A feeding trial was conducted in a recirculating water system to investigatethe effects of dietary protein levels on growth, feed utilization, hepatosomatic index and liverlipid deposition of juvenile red snapper, Lut...A feeding trial was conducted in a recirculating water system to investigatethe effects of dietary protein levels on growth, feed utilization, hepatosomatic index and liverlipid deposition of juvenile red snapper, Lutjanus argentimaculatus (average initial wet weight 8.0± 0.39 g and total length 3.14 ± 0.3 cm). In the experiment, six fishmeal-based diets wereformulated to contain various protein levels (20% to 45% in 5% increments), with dietary energyranging from 2210.7kJ100g to 2250.2 kJ 100g dry matter. The protein to energy ratios of diets rangedfrom 8.58 mg protein kJ^(-1) to 20.03 mg protein kJ^(-1). Diets were fed for 90 d to triplicategroups of fish stocked in 0.128 m^3 seawater tanks, 25 individuals each. The daily ration of 2% wetbody weight was offered to the fish thrice a day. The fish at the end of the study had more thanten-fold (77.0 g) increase in weight compared to the initial (8.0 g). Fish fed diets of 40% and 45%protein produced significantly (P【0.05) higher weight gain of 77.2 g and 76.5 g, and specific growthrate (SGR) of 2.65% and 2.62% than those of 67.0 g and 68.3 g, and 2.49% and 2.51% of the otherdiets. The broken-line regression of SGR against dietary protein level yielded an optimum dietaryprotein requirement of 42.6% (Y = - 1.6295 + 0.1114 X^2, P【0.05). Survival remained 100% amonggroups. Feed conversion ratio decreased from 0.45 for fish fed 20% dietary protein to 0.35 for fishfed 45% dietary protein. Nitrogen intake increased with an increase in dietary protein, which inturn resulted in an increase in nitrogen gain of fish whole body. Fish fed 40% and 45% protein dietsshowed higher (P【0.05) nitrogen gain (0.27g and 0.26g) than those (0.23g and 025g) fed all otherdiets. Gross energy intake (GEI) in fish fed 45% protein was lower (600.67kJ) than that (607.97 kJ)of 40% protein diet, though the differences were not statistically significant (P】0.05); GEI rangingfrom 677.31 kJ to 663.20 kJ at remaining four diets (20% to 35% protein) did not appear to differsignificantly (P】0.05). The highest energy gain of 518.33 kJ was obtained with fish fed 40% protein,resulting in the highest energy retention efficiency of 85.26%. The hepatosomatic index of fish feddiets of 20%, 25%, 30% and 35% protein were significantly (P【0.05) higher (2.09% to 2.57%) thanthose (1.44% and 1.41%) of fish fed diets containing 40% and 45% protein. Liver lipid contentsdecreased from 8.72% to 7.0% in fish fed dietary protein of 20% to 45% in 5% increments. Resultssuggest that the diet containing 40% to 42.6% protein with a P/E ratio of 17.6 mg protein kJ^(-1) isrequired for good growth of L. argentimaculatus weighing between 8.0 g and 85.2 g under the cultureconditions of the present study.展开更多
Substitution of silkworm pupae （Bombyx mori） for fish meal in broodstock diets for snakeskin gourami （Trichogaster pectoralis） was conducted in order to evaluate the effect of silkworm pupae on feed digestibility ...Substitution of silkworm pupae （Bombyx mori） for fish meal in broodstock diets for snakeskin gourami （Trichogaster pectoralis） was conducted in order to evaluate the effect of silkworm pupae on feed digestibility and broodstock performance. Snakeskin gourami broodfish were fed with isocaloric diets （DE 3,000 a： 50 Kcal/kg） contained 32% crude protein. The levels of substitution were 0%, 50%, 75% and 100% of protein from fish meal （equal to 0%, 14.57%, 21.75% and 29.03% silk worm by weight）. The study was assigned in CRD with 4 treatments and 3 replications. Six hundred of snakeskin gourami with five-month old and average weight of 78.67 ± 2.15 g in female and average weight of 73.00 ± 2.49 g in male were stocked in 12 cages. Fifty fishes of 25 females and 25 males were reared in each cage and fed experimental diet for five months. The result indicated that protein digestibility of test diets were significantly decrease （P 〈 0.05） according to the level of silkworm pupae in diets where as the dry matter digestibility showed no significantly different （P 〉 0.05）. The growth performance and egg fecundity were significantly decreased （P 〈 0.05） according to the levels of silkworm pupae. In contrast, egg quality in term of fry number on first spawned, fingering number on first spawned were not significantly different （P 〉 0.05）. The survival rate of one month nursing fish on first spawned were significantly different （P 〈 0.05）. Hence, silkworm pupae could substitution for 50% of protein from fish meal （14.57% by weight） in snakeskin gourami broodstock diets without any adverse effect on egg quality.展开更多
文摘A feeding trial was conducted in a recirculating water system to investigatethe effects of dietary protein levels on growth, feed utilization, hepatosomatic index and liverlipid deposition of juvenile red snapper, Lutjanus argentimaculatus (average initial wet weight 8.0± 0.39 g and total length 3.14 ± 0.3 cm). In the experiment, six fishmeal-based diets wereformulated to contain various protein levels (20% to 45% in 5% increments), with dietary energyranging from 2210.7kJ100g to 2250.2 kJ 100g dry matter. The protein to energy ratios of diets rangedfrom 8.58 mg protein kJ^(-1) to 20.03 mg protein kJ^(-1). Diets were fed for 90 d to triplicategroups of fish stocked in 0.128 m^3 seawater tanks, 25 individuals each. The daily ration of 2% wetbody weight was offered to the fish thrice a day. The fish at the end of the study had more thanten-fold (77.0 g) increase in weight compared to the initial (8.0 g). Fish fed diets of 40% and 45%protein produced significantly (P【0.05) higher weight gain of 77.2 g and 76.5 g, and specific growthrate (SGR) of 2.65% and 2.62% than those of 67.0 g and 68.3 g, and 2.49% and 2.51% of the otherdiets. The broken-line regression of SGR against dietary protein level yielded an optimum dietaryprotein requirement of 42.6% (Y = - 1.6295 + 0.1114 X^2, P【0.05). Survival remained 100% amonggroups. Feed conversion ratio decreased from 0.45 for fish fed 20% dietary protein to 0.35 for fishfed 45% dietary protein. Nitrogen intake increased with an increase in dietary protein, which inturn resulted in an increase in nitrogen gain of fish whole body. Fish fed 40% and 45% protein dietsshowed higher (P【0.05) nitrogen gain (0.27g and 0.26g) than those (0.23g and 025g) fed all otherdiets. Gross energy intake (GEI) in fish fed 45% protein was lower (600.67kJ) than that (607.97 kJ)of 40% protein diet, though the differences were not statistically significant (P】0.05); GEI rangingfrom 677.31 kJ to 663.20 kJ at remaining four diets (20% to 35% protein) did not appear to differsignificantly (P】0.05). The highest energy gain of 518.33 kJ was obtained with fish fed 40% protein,resulting in the highest energy retention efficiency of 85.26%. The hepatosomatic index of fish feddiets of 20%, 25%, 30% and 35% protein were significantly (P【0.05) higher (2.09% to 2.57%) thanthose (1.44% and 1.41%) of fish fed diets containing 40% and 45% protein. Liver lipid contentsdecreased from 8.72% to 7.0% in fish fed dietary protein of 20% to 45% in 5% increments. Resultssuggest that the diet containing 40% to 42.6% protein with a P/E ratio of 17.6 mg protein kJ^(-1) isrequired for good growth of L. argentimaculatus weighing between 8.0 g and 85.2 g under the cultureconditions of the present study.
文摘Substitution of silkworm pupae （Bombyx mori） for fish meal in broodstock diets for snakeskin gourami （Trichogaster pectoralis） was conducted in order to evaluate the effect of silkworm pupae on feed digestibility and broodstock performance. Snakeskin gourami broodfish were fed with isocaloric diets （DE 3,000 a： 50 Kcal/kg） contained 32% crude protein. The levels of substitution were 0%, 50%, 75% and 100% of protein from fish meal （equal to 0%, 14.57%, 21.75% and 29.03% silk worm by weight）. The study was assigned in CRD with 4 treatments and 3 replications. Six hundred of snakeskin gourami with five-month old and average weight of 78.67 ± 2.15 g in female and average weight of 73.00 ± 2.49 g in male were stocked in 12 cages. Fifty fishes of 25 females and 25 males were reared in each cage and fed experimental diet for five months. The result indicated that protein digestibility of test diets were significantly decrease （P 〈 0.05） according to the level of silkworm pupae in diets where as the dry matter digestibility showed no significantly different （P 〉 0.05）. The growth performance and egg fecundity were significantly decreased （P 〈 0.05） according to the levels of silkworm pupae. In contrast, egg quality in term of fry number on first spawned, fingering number on first spawned were not significantly different （P 〉 0.05）. The survival rate of one month nursing fish on first spawned were significantly different （P 〈 0.05）. Hence, silkworm pupae could substitution for 50% of protein from fish meal （14.57% by weight） in snakeskin gourami broodstock diets without any adverse effect on egg quality.
