An 8-week feeding trial was conducted to assess the effect of soybean meal （SBM）, groundnut meal （GNM） and blood meal （BM） addition in diets with or without （1%） fishmeal on the performance, N-digestibility an...An 8-week feeding trial was conducted to assess the effect of soybean meal （SBM）, groundnut meal （GNM） and blood meal （BM） addition in diets with or without （1%） fishmeal on the performance, N-digestibility and cost of production of growing grasscutters. Fifty-four grasscutters （9-week-old） of mixed sexes were randomly assigned to six dietary treatments, using a completely randomized design （CRD） in a 2 × 3 factorial arrangement, with three grasscutters per treatment and three replicates each. Treatments 1-3 （TI-T3） contained no fishmeal, whilst treatments 4-6 （T4-T6） had 1% fishmeal added. The diets were formulated to be isocaloric and isonitrogenous. N-digestibility was significantly high for SBM diets with or without fishmeal, 83.91% and 82.19%, respectively, followed by BM diets. Average daily gain （ADG） was significantly （P 〈 0.05） high （12.95 g） for BM diet without fishmeal. Feed cost per kg diet was the lowest （US$0.195） for the same BM diet. The results indicated that the inclusion of SBM and BM in the diet of grasscutters with or without 1% fishmeal could improve performance and it may be the most economical for feeding BM in the diet without fishmeal.展开更多
The effect of two diets containing fish acid silage were studied, the first one offered as dry diet and the second one as a wet diet, in final culture cycle of PactS. Previous experiences showed that diets without fis...The effect of two diets containing fish acid silage were studied, the first one offered as dry diet and the second one as a wet diet, in final culture cycle of PactS. Previous experiences showed that diets without fishmeal maintain same growth rate in semi intensive system, compared to diets containing 8% and 20% fish meal. Feeding trials were carried out in CENADAC （27°32′ S, 58030＇ W） in a semi intensive pond culture system for 122 days. Two experimental feed including fish silage, a liquid product obtained of fish residues treated by enzymes action, were formulated. Fish silage was prepared by mincing and blending fish viscera with sufficient formic acid （2.11% v/w） to attain a stable pH of 3.5. Fish were daily fed initially with the dry ration at 1.3% bw/d and at a rate of 0.55 g of protein/100 g of fish with the wet ration. At the end of the experience the average weight observed for dry fed fish was 1,513.5 g and 1,560.3 g for those wet fed. The daily growth was 3.69 g/d for the first group and 3.9 g/d for the second one. The final FCR was 2.72 and 3.01 for each group without significant differences. These results showed that it is possible to grow out paco with wet self made feed without fish meal and with similar growth that those fed dry diet.展开更多
The homologous genes FLORICAULA (FLO) in Antirrhinum and LEAFY (LFY) in Arabidopsis are known to regu- late the initiation of flowering in these two distantly related plant species. These genes are necessary also for ...The homologous genes FLORICAULA (FLO) in Antirrhinum and LEAFY (LFY) in Arabidopsis are known to regu- late the initiation of flowering in these two distantly related plant species. These genes are necessary also for the expression of downstream genes that control floral organ identity. We used Arabidopsis LFY cDNA as a probe to clone and sequence a papaya ortholog of LFY, PFL. It encodes a protein that shares 61% identity with the Arabidopsis LFY gene and 71% identity with the LFY homologs of the two woody tree species: California sycamore (Platanus racemosa) and black cottonwood (Populus trichocarpa). Despite the high sequence similarity within two conserved regions, the N-terminal proline-rich motif in papaya PFL differs from other members in the family. This difference may not affect the gene function of papaya PFL, since an equally divergent but a functional LFY ortholog NEEDLY of Pinus radiata has been reported. Genomic and BAC Southern analyses indicated that there is only one copy of PFL in the papaya genome. In situ hybridization experiments demonstrated that PFL is expressed at a relatively low level in leaf primordia, but it is expressed at a high level in the floral meristem. Quantitative PCR analyses revealed that PFL was expressed in flower buds of all three sex types - male, female, and hermaphrodite with marginal difference between hermaphrodite and unisexual flowers. These data suggest that PFL may play a similar role as LFY in flower development and has limited effect on sex differentiation in papaya.展开更多
The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method t...The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method that could detect MG and LMG simultaneously, and then investigated the persistence of these two toxins in the tissues of juvenile perch (Lateolabrax japonicus) post sub-chronic MG exposure at 1.0 mg/L. Exposure lasted for 2 h everyday and was repeated six times. The perch were then placed in MG-free seawater for 100 d to eliminate the toxins. Results show that MG accumulated in the tissues, including the gills, liver, muscle, blood and viscera, and then was metabolized rapidly to LMG. The concentrations of these two toxins increased significantly with the accumulation process. In general, the highest concentrations of MG and LMG in all tissue exceeded 1 000 μg/kg, except for MG in the muscle. The order of accumulation levels (highest to lowest) of MG was gill>blood>liver>viscera>muscle, while that of LMG was liver>blood>gill>viscera>muscle. High levels of MG or LMG could persist for several hours but decreased rapidly during the elimination process. The concentration of LMG was much higher than that of MG during the experiment, especially in the gill, liver and blood. Therefore, the three tissues play important roles in toxin accumulation, biotransformation, and elimination. Although the MG and LMG concentrations in muscle were much lower than in other tissues, the content still exceeded the European minimum required performance limit (MRPL), even after 2 400 h (100 d) of elimination. This demonstrates that it is extremely difficult to eliminate MG and LMG from tissues of perch, and therefore use of these toxins is of concern to public health.展开更多
文摘An 8-week feeding trial was conducted to assess the effect of soybean meal （SBM）, groundnut meal （GNM） and blood meal （BM） addition in diets with or without （1%） fishmeal on the performance, N-digestibility and cost of production of growing grasscutters. Fifty-four grasscutters （9-week-old） of mixed sexes were randomly assigned to six dietary treatments, using a completely randomized design （CRD） in a 2 × 3 factorial arrangement, with three grasscutters per treatment and three replicates each. Treatments 1-3 （TI-T3） contained no fishmeal, whilst treatments 4-6 （T4-T6） had 1% fishmeal added. The diets were formulated to be isocaloric and isonitrogenous. N-digestibility was significantly high for SBM diets with or without fishmeal, 83.91% and 82.19%, respectively, followed by BM diets. Average daily gain （ADG） was significantly （P 〈 0.05） high （12.95 g） for BM diet without fishmeal. Feed cost per kg diet was the lowest （US$0.195） for the same BM diet. The results indicated that the inclusion of SBM and BM in the diet of grasscutters with or without 1% fishmeal could improve performance and it may be the most economical for feeding BM in the diet without fishmeal.
文摘The effect of two diets containing fish acid silage were studied, the first one offered as dry diet and the second one as a wet diet, in final culture cycle of PactS. Previous experiences showed that diets without fishmeal maintain same growth rate in semi intensive system, compared to diets containing 8% and 20% fish meal. Feeding trials were carried out in CENADAC （27°32′ S, 58030＇ W） in a semi intensive pond culture system for 122 days. Two experimental feed including fish silage, a liquid product obtained of fish residues treated by enzymes action, were formulated. Fish silage was prepared by mincing and blending fish viscera with sufficient formic acid （2.11% v/w） to attain a stable pH of 3.5. Fish were daily fed initially with the dry ration at 1.3% bw/d and at a rate of 0.55 g of protein/100 g of fish with the wet ration. At the end of the experience the average weight observed for dry fed fish was 1,513.5 g and 1,560.3 g for those wet fed. The daily growth was 3.69 g/d for the first group and 3.9 g/d for the second one. The final FCR was 2.72 and 3.01 for each group without significant differences. These results showed that it is possible to grow out paco with wet self made feed without fish meal and with similar growth that those fed dry diet.
文摘The homologous genes FLORICAULA (FLO) in Antirrhinum and LEAFY (LFY) in Arabidopsis are known to regu- late the initiation of flowering in these two distantly related plant species. These genes are necessary also for the expression of downstream genes that control floral organ identity. We used Arabidopsis LFY cDNA as a probe to clone and sequence a papaya ortholog of LFY, PFL. It encodes a protein that shares 61% identity with the Arabidopsis LFY gene and 71% identity with the LFY homologs of the two woody tree species: California sycamore (Platanus racemosa) and black cottonwood (Populus trichocarpa). Despite the high sequence similarity within two conserved regions, the N-terminal proline-rich motif in papaya PFL differs from other members in the family. This difference may not affect the gene function of papaya PFL, since an equally divergent but a functional LFY ortholog NEEDLY of Pinus radiata has been reported. Genomic and BAC Southern analyses indicated that there is only one copy of PFL in the papaya genome. In situ hybridization experiments demonstrated that PFL is expressed at a relatively low level in leaf primordia, but it is expressed at a high level in the floral meristem. Quantitative PCR analyses revealed that PFL was expressed in flower buds of all three sex types - male, female, and hermaphrodite with marginal difference between hermaphrodite and unisexual flowers. These data suggest that PFL may play a similar role as LFY in flower development and has limited effect on sex differentiation in papaya.
基金Supported by the Special Fund of Chinese Government for Basic Scientific Research Operations in Commonweal Research Institute (Yellow Sea Fisheries Research Institute) (No. 2007-qn-12)the Strategic Research Grant of the Databases and Risk Analysis of POPs in Aquatic Products (No. 2005DIB4J049)the Standard System Research on Quality and Safety of Aquatic Products (No. 2004DEA70880)
文摘The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method that could detect MG and LMG simultaneously, and then investigated the persistence of these two toxins in the tissues of juvenile perch (Lateolabrax japonicus) post sub-chronic MG exposure at 1.0 mg/L. Exposure lasted for 2 h everyday and was repeated six times. The perch were then placed in MG-free seawater for 100 d to eliminate the toxins. Results show that MG accumulated in the tissues, including the gills, liver, muscle, blood and viscera, and then was metabolized rapidly to LMG. The concentrations of these two toxins increased significantly with the accumulation process. In general, the highest concentrations of MG and LMG in all tissue exceeded 1 000 μg/kg, except for MG in the muscle. The order of accumulation levels (highest to lowest) of MG was gill>blood>liver>viscera>muscle, while that of LMG was liver>blood>gill>viscera>muscle. High levels of MG or LMG could persist for several hours but decreased rapidly during the elimination process. The concentration of LMG was much higher than that of MG during the experiment, especially in the gill, liver and blood. Therefore, the three tissues play important roles in toxin accumulation, biotransformation, and elimination. Although the MG and LMG concentrations in muscle were much lower than in other tissues, the content still exceeded the European minimum required performance limit (MRPL), even after 2 400 h (100 d) of elimination. This demonstrates that it is extremely difficult to eliminate MG and LMG from tissues of perch, and therefore use of these toxins is of concern to public health.
