that 80%, 8%, and 12% of laboratories reported satisfactory results, unsatisfactory results, and questionable results, respectively. This evaluation demonstrates that the PSP mouse bioassay is an appropriate method for screening and testing PSP toxicity in shellfish. However, it was found that the experience and skill of technicians, as well as the body weight and health status of mice being used significantly affected the accuracy of the method.展开更多
文摘The present study was conducted to evaluate the effect of either individual or combined wheat bran(WB) replacement with Azolla pinnata supplemented with Digestin^(TM) in the diet of freshwater prawn, Macrobrachium rosenbergii Postlarvae(PL) on growth performance, nutrient utilization, chemical body composition and survival(%). Experimental diets were a wheat bran-soybean based diet with no Azolla and Digestin^(TM)(control, T_1), and diets containing 17% Azolla supplemented with Digestin^(TM) 0%(T_2), 1%(T_3), 2%(T_4) and 3%(T 5). Each experimental diet was allocated into three tanks(6 m^3/tank) fed for 12 wks. Each tank was subdivided into three equal pens by nets(2 m^3) and stoked with 84 PL/m^2. The experimental diets were readily consumed by prawns PLs where both high growth and good feed efficiency were achieved for all diets. The results showed that the diets containing A. pinnata supplemented with Digestin? at the level up to 3% have the higher growth and better nutrient utilization than the control diet. No differences were observed for moisture and protein content among the experimental diets. However, the highest protein content was observed on prawns fed on diets T_1 and T 5 respectively, while the lowest value was recorded for T_4 diet. The results also show that prawn PLs fed the diets contain A. pinnata and supplemented with Digestin^(TM) recorded the highest values of body lipid content compared to the control diet. Feed efficiency and economic conversion rate(ECR) values show that economic performance and the cost-effectiveness of the A. pinnata supplemented with up to 3% Digestin^(TM) recorded the highest net return, and therefore it is recommended for prawn, M. rosenbergii PL's. These results are clearly indicating that A. pinnata have a good potential for use in prawn diets at reasonable levels than other conventional diets.
基金Supported by a thesis research project of General Administration of Quality Supervision, Inspection and Quarantine of China (No. 2010IK168)
文摘An inter-laboratory comparison of the AOAC mouse bioassay for paralytic shellfish poisoning (PSP) toxicity in shellfish was carried out among 25 Chinese laboratories to examine the overall performance for PSP testing in China, and to analyze the main factors affecting the performance of this method. The toxic scallop Patinopecten yessoensis collected from coast of Bohai Sea, China, was used as a test sample in the comparison study. The results were reported and evaluated using robust statistical methods. The z scores showed that 80%, 8%, and 12% of laboratories reported satisfactory results, unsatisfactory results, and questionable results, respectively. This evaluation demonstrates that the PSP mouse bioassay is an appropriate method for screening and testing PSP toxicity in shellfish. However, it was found that the experience and skill of technicians, as well as the body weight and health status of mice being used significantly affected the accuracy of the method.
