Carcass Crude Protein Research Articles

Effects of Abelmoschus esculentus leaf as binder in the diet of Oreochromis niloticus fingerlings

Abstract. The experiment was conducted to assess the use of Abelomoschus esculentus leaves soaked for 24 hours as binders in the production of fish feed pellets. Physical properties and dietary effects of the diets were assessed. There was no significant difference (P>0.05) in the sinking rate (cm.sec-1) and bulk density (g/cm3) of experimental diets. There were significant differences (P<0.05) in the thickness strength (mm), water absorption index, hardness (mm) and water stability (%) of experimental diets. Diets MAA and MAW had the highest water stability (88.90±0.46%) while the lowest one was in diet MAI (85.20±0.10%). There was a significant difference (P<0.05) in the friability of experimental diets at different revolution speeds. The highest protein retention was recorded in diet MAI (95.83%) and the lowest one was in diet WHH (91.24%). There was no significant difference (P>0.05) in the mean final weight, mean weight gain, specific growth rate, feed conversion ratio, and feed efficiency of experimental fish-feed experimental diets. Diet MWA had the lowest FCR, the highest FER and SGR. There was a significant difference (P<0.05) in the crude protein, fat, and ash content of carcass of fish fed experimental diets. Fish fed diet MWA had the highest carcass crude protein content (49.27±1.51) and the lowest one was in diet WHE (47.15±0.24). The results showed that A. esculentus leaves can be used as a binder in the production of quality fish feed pellets.

Effects of dietary fermented Saccharomyces cerevisiae extract (Hilyses) supplementation on growth, hematology, immunity, antioxidants, and intestinal health in Nile tilapia

This study investigated the effects of dietary supplementation with the product Hilyses on growth performance, feed utilization, nutrient composition, hematological parameters, serum biochemistry, immune function, antioxidant status, and digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, initial body weight 4.24 ± 0.01 g). The fish were fed diets supplemented with Hilyses at concentrations of 0, 1, 2, or 3 g/kg for a period of 8 weeks. The results showed that supplementation with Hilyses at levels up to 2 g/kg diet significantly improved final body weight, weight gain, specific growth rate, feed efficiency ratio, protein efficiency ratio, apparent protein utilization, and energy utilization compared to the control diet without Hilyses. Carcass crude protein content and moisture were significantly higher in Hilyses-fed groups, while crude lipid content decreased at the 3 g/kg supplementation level. Hilyses supplementation enhanced various hematological parameters, including increased red blood cell count, total leukocyte count, hemoglobin concentration, hematocrit, and mean corpuscular volume. Serum biochemistry and immune function markers like total protein, albumin, complement component C3, IgM, and IgG were significantly elevated in the 2 and 3 g/kg Hilyses groups. Antioxidant enzyme activities (catalase, glutathione peroxidase, total superoxide dismutase) were enhanced, and lipid peroxidation was reduced, in the 2 g/kg Hilyses group. Digestive enzyme activities, particularly protease and lipase, were also improved with Hilyses supplementation. Histological examination showed reduced lipid deposition in the liver and increased branching of intestinal villi at the 2 g/kg Hilyses level. Overall, these results indicated that dietary Hilyses supplementation at 2 g/kg diet optimizes growth, feed utilization, nutrient composition, hematology, immunity, antioxidant status, and digestive function in juvenile Nile tilapia.

Effect of feeding semi-moist diet as a practical strategy to reduce feed costs in tilapia juvenile production

Tilapia (Oreochromis niloticus) is one of the species with the greatest increase in production worldwide. However, the continuous increase in the price of ingredients, and consequently in the diet costs may limit the expansion of the sector. Several alternatives to reduce feed costs are currently under study, as the use of practical press-pellet semi-moist diet that can be manufactured on farm. This study evaluates five levels of replacement (0, 25, 50, 75, and 100%) of a commercial diet by a practical (press-pellet semi-moist) diet and its effect on zootechnical performance, carcass proximate composition, as well as somatic and economic indexes in tilapia juveniles (9.48 g). After 56 days, survival and condition factor did not differ significantly between treatments. Final weight, daily weight gain, feed conversion, and specific growth rate had a negative linear effect as the practical diet increased, while carcass yield had a positive linear effect. Carcass crude protein content was higher in fish fed with 100% practical diet, while crude lipid had the lowest content in this same treatment. As for economic indexes, the estimated cost of feeding decreased as a function of the practical diet inclusion, with a final saving of US$ 8.68 per thousand of juveniles produced (100% replacement).

Influence of Antox® Probiotic, as Water Additive on Growth Performance, Nutrient Utilizatiion and Body Composition of the African Catfish, Clarias Gariepinus (BURCHEL, 1822) Fingerlings

The study was carried out for three (3) months to determine the influence of a commercial probiotic Antox® which is a mono- strain probiotic consisting of live Saccharomyces cerevisiae at 4.125 × 106 cfu per 100ml on growth, nutrient utilization and body composition of Clarias gariepinus fingerlings. Fish fingerlings (7.6 – 7.9g) were randomly distributed into five triplicate treatment groups in fifteen plastic tanks (80L) at a stocking density of ten (10) fish per tank. The probiotic was administered in the culture water of the treatment groups; 0mls (control, T0), 0,5ml (T1), 1.0 (T2), 1.5 (T3), 2.0 (T4) ml probiotic/80l. Water quality parameters were regularly monitored. The growth performance, nutrients utilization and body composition of C. gariepinus fingerlings between probiotic treated groups were significantly increased (P < 0.05) with increasing dosage of the probiotic. The best Final Mean Weight (121.3g), Mean Weight Gain (113.5g), Percentage Mean Weight Gain (1456.5g), Feed Conversion Ratio (0.92g) and Protein Efficiency Ratio (2.6g), were recorded in probiotic treatment group T4 (2.0ml). Similarly, the highest increase in carcass crude protein (69.9g), moisture (10.34), ash (15.26g) and dry matter (29.46) were recorded in treatment group T4 (2.0ml). Probiotic (Antox®) is recommended for administration in C. gariepinus fingerlings culture water at 2.0mls/ 80L.

INFLUENCE OF YEAST-BASED COMMERCIAL PROBIOTIC ON GROWTH PERFORMANCE, NUTRIENT UTILIZATIION AND BODY COMPOSITION OF THE AFRICAN CATFISH (Clarias gariepinus) FINGERLINGS

The study was carried out for three (3) months to determine the influence of a commercial probiotic which is a mono- strain probiotic consisting of live Saccharomyces cerevisiae at 4.125 × 106 cfu per 100ml, on growth, nutrient utilization and body composition of Clarias gariepinus fingerlings. At a stocking density of ten (10) fish per tank, fish fingerlings (7.6–7.9g) were randomly dispersed into five treatment groups with three repetition per group, consisting of fifteen plastic tanks (80L). The probiotic was administered in the culture water of the treatment groups; 0mls (control, T0), 0.5ml (T1), 1.0 (T2), 1.5 (T3), 2.0 (T4) ml probiotic/tank (80L capacity). Water quality parameters were regularly monitored. The growth performance, nutrients utilization and body composition of C. gariepinus fingerlings among probiotic treatments groups were significantly increased (P < 0.05) with increasing dosage of the probiotic. The best Mean Weight (121.3g), Mean Weight Gain (113.5g), Percentage Mean Weight Gain (1456.5%), Feed Conversion Ratio (0.92g) and Protein Efficiency Ratio (2.6), was recorded in probiotic treatment group T4 (2.0ml). Similarly, the highest increase in carcass crude protein (69.9g/Kg), moisture (10.34), ash (15.26g/Kg) and dry matter (29.46g/Kg) was recorded in treatment group T4 (2.0ml). Probiotic (Antox®) is recommended for administration in C. gariepinus fingerlings culture water at 2.0mls per 80L.

Effect of different stocking densities and vitamin c supplementation for piaractus mesopotamicus / Efeito das diferentes densidades de estoquecimento e fornecimento de vitamina c para piaractus mesopotamicus

The objective was to evaluate the effects of stocking density and vitamin C supplementation under the zoo-technical, blood and bromatological parameters of juvenile Piaractus mesopotamicus. A hundred and eighty fish (10.64±1.26g) were randomly distributed in 24 boxes and two stocking densities (0.89 and 1.77kg/m³), fed for with commercial feed (60 days), supplemented with three levels of vitamin C (0, 0.5, and 1.5 g/kg of feed), in a 2x3 factorial scheme, with four repetitions. At the end of the experiment, all fish were anesthetized to collect the zoo-technical data. Three animals from each repetition were selected for blood collection, and then, all animals were euthanized and processed to determine the bromatological parameters. There was interactive effect between the vitamin C levels and the stocking densities in the blood hematological parameter and in the carcass crude protein (p<0.05). There was no effect of the vitamin C supplementation levels for the evaluated zoo-technical, hematological and bromatological parameters. The density influenced on the weight gain, average final weight, specific growth rate, total and standard length. It is concluded that the vitamin C did not present alteration in the studied variables, however, the recommended stocking density for the species in this study is 0.89 kg/m³.

Haematological Indices and Carcass Composition of African Catfish Clarias gariepinus (Burchell, 1822) Fingerlings Fed with Fluted Pumpkin Leaf (Telfairia Occidentalis) as Feed Additives

A feeding trial was carried out for 56 days to ascertain the effects of Telfairia occidentalis (fluted pumpkin) as a feed additive on the haematological profile and nutrients value of Clarias gariepinus carcass. C. gariepinus fingerlings (mean body weight 9.6g) were randomly distributed in plastic bowls at nine fish per bowl in triplicates. Five diets designated as D1 to D5 with 40% crude protein containing 0, 50, 100, 150, and 200g/kg of T. occidentalis leaf powder were fed to C. gariepinus fingerlings at 5% body weight per day. The results showed that T. occidentalis additive significantly (P≤0.05) improved the haematological parameters of the fish. The mean value of white blood cells (WBC) count (μL) in the diets fed with T. occidentalis were significantly higher (D2-D5 : 870.20, 864.80, 840.30, 876.40, respectively) than the diet without T. occidentalis (D1 783.15). A similar trend was observed in PCV, MCV, MCHC, MCH, and platelets. However, HB D1 (control) had higher values than the diet containing T. occidentalis. Meanwhile, in carcass quality, there was an increase in the crude protein of all the fish but the group that consumed T. occidentalis had a higher carcass crude protein and lower lipid, while the control had a higher lipid value. Meanwhile, the initial values obtained before the feeding trials had lower crude protein and higher lipid value when compared with the fish that was fed with the experimental diet. In conclusion, T. occidentalis leaf meal can be utilized to improve the haematological parameters of the fish, with an increase in the WBC there is a high possibility of the fish to withstand pathogenic attacks because Blood is a major parameter that determines the physiological, immune , and nutritional status of an organism, also WBC are important blood constituents for defense against diseases, pathogens and unwanted foreign bodies in an organism.

Sensory Attributes, Microbial Activity, Fatty Acid Composition and Meat Quality Traits of Hanwoo Cattle Fed a Diet Supplemented with Stevioside and Organic Selenium.

This study examined the effects of stevioside (S) and organic selenium (O-Se) supplementation on the sensory attributes, microbial activity, fatty acid composition, and meat quality traits of Hanwoo cattle (Korean native cattle). Twenty-four Hanwoo cattle (663 ± 22 kg body weight) were assigned to two dietary treatments for 8 months: control diet and 1% stevioside with 0.08% organic selenium supplemented diet. S and O-Se inclusion in the diet enhanced the final body weight, weight gain, and carcass crude protein (p < 0.05). Moreover, supplementation with S and O-Se had a significant effect on lowering the drip loss and shear force and enhanced the a* (redness) of the longissimus dorsi muscle (p < 0.05). The inclusion of dietary S and O-Se improved the sum of the polyunsaturated fatty acid (ΣPUFAs) content of the meat, and the oxidative status (TBARS) values during second week of storage decreased by 42% (p < 0.05). On the other hand, the microbial count tended to decrease (7.62 vs. 7.41 log10 CFU), but it was not significant (p > 0.05), and all sensory attributes were enhanced in the S and O-Se supplemented diet. Overall, these results suggest that supplementation of the ruminant diet with stevioside and organic selenium improves the growth performance, carcass traits, and meat quality with enriched PUFAs profile and retards the lipid oxidation during the storage period in beef.

Shade or unshaded effects on body composition of growing Afshari lambs during summer

Abstract To evaluate the effect(s) of the heat stress (HS) on body composition thirty-two growing Afshari lambs were randomly housed outdoor (OUT) without access to shade (mean temperature humidity index = 74.98) or kept indoor (IN) under shade (mean temperature humidity index = 73.08). At the end of study 10 lambs were processed and separable body protein and fat were determined. Neither morning rectal temperature nor morning respiratory rate were influenced by treatments, but both were increased in OUT lambs at evening measurement; the evening rectal temperature was higher in OUT lambs and they had more evening respiration rate (48 ± 1.4 more breath per minute). While there was no difference between treatments in carcass weight, fat-tail weight as a percent of cold carcass weight tended to be lighter (P = 0.13) for OUT lambs (15.17 %) than for IN lambs (18.77 %). Carcass separable fat with and without fat-tail showed no effect of treatments. Carcass EE was not influenced by environment. Carcass crude protein percentage was greater for OUT (16.64 %) than for IN lambs (15.17 %; P

Earthworm, Eisenia fetida , bedding meal as potential cheap fishmeal replacement ingredient for semi‐intensive farming of Nile Tilapia, Oreochromis niloticus

The study amalgamated earthworm and agro‐industrial wastes through vermicomposting and then evaluated the potential of the bedding (mixture of Eisenia fetida and vermicompost) to replace fishmeal in semi‐intensive farming of Oreochromis niloticus. The bedding was used to substitute fishmeal at inclusion rates of 100, 60, 30 and 0% (D100, D60, D30 and control D0). In triplicates, the four homogeneous diets were fed to quadruplicate groups of 30 g O. niloticus for 112 days. There was no significant difference (p > .05) in mortalities, average length gain and FCR among all tests. Nevertheless, diet D0 had significantly (p < .05) superior amino acid profile, low fibre content and fish carcass crude protein (63.2 ± 0.72% dry matter). Subsequently, D30 and D0 produced fish with significantly higher (p < .05) mean weight gain (256.03 ± 0.4 g) and biomass (369,136 g) respectively. On to the contrary, diet D100 had significantly higher (p < .05) crude lipids content (9.4 ± 0.6% dry matter), economic returns and profit index than the control diet due to the comparatively low cost of producing the earthworm bedding. This simple biotechnology can commercially be upscaled to sustainably produce cheap and nutritious fish feed capable of increasing yields and maximizing profits.

The growth and nutrient utilization of Clarias gariepinus (Burchell 1822) fed Parkia biglobosa meal based diet.

The study investigated the growth and nutrient utilization of Clarias gariepinus fingerlings fed five iso-nitrogenus diets, containing fermented locust bean meal, at varying inclusion level (0%, 10%, 20%, 30%, 40%, 50%) as replacement for fishmeal. Eight weeks feeding trial was conducted using Clarias gariepinus fingerlings which were randomly distributed into 12 bowls at a stocking rate of 20 fish per bowl, in replicates per treatment. The experimental design was completely randomized. The fish were fed at 5% body weight, twice daily. Six isonitrogenous (35% crude protein) diets containing fermented locust beans meal at varying replacement level for fish meal designated as diet A0, B10, C20, D30, E40 and F50 were formulated and fed to the fish. All the experimental fish fed the various treatments showed increase in weight, carcass crude protein and lipid content, compared to the initial value indicating positive contribution of the various diets to growth of the fish. The results obtained indicated there was no significant difference (P>0.05) in the mean weight gain, percentage weight gain. Specific growth rate, food conversion ratio and protein efficiency ratio among the fish fed the various diets. The highest weight gain was recorded in the fish fed the control diet (2.47g) while the least was recorded for the fish fed the B20 diet (2.18g). This study revealed that locust bean seed if processed, as in fermentation, could replace fishmeal up to 50% level in the diet of C. fish. This level of inclusion would be a significant replacement for the expensive fishmeal in feed manufacturing.

Effect of environmental regulated water temperature variations on survival, growth performance and haematology of African catfish, Clarias gariepinus

A 56 day study was carried out to evaluate effect of temperature changes on survival, growth performance and haematology of Clarias gariepinus fingerlings fed housefly maggot meal (magmeal) diet. Ninety (90) Clarias gariepinus fingerlings, (initial mean weight 4.33±0.03g) were subjected to different environmental regulated temperature conditions in three locations (laboratory, outdoor, greenhouse). The observed average temperature was 26.53±0.01°C, 26.06±0.01°C and 31.52±0.00°C for laboratory, outdoor, greenhouse, respectively. Ten fingerlings stocked per experimental tank were fed in triplicates at 5% body weight in two portions per day. It was observed that different water temperatures affected fish growth. All experimental fish in the greenhouse died after 8 days of exposure. This happened around 14.00 hrs when water temperature reached 40°C. There was no significant difference (P&lt;0.5) in final weight, weight gain, food conversion ratio and standard growth rate among the fish reared in the laboratory (26.53°C) and outside tanks (26.06°C), respectively. The initial carcass crude protein (Cp) value was 58.97%. At the end of the experiment fish reared in the laboratory had a crude protein value of 63.97±0.06% Cp and those reared outdoor (26.06°C) had 71.28±0.00% Cp. No significant difference in values of packed cell volume; white blood cell; haemoglobin and mean corpuscular haemoglobin concentration was found between fish reared in laboratory (26.53°C) and outside (26.06°C). However, the red blood cell (RBC); mean corpuscular haemoglobin and mean corpuscular volume showed significant difference (P&gt;0.05). The result confirms that Clarias gariepinus fingerlings reared at a mean temperature of 26°C (within the recorded optimal temperature range for good growth) performed well. Clarias gariepinus fingerlings are not able to survive when water temperature reaches to 40oC.

Effects of soybean and sunflower meals on the growth, feed utilization, and gene expression in two Canadian strains of juvenile Arctic charr (Salvelinus alpinus)

The effects of graded levels (0–20% total dietary inclusion) of commercial, solvent-extracted soybean meal (SBM) and expeller sunflower meal (SFM) were investigated on growth, nutrient utilization, and pro-inflammatory gene expression in the distal intestine and spleen of two commercial Canadian strains (Strain 1 and Strain 2) of Arctic charr. Five experimental diets with increasing inclusion of SBM or SFM were fed for 84days to two Canadian strains of Arctic charr (initial body weight=9g/fish). Feeding these diets resulted in no differences in growth rate (measured as final weight or thermal-unit growth coefficient, TGC) in the two strains. Increased inclusion level of plant proteins negatively affected FE (P<0.0001) with effects most commonly observed in groups fed SBM-based diets. The effect of the ingredient was significant (P<0.05) on PXR gene expression in the distal intestine; PXR expression was higher with SBM than with SFM. The effect of the inclusion level of plant ingredients was significant (P<0.05) on IL-Iβ gene expression in the spleen. Feed intake, FE, NRE, ERE, whole body crude protein, lipid, gross energy, and organo-somatic indices were significantly (P<0.05) affected by genetic strain examined. Strain 2 exhibited higher FE and carcass crude protein content and lower carcass lipid content. The difference in FE, protein and lipid content for the 2 genetic strains of charr may indicate variations in efficiency for protein and lipid utilization, with a potential protein-sparing effect of dietary lipid noted in Strain 2.

Influence of dietary biotin levels on growth and non-specific immune response in large yellow croaker,Larimichthys croceaR

A 9-week feeding experiment was conducted to determine the effect of dietary biotin levels on growth performance and non-specific immune response of large yellow croaker. Fish (6.16 ± 0.09 g) were fed twice daily to apparent satiation with diets containing 0.00 (as the basal diet), 0.01, 0.05, 0.25, 1.24 and 6.22 mg biotin kg−1 diet. Results showed that fish fed the basal diet had the lowest survival rate, and fish fed 0.05 mg kg−1 dietary biotin achieved significantly higher final weight and weight gain. Dietary biotin levels had no significant influence on carcass crude lipid, moisture and ash content, but significantly influenced the carcass crude protein. Liver biotin concentration significantly increased with the supplementation of biotin, but no tissue saturation was found within the supplementation scope of biotin. Broken-line regression analysis of weight gain showed that juvenile large yellow croaker requires a minimum dietary biotin of 0.039 mg kg−1 for maximal growth. The analyses of serum parameters showed that the moderate- (0.05 mg kg−1) and high-dose (6.22 mg kg−1) dietary biotin significantly improved both lysozyme and alternative complement pathway activities, indicating dietary biotin within a certain range could improve the non-specific immune response of large yellow croaker.

Broiler responses to digestible threonine at different ages: a neural networks approach.

Three experiments were conducted with broiler chickens to evaluate the effects of digestible threonine (DThr) and crude protein (CP) on their performance at three different phases of age: 1-14, 15-28 and 29-42days. The measured traits included the following: average daily gain (ADG), feed intake (FI), feed conversion ratio (FCR), carcass crude protein (CCP), body lipid (BL), feather weight gain (FWG), protein deposited in feather (FCP), carcass plus feather protein (CFCP), carcass Thr deposition (CDThr) and nitrogen excretion (NE). A dilution technique was used to create seven diets (with eight replicates) increasing the DThr content from 1.5 to 10g/kg of diet for phase 1, 1.3-8.9g/kg of diet for phase 2, and 1.2-8.2g/kg of diet for phase 3. Data measured were imported into neural networks (NNs) to: (i) predict the measured traits in response to DThr and CP, (ii) rank the importance of DThr and CP on these traits through sensitivity analysis and (iii) find the optimal levels of DThr and CP that lead to the desired (maximum or minimum) responses. For each trait investigated, 50 different random groups of data were generated using a bootstrapping method. These 50 data groups were then used to develop 50 separate NNs which were subsequently combined to construct the final ensemble NN model. In general, accuracy of the models constructed was acceptable, although models of high (ADG, FCR, CFCP, BL, DThr and NE; 0.64≤R(2) ≤0.99) and low (CCP, FWG and FCP; 0.26≤R(2) ≤0.79) accuracy were obtained. All models developed showed the greatest sensitivity to DThr. This may be explained by the dilution technique diet preparation used in these experiments. Optimization results showed decreases in optimal values of DThr and CP with increasing age for all traits. The highest level of DThr was suggested for minimum BL, followed by minimum FCR, maximum ADG, maximum CFCP, minimum NE and maximum CCP respectively. Results showed that the optimal values of DThr for minimum FCR in phases 1-3 were 8.5, 7.4 and 6.4g/kg of diet, while these values for maximum ADG were 8.2, 7.2 and 6.4g/kg of diet respectively.

Effect of different sources and levels of some dietary biological additives on: III- body composition and muscular histometric characteristics of Nile Tilapia, Oreochromis niloticus

This study aimed to investigate the effect of dietary graded levels of Aqua Superzyme, Garlen Allicin, and Diamond V (Original XPC) on the chemical composition and histometric parameters of males Nile tilapia Oreochromis niloticus. The carcass composition concerning their DM, CP, and EE contents are increased by age advance, but the ash percentages decreased. At the end of the experiment (16 weeks), DM did not significantly (P≥0.05) influence by all dietary treatments; yet, 0.01% of the diet of either the 1 st two substances was responsible for the highest CP and ash percentages and the lowest EE and energy contents. Moreover, 0.5% of the diet of the 3 rd substance gave the highest (P≤0.05) level among its tested levels concerning CP and the lowest (P ≤0.05) EE and energy contents, but ash was not affected (P≥0.05). The best treatment (highest carcass crude protein and lowest ether extract percentages) was feeding fish the diet containing Diamond V-Original XPC at 0.5% of the diet. The same probiotic at the same level led also to improve most of the histometric characteristics of the dorsal muscles. So, it could recommend the dietary inclusion of the probiotic Diamond V-Original XPC at 0.5% of the tilapia diet.

Effect of diet dilution ratio at early age on growth performance, carcass characteristics and hepatic lipogenesis of Pekin ducks

This study was conducted to test the hypothesis that proper diet dilution ratio at early age might improve feed conversion ratio (FCR) and reduce body fat deposition of meat-type ducks. One hundred and fifty 1-day-old male and female White Pekin ducks (44.5±1.0 g) were randomly assigned into three treatments with five replicates (pens) of 10 birds each, respectively representing the experimental diets with 0 (control), 40 or 60% rice hulls inclusion in the basal diet between 8 and 14 d of age. The basal diet was fed before and after this period. The results showed that diluting the diet with 40% rice hulls increased (p 0.05) as the controls at 42 d of age. The diet diluted with 60% rice hulls resulted in lower (p < 0.05) body weight at market age than the other treatments. The diet with 40% rice hulls reduced (p < 0.05) skin with fat and abdominal fat pad, crude fat content in the carcass and in breast meat, and increased (p < 0.05) carcass crude protein at 42 d of age. These changes may be explained by the lower (p < 0.05) activities of hepatic malic dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6-PDH) and fatty acid synthetase (FAS) enzymes both at 14 and 42 d of age in birds fed the diluted diets relative to the control birds. The results of this study indicate that feeding diets diluted with 40% rice hulls to Pekin ducks between 8 to 14 d of age may induce compensatory growth during the following recovery period, and may be used to improve FCR and to reduce body fat deposition at market age.

Effect of dietary protein, lipid and carbohydrate contents on the growth, feed efficiency and carcass composition of Cyprinus carpio communis fingerlings

This study aimed to determine a feed formulation with best protein to energy ratio which would result in better growth, feed efficiency and carcass composition of Cyprinus carpiocommunis. Fingerlings having average weight 1.64 ± 0.13 g and length 5.26 ± 0.10 cm were fed on four different formulated feeds and a control feed (each in a triplicate set), 6% of their body weight, three times a day, during 90 days. Feeds were formulated using ground nut oil cake, mustard oil cake, rice bran, wheat bran, fish meal and soybean meal in order to suffice the balanced need of protein and energy of the Common carp. Growth, feed efficiency and carcass composition were measured. At the end of the study, the growth, feed efficiency and carcass composition of fingerlings was affected significantly (P < 0.05) with protein, lipid and carbohydrate contents in the feeds. Highest growth, best feed conversion ratio, best protein efficiency ratio, highest carcass dry matter, crude protein, crude lipid, ash and energy content, lowest moisture content and carbohydrate content were observed in fingerlings fed with Feed B which contained 40 ± 0.21% protein, 9.31 ± 0.25% lipid and 10.08 ± 0.10% carbohydrate. The fingerlings fed with Feed C which contained 25.98 ± 0.19% protein, 5.49 ± 0.18% lipid and 34.63 ± 0.19% carbohydrate showed least growth, poor feed conversion ratio, poor protein efficiency ratio, least carcass dry matter, crude protein, crude lipid, ash and energy content, highest moisture content and carbohydrate content. This work concluded that a diet containing 40% protein, 9.31% lipid and 10.08% carbohydrate is the best one for a more profitable and successful culture of the Common carp. Key words: Protein to energy ratio, carp production, growth, feed efficiency, carcass composition.

Altered Growth Rates, Carcass Fatty Acid Concentrations, and Tissue Histology in First‐Feeding Steelhead Fed a Fish‐Meal‐ and Fish‐Oil‐Free Diet

AbstractA 12‐week feeding trial was conducted to evaluate a fish‐meal‐free, fish‐oil‐free diet for use with first‐feeding steelhead Oncorhynchus mykiss. The marine‐based control diet (marine diet) contained sardine (Sardinops spp.) meal and pollock (Pollachius virens) liver oil as the primary sources of protein and lipid, respectively. The experimental diet (terrestrial diet) contained only terrestrial sources of protein (poultry by‐product meal, blood meal, canola, corn gluten, and wheat gluten) and lipid (canola oil and flaxseed oil). Each diet was administered to five replicate groups of first‐feeding fry. At the conclusion of the feeding trial, fish that were fed the marine diet exhibited significantly higher weight gain and feed efficiency than fish that were given the terrestrial diet. Survival was not significantly affected by dietary treatment. However, fish that received the terrestrial diet exhibited significantly lower hemoglobin concentration and percent packed cell volume. Histological examination indicated that in comparison with control fish, steelhead that were fed the terrestrial diet exhibited a lesser degree of vacuolation in hepatocytes, mild hypertrophy and hyperplasia of the nephron tubular epithelium, and intracellular vacuolation in epithelium of the pyloric caeca. Carcass crude protein concentration was significantly higher in fish that were fed the marine diet than in fish that were fed the terrestrial diet. After 2 weeks of feeding, steelhead that received the marine diet exhibited significantly higher carcass concentrations of 14:0, 16:0, 16:1, 20:1, 20:5(n‐3), 22:5(n‐3), and 22:6(n‐3) fatty acids but significantly lower carcass concentrations of 18:1, 18:2(n‐6), 18:3(n‐6), 18:3(n‐3), and 20:4(n‐6) relative to fish that were given the terrestrial diet. These differences in carcass fatty acid concentrations persisted throughout the feeding trial. Results of this study indicate that the current terrestrial‐based diet is not a satisfactory replacement for the standard marine‐based diet used with first‐feeding steelhead.Received January 21, 2010; accepted January 22, 2011

Potential of Several Protein Sources as Fish Meal Substitutes in Diets for Large Yellow Croaker, Pseudosciaena crocea R

A feeding experiment was conducted to evaluate the potential of replacing fish meal (FM, Diet 1) with soybean meal (SBM, Diet 2), meat and bone meal (MBM, Diet 3), poultry by‐product meal (PBM, Diet 4), and peanut meal (PM, Diet 5) in practical diets of juvenile large yellow croaker, Pseudosciaena crocea. Five isonitrogenous and isoenergetic diets (43% crude protein and 20 kJ/g gross energy on dry matter basis) were formulated. Diet containing FM as the main protein source was used as a control (Diet 1). Diets 2–5 had 30% of the FM protein replaced with SBM, MBM, PBM, or PM protein. Each diet was randomly assigned to triplicate groups of 25 fish per cage (initial body weight 23.3 ± 0.96 g). Fish were maintained in sea floating cages (1.5 × 1.5 × 2.0 m), water temperature ranged from 27 to 30 C, salinity from 25 to 28‰ and dissolved oxygen content was more than 7 mg/L. Fish were hand‐fed twice daily to apparently satiation for 8 wk. Fish fed Diets 1–4 showed no significant difference in survival, weight gain (WG) and specific growth rate (SGR), while fish fed Diet 5 showed significant inferior WG and SGR (P &lt; 0.01). Carcass crude protein and crude lipid of the fish fed Diet 5 were significantly lower than those of the fish fed the other diets (P &lt; 0.05). Carcass lysine content of the of fish fed Diet 5 showed slight, yet significantly decrease (P &lt; 0.05), compared with those of the fish fed Diets 1–4, while other essential amino acids (EAAs) content showed no significant differences among the different treatments. Results of the present study indicate that about 30% of FM protein can be replaced by SBM, MBM, or PBM protein in large yellow croaker diets without adversely effecting growth.