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1.
An experiment was conducted to determine effects of feeding levels on growth performance, feed utilization, nutrient deposition, body composition and apparent digestibility coefficients (ADCs) of nutrients for juvenile Chinese sucker (initial weight, 11.77±0.22 g). Chinese sucker were fed a practical diet from 0% (starvation) to 4.0% (at 0.5% increments) body weight (bw) day?1 for 8 weeks. The results showed that growth performance, feed utilization, nutrient deposition, body composition and ADCs of dry matter, protein and energy were significantly (P<0.05) affected by feeding levels. Survival was the lowest for the starvation group. Final mean body weight, growth rate, thermal‐unit growth coefficient (TGC) increased with feeding rate from 0% to 3.0% bw day?1 (P<0.05) and showed no significant differences above the level (P>0.05). Feed conversion rate was significantly lower at a feeding level of 2.5% bw day?1 than above and below the level (P<0.05). Protein efficiency ratio was markedly highest at the 2.5% bw day?1 ration level (P<0.05). Fish fed at the feeding level (1.0% bw day?1), which represented a maintenance ration (energy gain was less than 2.27 kJ fish?1 day?1), showed positive protein deposition but negative lipid deposition. This indicates that fish fed a maintenance ration mobilize body lipid reserve to support protein deposition. Lipid contents of whole body, muscle and liver increased with increasing feeding rates from 0.5% to 3.0% bw day?1 and showed no significant differences above the level (P>0.05). Protein contents of whole‐body composition increased with feeding rate from 0.5 to 3.0% bw day?1 (P<0.05) and showed no significant differences above the level (P>0.05), whereas muscle and liver remained relatively stable with the different ration amount with the exception of fish fed a ration of 0.5% bw day?1, at which Chinese sucker possessed significantly lower body protein concentration (P<0.05). The ADCs of dry matter, protein and energy decreased with increasing feeding levels from 0.5% to 3.0% bw day?1 and then remained relatively constant over the level. Based on the broken‐line regression analysis using WG data, the optimum and maintenance feeding levels for Chinese sucker were 3.10% bw day?1 and 0.45% bw day?1 respectively.  相似文献   

2.
Abstract

A 3 × 3 factorial experiment was designed to determine the effects of protein levels and feeding rate on growth and body composition of hybrid clariid catfish, Clarias gariepinusX Heterobranchus bidorsalis, over 12 weeks experimental period. Hybrid catfish (initial mean weight 12.53±0.35 g) were stocked in three feeding rates (3%, 5%, or 7% body weight/day (bw/day) and three crude protein levels (30%, 35%, or 40%). Each treatment was assigned randomly to three tanks. Final weight was higher for fish fed at 40% than those fed at 30% and 35% CP. There was no significant difference (P >0.05) in fish fed at 3%, 5%, and 7% bw/day. Also, there was no significant interaction between feeding rate and dietary protein level for weight gain, specific growth rate or feed conversion ratio. Weight gain and feed efficiency under feeding rates increased linearly as protein level increased. Dietary protein levels and feeding rate had significant effect on fish survival. Protein levels had a positive linear effect on fish body protein in all the feeding rates. Based on the above results, 40% CP level and 5% bw/day feeding rate are suggested to be optimal for achieving optimum growth rate and body composition.  相似文献   

3.
An eight-week feeding trial has been conducted to determine the optimum ration for Indian major carp, Labeo rohita, fingerling (4.10 ± 0.30 cm, 0.55 ± 0.16 g) by feeding a purified diet (40% CP; 3.61 kcal g−1 GE) at six levels, 2, 4, 6, 8, 10, and 12% of body weight per day, at 0800 and 1600 h, in triplicate, to 20 fish per trough fitted with a water flow-through system. Highest weight gain, best feed conversion ratio (FCR), best specific growth rate (SGR%), and highest protein efficiency ratio (PER) were evident for rations of 6–8% body weight. Second-degree polynomial regression analysis for FCR, PER, protein, and energy retention data indicated the break-points occurred at 6.55, 6.75, 6.80, and 6.95% bw per day, respectively. Significant (P < 0.05) differences between body composition were observed for fish fed different rations. Maximum body protein content was recorded for 6% and 8% rations. A linear increase in body fat content was evident with increasing ration. Body moisture and ash content remained non-significantly (P > 0.05) low for higher rations, however. On the basis of these results it is recommended that feeding in the range 6.5–7.0% bw per day corresponding to 2.6–2.8 g protein and 23.49–25.31 kcal energy per 100 g of the diet per day is optimum for growth and efficient feed utilization of Labeo rohita. Results for 2–4% rations (0.8–1.6 g protein and 7.23–14.46 kcal energy) suggest these amounts approximate to the maintenance requirement of this fish.  相似文献   

4.
Abstract In an attempt to identify appropriate feeding rates for multispecies of fish raised in fertilized earthen ponds, the present work was conducted over a 19‐week experimental period to establish the growth performance, production and body composition of Nile tilapia, common carp and silver carp fed 0.0%, 0.5%, 1.0%, 3.0%, 5.0% biomass and to apparent satiation (treatments). Twelve ponds were stocked with a similar number and weight of each fish species. Two ponds were assigned to each of the treatments, and a 25% protein pelleted fish feed was used to feed fish at the specified rate of feeding. At the end of the experiment, growth, weight gain, survival, yield and body composition of fish groups were affected by the treatments. The economic effectiveness also varied among treatments. The most conspicuous attribute of the feeding rates was its lack of influence on growth (g day?1), weight gain (g per fish), yield (kg ha?1) or body composition of silver carp. The results of whole‐body proximate analysis indicated that various feeding rates had either an irregular pattern or no effects on the protein and ash gain per 100 g of fish body weight (bw) gain. The most notable exceptions were significant (P < 0.05) increases in body fat and gross energy gains in Nile tilapia, common carp and silver carp accompanied by decreases in percentages of moisture (but not in silver carp) as feeding rate increased. Among the six different feeding levels, feeding to apparent satiation (feed amount was equivalent to 2.67% of fish bw day?1) appeared to be optimal, as it significantly (P < 0.05) supported the highest fish production, income and net profit compared with all other treatments except for the 3% feeding level, for which the differences in those measurements were comparable.  相似文献   

5.
The effects of feeding levels on the growth, survival and feed utilization of hatchery-reared juvenile Babylonia areolata Link 1807 were assessed at four daily rations of 3%, 5%, 10% and 15% of body weight. Three duplicated groups of juveniles (mean initial body weight 0.26 ± 0.3 g) were stocked into indoor rearing tanks supplied with a flowthrough system of ambient natural seawater for 150 days. Growth in body weight differed significantly (P < 0.05) among the various feeding levels. Final body weight of individual snails increased with increased feeding ration at a particular ration level. Meanwhile, increasing the daily ration to 10% and 15% significantly improved growth and feed utilization efficiency. The food conversion ratios (FCRs) for the 3% and 5% feeding levels were significantly lower than those for the other feeding levels. Final survival was best at feeding levels of 10% and 15% of body weight, ranging between 96.9% and 97.3%, but was very poor at the 3% and 5% feeding levels, ranging from only 49.5% to 54.8%.  相似文献   

6.
A 83‐d feeding experiment was undertaken to evaluate the effects of dietary protein and lipid levels on growth and body composition of spotted halibut, Verasper variegatus (initial average weight of 93.0 ± 1.0 g). Nine diets were formulated to contain three protein levels (40, 45, and 50%), each with three lipid levels (8, 12% and 16%). Each diet was randomly fed to triplicate groups of 20 fish per tank in the indoor culture system. Results showed that the survival rate of fish was not significantly affected by protein and lipid levels (P > 0.05). Weight gain, specific growth rate (SGR), and feed intake (FI) significantly decreased with the increasing dietary lipid levels (P < 0.05). Feed efficiency significantly increased while the feed conversion ration significantly decreased with increasing dietary protein levels (P < 0.05). Weight gain, SGR, FI, and feed efficiency of fish fed 50% protein and 8% lipid were significantly higher than that of the other groups. For each level of dietary lipid, the increase in dietary protein resulted in significant increases in whole‐body crude protein (CP) contents (P < 0.05); the increase in dietary lipid caused significant increases in whole‐body crude lipid content and gross energy at each protein level (P < 0.05). The muscle CP, lipid, and gross energy had the same tendency. The results of this study indicated that increasing dietary lipid levels did not result in a protein‐sparing effect. It could be recommended that the proper dietary protein and lipid levels of spotted halibut were 50 and 8%, respectively.  相似文献   

7.
Adult green sea urchins Strongylocentrotus droebachiensis were fed three different quantities (0.25, 0.50, 1.00% body weight/d) of a prepared feed during a 12‐wk experiment to determine the effect of food ration on gonad quantity and quality. A diet of kelp, Laminaria longicruris and/or L. digitata, fed at satiation (3% body weight/d) and urchins taken from the wild at the beginning and end of the experiment served as controls. Urchins fed prepared feed or kelp increased their percent gonad yield significantly over the experimental period. Affer 12 wk, individuals fed the prepared diet at 0.50 or 1.00% body weighffd had significantly higher percent gonad yields (mean ± SEM: 23.5 ± 0.6% and 23.4 ± 0.7%, respectively) than urchins fed at 0.25% body weight/d (18.0 ± 1.0%) or control animals given kelp (18.3 ± 0.8%). There was no significant difference in gonad yield between the 0.50 and 1.00% feeding levels. All feeding treatments had significantly higher percent gonad yields than urchins sampled from the wild at the end of the experiment that had recently spawned (2.8 ± 0.5%). There was no significant difference in gonad taste among urchins fed the prepared diet at 0.25% body weight/d, those given kelp, or those collected from the wild at the end of the experiment (good to very good ratings), but all of these treatments had significantly better tasting gonads than urchins given the prepared feed at 0.50 or 1.00% body weight/d (satisfactory ratings). Gonad taste rating of urchins fed a prepared diet was dependent on ration with greater feed amounts leading to worse tasting gonads (linear regression: r2= 0.68, P < 0.01). Gonad color, texture, and firmness did not differ significantly among any of the feed ration treatments or kelp control. Results suggest that the best ration for prepared feed would be 0.50% body weightld since this would optimize gonad yield while minimizing feed costs. Further research on prepared feeds is required to optimize both gonad color and taste.  相似文献   

8.
The effects of four levels of food supply (0.5%, 1%, 2% and 3% body weight daily) were investigated on some reproductive traits and growth of hybrid tilapia in outdoor concrete tanks. Fast-growing fish matured early in the season (March), but spawning started late in May. Smallest size of males and females at first maturity was 8.1 cm. Fish size at maturity appears to be influenced by the feeding level, which affects the growth of fish. For both sexes, no significant difference was found in gonadosomatic index (GSI) among different treatments. Mean percentage of mature fish decreased with decreasing food supply and was found to be significantly different between fishes fed at 3% (46%) and 0.5% (28%) body weight. Fecundity increased with increased feeding levels, although significant differences were found only between 3% and other feeding rates (0.5–2.0%). The fecundity per g female was higher at the lower ration levels (0.5% and 1%) than at the higher feeding levels. Egg quality, with respect to egg size, hatchability. fry length and weight, was not affected by the feeding rates. Final mean weight and food conversion ratios were significantly influenced by feeding rates. Higher increase in ovary weight with increasing body weight of mature females fed at 0.5% body weight than fishes receiving higher food levels suggests that in these fish, more food resources are diverted towards gonad building than to somatic growth.  相似文献   

9.
为研究池塘工程化循环水养殖模式下投喂频率对大口黑鲈(Micropterussalmoides)生长、生理及肝脏生长激素基因(GH)、类胰岛素生长因子-I基因(IGF-I)相对表达丰度的影响,选用初始体重为(5.0±0.4) g的大口黑鲈为研究对象,设置3个投喂频率组(2次/d、3次/d、4次/d),每组3个重复,开展为期120 d的养殖试验。结果表明,第30天和第60天时,大口黑鲈末体重、增重率和特定生长率均未受到投喂频率的显著影响(P0.05),而在第90天时, 2次/d组试验鱼的生长显著高于4次/d组(P0.05),与3次/d组相比无显著性差异(P0.05);第120天时, 2次/d组试验鱼的生长显著高于3次/d组和4次/d组(P0.05);投喂频率对血清谷氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、碱性磷酸酶(ALP)活性、溶菌酶、皮质醇和甘油三酯(TG)含量、肝脏总抗氧化能力(T-AOC)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量均无显著性影响(P0.05)。随着投喂频率的增加,肝脏过氧化氢酶(CAT)活性及血清总蛋白(TP)、血糖(Glu)含量呈降低的趋势且血清总胆固醇(TC)呈上升的趋势;第30天时投喂频率对肝脏总超氧化物歧化酶(T-SOD)活性无显著性影响,而第60天、第90天和第120天时,4次/d组T-SOD活性显著低于2次/d组(P0.05)。第30天、第60天和第120天时, 2次/d组肝脏IGF-I基因的相对表达量最高(P0.05),第90天时各组间肝脏IGF-I相对表达量无明显差异(P0.05);第30天和第60天时,肝脏GH基因相对表达量未受到投喂频率的影响(P0.05),而第90天和第120天时4次/d组肝脏GH基因相对表达量显著低于2次/d组(P0.05)。因此,基于大口黑鲈的生长性能、生理效应及肝脏GH、IGF-I基因表达丰度的综合考虑,池塘工程化循环水养殖模式下初始体重为(5.0±0.4)g的大口黑鲈适宜投喂频率为2次/d。  相似文献   

10.
The objective of the present study was to evaluate the effect of plant‐ingredient‐based feeds on fillet fatty acid profiles, proximate composition, carcass traits, and sensory characteristics of three Indian major carps (IMCs), Catla catla, Labeo rohita, and Cirrhinus mrigala, when fed at different levels of their body weight. An experimental feed was prepared with only plant ingredients. The IMCs were fed twice daily at 1.0, 1.5, 2.0, and 2.5% of their body weight for 150 d in 0.06‐ha earthen pond polyculture systems. The maximum growth and best feed utilization was achieved with feeding at 2% of fish biomass in the ponds. Fillet yield and lipid recovery increased significantly (P < 0.05), with increasing feeding level up to 2% of body weight and plateaued thereafter. In fillets, eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) concentration increased with increasing feeding levels. Carcass traits, sensory characteristics, and consumer acceptance of IMC fillets were not influenced by feeding plant‐ingredient‐based feeds at different feeding rates.  相似文献   

11.
Abstract

Two trials evaluated winter feeding strategies for small golden shiners, Notemigonus crysoleucas destined for the crappie, Po-moxis spp. market. Fish were stocked at 615 g/pool (approximately 127 or 158 fish/m2, trials 1 and 2, respectively) in aerated, 5.9-m2 pools for 100 and 104 days, respectively. In the first trial, fish were fed a commercially available 32% crude protein crumbled, extruded pellet once daily at feeding rates of 0% (fertilizer only), 1%, or 2% of body weight/day (bw/d) on days when the afternoon air temperature was >7°C. Unfed fish lost weight, and their condition declined. Fish fed at 1% maintained both weight and condition, while fish fed at 2% gained weight. Fish in the second trial were fed once daily at 1% bw/d on those days when the air temperature was either >7°C or >10°C, with either a commercially available crumbled, extruded pellet or a sinking pellet (compressed). Fish fed crumbles were in significantly better condition at harvest than fish fed a sinking pellet, regardless of trigger feeding temperature, although average weight was not significantly different. Feeding on days with air temperatures >7°C provided 13% more feeding days than a trigger temperature >10 °C, and fish grew more over the winter. Two condition indices, relative weight (Wr) and Fulton's condition factor (K), proved useful in evaluating the condition of golden shiners cultured using different feeding strategies.  相似文献   

12.
A 56‐d feeding trial was conducted to evaluate the effects of dietary lysine levels on growth performance, intestinal digestive enzymes, and nonspecific immune response of Apostichopus japonicus juveniles. Five semipurified diets were formulated to contain graded levels of lysine (from 0.28 to 2.32% of dry matter). Although no significant differences (P > 0.05) were observed in survival rate, final weight (FW), and body weight gain (BWG), the FW and BWG increased from 0.28 to 1.19% with increasing dietary lysine levels, then showed a declining tendency. Broken‐line regression analysis of BWG indicated sea cucumber requires lysine at 0.76% of dry diet. Proximate composition, lysine content of the body wall, and total amino acid profiles were not affected by dietary treatments. Intestinal protease level increased with increasing dietary lysine level from 0.28 to 1.19%, then decreased. Acid phosphatase and superoxide dismutase activities of the sea cucumbers were not affected by various dietary lysine levels; however, significantly (P < 0.05) higher alkaline phosphatase activity was observed in sea cucumbers fed 2.32% lysine diet than those fed diets having 0.28 and 1.89% lysine. Overall, sea cucumber juveniles fed with diets containing between 0.76 and 1.19% lysine showed better growth performance, digestive enzymes, and nonspecific immune enzyme activities.  相似文献   

13.
A feeding trial was conducted to study the effect of mannan oligosaccharide (MOS) supplementation on growth, body composition, haematology, biochemical parameters and histology of Asian seabass (Lates calcarifer) fingerlings (8.13 ± 0.06 g average weight). Mannan oligosaccharide was supplemented at five different concentrations viz., 0%, 0.5%, 1%, 1.5% and 2% levels in the diet (40% protein and 9% lipid) of L. calcarifer. The results of the 60 days feeding trial showed that there was a significant (P < 0.05) increase in the final body weight, weight gain (WG), WG%, average daily gain, survival, specific growth rate, daily growth coefficient, hepatosomatic index and viscerosomatic index in the fish fed diet containing 1% MOS. Whole body composition of post‐fed animals showed non‐significant differences (P > 0.05) among the various treatment groups. The analysis of haematological parameters showed that there was no significant (P > 0.05) differences among different treatments but for the haemoglobin content which was significantly (P < 0.05) higher in the fish fed 1% MOS. Biochemical parameters revealed that glucose, urea, cholesterol and triglyceride content showed significant (P < 0.05) difference between control and MOS‐supplemented group. Histological observations of post‐fed animals revealed that MOS supplementation resulted in increased absorptive surface area of the intestine and increased glycogen deposition in liver. The result of this experiment infers that MOS supplementation has got a beneficial effect in the diet of seabass and supplementation at 1% level is optimal for improving the growth.  相似文献   

14.
A feeding trial was conducted to estimate the optimum level of dietary n‐3 highly unsaturated fatty acids (HUFAs) for juvenile sea cucumber, Apostichopus japonicas, based on growth performance and fatty acid compositions. Diets with five n‐3 HUFAs levels (0.15, 0.22, 0.33, 0.38, and 0.46%) were fed to sea cucumber juveniles (1.97 ± 0.01 g) once a day for 60 d. The sea cucumbers fed diets containing 0.22% n‐3 HUFAs showed significantly (P < 0.05) higher body weight gain, feed efficiency, and protein efficiency ratio than the sea cucumbers fed diets containing 0.15% n‐3 HUFAs, but not significantly different (P > 0.05) from those of sea cucumbers fed diets containing 0.33, 0.38, and 0.46% n‐3 HUFAs. The sea cucumbers fed diets containing 0.46% n‐3 HUFAs showed significantly (P < 0.05) higher eicosapentaenoic acid and saturated fatty acid than the sea cucumber fed diets containing 0.15% n‐3 HUFAs, but not significantly different (P > 0.05) from those of sea cucumbers fed diets containing 0.22, 0.33, and 0.38% n‐3 HUFAs. The results of growth performance and n‐3 HUFA compositions of body wall indicated that the optimum level of dietary n‐3 HUFAs for juvenile sea cucumber is between 0.22 and 0.46%.  相似文献   

15.
A 6‐week feeding trial was conducted to examine the effect of feeding frequency on growth, feed utilization efficiency, body composition and waste output of juvenile golden pompano Trachinotus ovatus reared in net pens. Fish (10.3 ± 0.5 g) were either fed a formulated diet containing 48.4% crude protein and 5.7% crude lipid at 0.5, 1, 2, 3 or 4 meals per day or fed a raw fish feed at two meals per day as a control. The weight gain (WG) increased with increasing feeding frequency from 0.5 to 3 meals per day (P < 0.05), but did not significantly change with the further increase in feeding frequency from 3 to 4 meals per day (P > 0.05). The feed intake (FI) was lower in fish fed at 0.5 or 1 meal per day than in fish fed at 2, 3 or 4 meals per day (P < 0.05). No significant differences were found in the feed conversion ratio (FCR), nitrogen retention efficiency (NRE), condition factor (CF), nitrogen waste output (NWO) and phosphorus waste output (PWO) between fish fed at 1, 2, 3 or 4 meals per day (P > 0.05), whereas no significant difference was found in the phosphorus retention efficiency (PRE) among the feeding treatments (P > 0.05). The body lipid content increased, whereas the contents of moisture and ash decreased, with the increase in feeding frequency (P < 0.05). At the same feeding frequency, fish fed the formulated diet exhibited lower FI, FCR, HSI, body moisture content, NWO and PWO, but higher NRE, PRE, body lipid content and body phosphorus content than those of fish fed the raw fish feed (P < 0.05). These results suggest that the formulated diet can satisfy nutrient requirements of juvenile golden pompano reared in net pens, and the suitable feeding frequency is 3 meals per day.  相似文献   

16.
A 28‐week feeding trial was conducted in concrete tanks with Nile tilapia, Oreochromis niloticus (L.) with an average initial weight and length of 61.9±6.03 (g fish?1) and 17.6±0.45 (cm fish?1), respectively, to examine the effect of two protein levels and three feeding levels (% body weight (BW) day?1) on growth performance, production traits and body composition. Twelve 4‐m3 concrete tanks (2 × 2 × 1.25 m, long, width and height) were each stocked with 100 fish and fed diets containing either 25% or 30% crude protein at rates of 1%, 2% and 3% BW daily (2 × 3 factorial experiment). The results revealed that there was no significant increase in growth rate with increasing dietary protein levels, whereas there was significant increase in growth rate with increasing feeding levels (P≤0.05). The same trend was also observed for mean BW (g), mean body length (cm), production rate (kg m?3), specific growth rate (SGR % day?1), feed conversion ratio (FCR), condition factor (K) and survival rate (%). The best final mean BW (g), final mean body length (cm), SGR (% day?1), FCR, K, production rate (kg m?3) and survival rate (%) were recorded in groups of fish fed with 25% dietary protein at the 2% feeding level. Whole fish fat and energy contents were not significantly influenced (P>0.05) by protein levels and feeding levels. Protein and ash contents were significantly (P≤0.05) influenced by feeding level, but not by dietary protein level. Economic evaluation indicated that dietary protein 25% (diet A) at the 2% BW day?1 feeding level was the most cost‐effective and affordable feed strategy for farmers. We conclude that a 25% protein diet fed at 2% BW day?1 is recommended for adult Nile tilapia reared in concrete tanks.  相似文献   

17.
The present work aimed to study metabolic utilization of energy and protein by juvenile European seabass reared at 25 °C and to estimate maintenance requirements, based on indirect calorimetry and nitrogen excretion measurements. Duplicate groups of fish (IBW = 22 g) were fed a practical diet, for 28 days, at ration levels of 0, 0.25, 0.5, 1 and 1.5% of body weight. At the end of this period, oxygen consumption and ammonia nitrogen excretion were measured in fed and unfed fish. Weight gain linearly increased with ration level. Feed efficiency significantly increased with nitrogen intake up to 0.68 g N/kg/day. Nitrogen retention (% N intake) was positive at all feeding levels, being maximum at 0.5% BW and then decreased with increasing ration levels. There was negative energy balance at the lowest ration level and significantly increased at higher ration levels. Daily oxygen consumption (g/kg body mass) and ammonia excretion (mg N–NH4/kg body mass) significantly increased with ration level. Heat production and heat increment of feeding (kJ/kg/day) remained low at low ration levels and significantly increased as ration level increased from 0.5 to 1.5% BW. Below maintenance, protein energy represented 34% of total energy expenditure and significantly increased to 49–56% above maintenance. Based on indirect calorimetry and ammonia excretion data, maintenance energy and protein requirements were estimated to be 56.8 kJ DE/kg/day and 1.15 g DP/kg/day, respectively. The efficiencies of energy and protein utilization were estimated to be 0.83 and 0.66, respectively.  相似文献   

18.
Raw undehulled pigeon pea, Cajanus cajan, seeds were processed by toasting, boiling, and soaking before milling to produce pigeon pea meals (PPMs). African catfish, Clarias gariepinus, were fed eight diets formulated with these meals at two dietary inclusion levels of 600 and 650 g/kg in combination with fish waste meal levels of 350 and 330 g/kg, respectively, to yield a protein and energy contents of 35.96 ± 2.1% dry matter and 18.04 ± 0.2 kJ/g. Fish (mean weight 0.46 g) were weighed and distributed to 24 experimental tanks (seven fish per tank). Triplicate fish groups were fed restricted ration (5% of biomass) per day in two portions for 56 d in static water. Results showed that fish groups fed raw PPM diets had low body weight gain (BWG), inferior specific growth rate (SGR), and high feed conversion ratio (FCR) when compared to other feeding groups. The hematocrit, hemoglobin concentration, and red blood cell and white blood cell counts decreased significantly (P < 0.05) with raw PPM diets. Slight decrease also was recorded among groups fed diets of other processing methods when compared with initial fish. However, soaking for 16 h enhanced best fish BWG, SGR, FCR, and hematological values and can be recommended as a good processing method of PPM for African catfish diets.  相似文献   

19.
Quantitative l-lysine requirement of juvenile grouper Epinephelus coioides   总被引：3，自引：0，他引：3  
An 8‐week feeding trial was conducted to determine the quantitative lysine requirement of juvenile grouper Epinephelus coioides (initial mean weight: 15.84 ± 0.23 g, mean ± SD) in eighteen 500‐L indoors flow‐through circular fibreglass tanks provided with sand‐filtered aerated seawater by feeding diets containing six levels of l ‐lysine ranging from 19.2 to 39.5 g kg?1 dry diet in 4 g kg?1 increments. The diets, in which 250 g crude protein kg?1 diet came from fish meal and soybean protein concentrate, and 230 g kg?1 from crystalline amino acids, were formulated to simulate the amino acid profile of 480 g kg?1 whole chicken egg protein except for lysine. Each diet was assigned to three tanks in a completely randomized design. Grouper were fed to apparent satiation twice daily during the week and once daily on weekends. Weight gain and specific growth rate increased with increasing levels of dietary lysine up to 27.2 g kg?1 (P < 0.05) and remained nearly the same thereafter (P > 0.05). Feed efficiency was the poorest for fish fed the lowest lysine diet (P < 0.05) and showed no significant differences among other treatments (P > 0.05). Survival could not be related to dietary treatments. Body composition remained relatively constant except for lipid contents in muscle and liver. Total essential amino acid contents in liver increased with dietary lysine level although there was a slight decline for fish fed the highest lysine level of diet. Plasma protein content increased with increasing dietary lysine level (P < 0.05), but cholesterol, triacylglycerol and glucose contents were more variable and could not be related to dietary treatments. Dietary lysine level significantly influenced morphometrical parameters (condition factor, hepatosomatic index and intraperitoneal fat ratio) of juvenile grouper (P > 0.05). Broken‐line analysis of weight gain indicated the dietary lysine requirement of juvenile grouper to be 28.3 g kg?1 diet or 55.6 g kg?1 dietary protein.  相似文献   

20.
本实验以我国重要的海水养殖鱼类大黄鱼[初始体质量(13.57±0.33)g]为研究对象,在浮式网箱中进行为期8周的摄食生长实验,探讨饲料脂肪水平和投喂频率对大黄鱼生长、体组成及脂肪沉积的影响。采用3×2双因子实验设计,其中饲料脂肪水平分别为9%、12%和15%,投喂频率分别为2次/天和1次/天。结果表明:投喂频率对大黄鱼特定生长率(SGR)和饲料效率(FER)均有显著影响(P<0.05),而饲料脂肪水平仅对FER有显著影响(P<0.05)。2次/天投喂组的大黄鱼末体质量和SGR均显著高于1次/天投喂组,而饲料效率显著低(P<0.05)。在2次/天投喂时,各个饲料脂肪水平对SGR和FER没有显著影响(P>0.05)。而在1次/天投喂时,随着饲料脂肪水平的提高,SGR和FER均显著提高(P<0.05)。2次/天投喂组的大黄鱼全鱼水分含量显著低于1次/天投喂组,而粗脂肪含量显著高(P<0.05)。大黄鱼全鱼粗脂肪含量随着饲料脂肪水平的增加而显著升高(P<0.05)。然而在1次/天投喂时,饲料脂肪水平未对全鱼体粗脂肪含量产生显著影响(P>0.05)。大黄鱼的肝脏和肌肉脂肪含量、肝体比(HSI)以及脏体比(VSI)受到了饲料脂肪水平的显著影响(P<0.05)。在2次/天投喂时,肝脏和肌肉脂肪含量、HSI以及VSI随饲料脂肪水平的升高而显著增加(P<0.05);而在1次/天投喂时,各个饲料脂肪组大黄鱼肝脏和肌肉脂肪含量、HSI以及VSI均无显著差异(P>0.05)。饲料脂肪水平和投喂频率仅对大黄鱼的生长、饲料效率的影响存在显著的交互作用(P<0.05),而对大黄鱼体组成、形态学指标以及肝脏和肌肉脂肪含量无显著的交互作用(P>0.05)。  相似文献   

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