Apparent Protein Digestibility (apparent + protein_digestibility)

Distribution by Scientific Domains


Selected Abstracts


Evaluation of In Vitro Apparent Protein Digestibility by Shrimp Using Gut Enzyme Extracts

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2009
Joe M Fox
Knowledge of apparent protein digestibility (APD) is required for optimization of feed formulae for the production of marine penaeid shrimp. The purpose of this study was to evaluate an in vitro method for determining APD in marine penaeid shrimp using gut enzyme extracts. A high correlation (r2 = 0.95) was shown between single-ingredient APD values for fish meal diets using in vivo methodology and those derived from in vitro testing of ingredients. A second study showed positive correlation (r2 = 0.71) between in vitro APD of selected purified and semipurified ingredients and their reported in vivo APDs. This correlation was much higher for purified ingredients (r2 = 0.93) versus less-refined ingredients (r2 = 0.24). A third trial compared in vitro APD at three different enzyme extract pH values and showed that for most protein sources, APD was significantly highest (P < 0.05) at pH = 7.0 and lower at pH = 6.1 or 7.9, indicating a neutral pH optimum for this methodology. [source]


Apparent Digestibility Coefficients of Various Feed Ingredients for Grouper Epinephelus coioides

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2004
Heizhao Lin
Apparent digestibility coefficients (ADC) of dry matter, crude protein, lipid, gross energy, amino acids, and fatty acids in white fish meal, brown fish meal, soybean meal, peanut meal, and yeast were determined for grouper Epinephelus coioides. Apparent digestibility was determined using a reference diet with 0.5% chromic oxide indicator and test diets that contained 70% reference diet and 30% of the feed ingredient being evaluated. The fish, averaging 12.0 g, were held in 250-L tanks at a density of 30 fish per tank. Feces were collected from three replicate groups-of fish. Apparent dry matter digestibility of ingredients was 78.85 ▒ 2.43, 79.11 ▒ 0.61, 69.85 ▒ 3.60, 73.67 ▒ 2.30 and 57.70 ▒ 4.69% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. Apparent gross energy digestibility of ingredients was 93.27 ▒ 2.90, 89.48 ▒ 1.78, 70.52 ▒ 4.01, 73.13 ▒ 2.41 and 51.67 ▒ 2.01% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. Apparent protein digestibility of ingredients was 89.82 ▒ 1.24, 87.34 ▒ 1.25, 83.97 ▒ 1.92, 80.79 ▒ 1.95, and 61.14 ▒ 0.54% for white fish meal, brown fish meal, soybean meal, peanut meal, and yeast, respectively. White fish meal and brown fish meal showed higher protein digestibility among ingredients tested (P ▒ 0.01). Lipid digestibility of ingredients was high (90.66-94.48%) and not significantly different except for yeast. Amino acid availability values for test ingredients were similar to values of protein digestibility. Amino acid availability values of white fish meal and brown fish meal were higher than other ingredients. Fatty acid availability values for test ingredients were similar to values of lipid digestibility. In general, the digestibility of most fatty acids was over 80% in all ingredients, except for 14:0 in yeast and 18:0 in peanut meal, PUFA + HUFA > MUFA > SFA. Longer-chain saturated fatty acids were less digestibility, except for 14:0, with digestibilities diminishing as fatty acid chain length increased. Apparent digestibility of dry matter, crude protein, lipid, gross energy, amino acids, and fatty acids in yeast was the lowest among the ingredients. [source]


Apparent digestibility of nutrients and energy in extruded diets from cultivars of barley and wheat selected for nutritional quality in rainbow trout Oncorhynchus mykiss

AQUACULTURE NUTRITION, Issue 3 2009
T.G. GAYLORD
Abstract A digestibility trial was conducted to elucidate potential differences in barley (Hordeum vulgare L.) lines and varieties as a first step in defining their potential for use in aquafeeds. A diverse group of six barley lines having six combinations of selected attributes, normal versus low phytic acid, normal versus waxy, and hulled versus hull-less, were chosen for evaluation along with a waxy wheat (Triticum aestivum L.) and soft white wheat. The experimental diets were manufactured by cooking extrusion and consisted of a 70% reference diet that was formulated to contain a minimal level of phosphorus and 30% test ingredient. Phosphorus availability ranged from 17 to 78% and was influenced by starch type in wheat. Apparent protein digestibility ranged from 53 to 125% and differences were observed between wheat varieties based on starch type. Apparent energy digestibility ranged from 32 to 63%, with waxy barley varieties having higher energy digestibility coefficients than normal starch varieties. Waxy starch varieties had higher starch digestibility in both barley and wheat because of the greater digestibility of amylopectin than amylose. In summary, the higher energy digestibility of waxy barley lines suggests that these varieties warrant further attention as feed ingredients for rainbow trout. [source]


Soybean protein concentrate as a protein source for turbot Scophthalmus maximus L.

AQUACULTURE NUTRITION, Issue 4 2000
O.J. Day
In the first of two experiments, the effect of a gradual substitution of dietary fish meal with soybean protein concentrate (SPC) on growth, feed consumption and protein digestibility was examined in 13 g turbot Scophthalmus maximus. Five isonitrogenous and isoenergetic diets (50% protein and 22 kJ g,1) containing SPC at protein replacement levels of 0, 25, 50, 75 and 100% were offered by hand twice daily. Growth rates of fish fed diets with zero and 25% replacement were not significantly different, with SGRs of 2.47 and 2.28, respectively. At higher replacement levels, growth rates decreased significantly with SGRs of 2.00, 1.33 and 0.68, respectively. Feed conversion ratios increased with soya replacement, with values of 0.68, 0.75, 0.89, 1.27 and 2.32, respectively, although there was no significant difference between the first two. Feed consumption rates remained constant up to 50% replacement, above which they decreased significantly, possibly because of reduced diet palatability. Apparent protein digestibility (APD) was not affected by the incorporation of SPC and ranged from 82.8 to 87.5%. Results suggest that protein catabolism increases in SPC-rich diets, possibly because of rapid assimilation and utilization of the methionine supplement. In the second experiment, the importance of amino acid supplements and the beneficial effects of protecting these, either by coating them in protein or incorporating them in a protein,lipid emulsion, was investigated. Growth data provided some indication that the utilization of SPC may be improved by incorporating the methionine and lysine supplement in a protein,lipid emulsion prior to diet preparation, although this finding was not found to be statistically significant (0.1 < P < 0.2). [source]


Evaluation of fermented fish-offal in the formulated diet of the freshwater catfish Heteropneustes fossilis

AQUACULTURE RESEARCH, Issue 13 2008
Kausik Mondal
Abstract A 60-day feeding trial was conducted to test the effect of partial replacement of fishmeal by fish-offal (FO) in the diet for the freshwater catfish Heteropneustes fossilis. Three isonitrogenous (31.4% CP) diets were formulated to include a reference diet (T1) with 40% fishmeal (FM) and 0% FO and two supplementary diets: one (T2) containing 25% FM and 25% FO and another (T3) containing 20% FM and 30% FO. The FO was fermented along with mustard oil cake and rice bran before using it as an ingredient in the preparation of feed. Two separate trials were conducted with these three diets: a growth trial and a digestibility trial. H. fossilis fed the diets containing FO showed better growth and proximate composition of carcass than those fed the reference diet. Fish fed T3 diet showed maximum feed conversion, protein utilization and growth. Apparent protein digestibility (APD) was also significantly higher in the T3 diet as compared with the T1 diet. The results of the trial indicated that using microbial fermentation, FO could be included up to a 30% level as a partial (50%) replacement of fishmeal in the formulation of diet for H. fossilis. [source]


Influence of insoluble dietary cellulose on digestive enzyme activity, feed digestibility and survival in the red claw crayfish, Cherax quadricarinatus (von Martens)

AQUACULTURE RESEARCH, Issue 1 2006
Ana Pavasovic
Abstract Red claw (Cherax quadricarinatus) is a freshwater crayfish species with recognized potential for aquaculture. To better understand the digestive processes and nutritional requirements of red claw, we have examined the effects of dietary cellulose on (1) digestive enzyme activity and diet digestibility and (2) survival rate, feed conversion ratio and growth performance. In the first study, a reference diet (RF) and test diets consisting of 70% RF and 30%,-cellulose or Fuller's earth were prepared. Analysis of digestive enzyme profiles revealed that amylase and cellulase activities in midgut gland (MG) extracts were highest in the red claw fed on a diet containing 30% Fuller's earth and lowest in those fed on a diet containing 30%,-cellulose. Supplementation of the RF diet with either 30%,-cellulose or Fuller's earth significantly reduced apparent dry mater (ADMD) and apparent protein digestibilities (APD). In the second study, a feeding trial was conducted using diets supplemented with different levels of ,-cellulose. A major finding was that dietary cellulose levels above 12% were correlated with significant reductions in survival rate, specific growth rate and feeding efficiency. Based on these findings, we suggest that although cellulase enzymes are present in the red claw digestive system there are no apparent nutritive benefits obtained by including insoluble cellulose in diets for this species. [source]


Nutritional evaluation of various plant protein sources in diets for Asian sea bass Lates calcarifer

JOURNAL OF APPLIED ICHTHYOLOGY, Issue 2 2000
By P. S. Eusebio
A biological assay was conducted to evaluate the suitability of various leguminous seed meals and leaf meals as dietary protein sources for Asian sea bass, Lates calcarifer. In the growth experiment, fish (initial mean weight ▒,standard error (SE) of 3.8 ▒ 0.5 g) were fed isonitrogenous and isocaloric diets containing test ingredients to replace 13,18% of the diet. The same diet formulations were used in a digestibility experiment, except that 1% Cr2O3 was added as an external indicator. The growth of the control fish was comparable to fish fed leguminous seed meal-based diets, and better than those given leaf meal-based diets. The control diet had the highest apparent protein digestibility (APD) value. No significant differences were observed between the APD of white cowpea (Vigna unguiculata), green mungbean (V. radiata) and papaya (Carica papaya) leaf meal-based diets. However, the cassava (Manihot esculenta) leaf meal-based diet had the lowest APD value. The present findings suggest that white cowpea and green mungbean meals can be used as protein sources in practical diets to replace 18% of the sea bass diet without affecting their growth. [source]


Evaluation of In Vitro Apparent Protein Digestibility by Shrimp Using Gut Enzyme Extracts

JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2009
Joe M Fox
Knowledge of apparent protein digestibility (APD) is required for optimization of feed formulae for the production of marine penaeid shrimp. The purpose of this study was to evaluate an in vitro method for determining APD in marine penaeid shrimp using gut enzyme extracts. A high correlation (r2 = 0.95) was shown between single-ingredient APD values for fish meal diets using in vivo methodology and those derived from in vitro testing of ingredients. A second study showed positive correlation (r2 = 0.71) between in vitro APD of selected purified and semipurified ingredients and their reported in vivo APDs. This correlation was much higher for purified ingredients (r2 = 0.93) versus less-refined ingredients (r2 = 0.24). A third trial compared in vitro APD at three different enzyme extract pH values and showed that for most protein sources, APD was significantly highest (P < 0.05) at pH = 7.0 and lower at pH = 6.1 or 7.9, indicating a neutral pH optimum for this methodology. [source]


Amino acid availability and protein digestibility of several protein sources for Nile tilapia, Oreochromis niloticus

AQUACULTURE NUTRITION, Issue 5 2008
I.G. GUIMAR├ES
Abstract Apparent amino acid availability coefficients and protein digestibility of four animal products [fish meal (FM), meat and bone meal (MBM), poultry by-product and feather meal] and four plant protein-rich products [soybean meal (SBM), cottonseed meal-28, cottonseed meal-38 and corn gluten meal (CGM)] were determined for Nile tilapia, Oreochromis niloticus. Ingredients were incorporated to a practical reference diet at a 7 : 3 ratio (70% of reference diet and 30% of test ingredient). Chromic oxide was used as external digestibility marker. Among animal products poultry by-product meal (PBM; 89.7%) and FM (88.6%) presented the highest apparent protein digestibility (APD) while MBM (78.4%) and feather meal (78.5%) presented the lowest APD. Among plant protein-rich products CGM (91.4%) and SBM (92.4%) presented the highest APD values while cottonseed meal-28 presented the lowest APD (78.6%). Average apparent amino acid availability of feed ingredients was similar to protein digestibility with 92.3%, 89.6%, 73.4%, 80.7%, 88.9%, 84.4%, 91.2% and 79.7% values for SBM, CGM, cottonseed meal-28 and 38, FM, MBM, PBM and feather meal respectively. These results indicate that O. niloticus is able to utilize efficiently different feedstuffs. [source]


Nutritional value of feed peas (Pisum sativum) in practical diet formulations for Litopenaeus vannamei

AQUACULTURE NUTRITION, Issue 2 2002
D.A. DAVIS
Dry peas of mixed Canadian prairie varieties which were commercially obtained and processed to provide a variety of meals were evaluated in practical shrimp feeds. Whole and de-hulled peas were pin milled to produce raw flours. A portion of these meals were processed to produce whole extruded and de-hulled extruded meals. Additionally, a portion of the whole pea meal was processed by infrared cooking to produce a micronized meal. The five meals were evaluated in practical diets for Litopenaeus vannamei under controlled laboratory conditions. The first experiment was designed to estimate apparent protein and energy availability of the various meals. Using a practical reference diet, the meals were substituted using a 70:30 ratio to produce the test diets. Based on contrasts, both extruding and micronizing the pea meals resulted in significant improvements in both apparent protein digestibility and apparent energy digestibility values. Apparent energy digestibility values for the various ingredients expressed as percentage ▒ SD were: whole raw, 72.3 ▒ 8.1; whole extruded, 86.0 ▒ 8.9; de-hulled raw, 88.4 ▒ 4.4; de-hulled extruded, 94.4 ▒ 10.0; whole micronized, 94.1 ▒ 10.2. To evaluate the response of shrimp to the diets containing pea meal, two 7-week growth trials were conducted in the laboratory using a practical diet formulated to contain 360 g kg,1 protein and 90 g kg,1 lipid. In the first growth trial the shrimp had a mean initial weight of 0.66 g and six test diets were evaluated that included the basal diet and five diets for which the pea meals were included in the diet at 250 g kg,1 dry weight replacing whole wheat. In the second growth trial the shrimp had a mean initial weight of 1.1 g and only the whole raw and whole extruded meals were evaluated at 50, 100 and 200 g kg,1 inclusion in the diet. At the conclusion of the first growth trial weight gain ranged from 718 to 862% and at the conclusion of the second growth trial weight gain ranged from 394 to 502%, with no significant differences or discernible trends observed as a result of the various dietary treatments. Based on the observed results, the continued evaluation of feed peas as a potential ingredient of shrimp feeds is warranted. Additionally, if feed peas are suitably priced, commercial producers are encouraged to evaluate feed peas as an alternative protein and energy source. [source]


Evaluation of an in vitro digestibility technique for the prediction of protein digestibility in the South African abalone, Haliotis midae L.

AQUACULTURE NUTRITION, Issue 1 2002
T.A. SHIPTON
A pH-stat multienzyme in vitro digestibility assay was investigated for its efficacy in predicting apparent protein digestibility coefficients in abalone diets. Linear regression analysis between in vitro digestibility estimates and in vivo digestibility coefficients obtained from abalone, revealed that the technique could be used to reliably predict apparent protein digestibility. Maximal predictability of the system was obtained when protein sources were analysed according to origin , animal or plant. The technique was used to assess the apparent protein digestibility of 34 potential protein sources for use in formulated feeds for Haliotis midae. [source]


Replacement of fish meal with a mixture of different plant protein sources in juvenile Nile tilapia, Oreochromis niloticus (L.) diets

AQUACULTURE RESEARCH, Issue 13 2003
Deyab M S D El-Saidy
Abstract A plant protein mixture (PPM) was tested to replace fish meal (FM) in diets for juvenile Nile tilapia, Oreochromis niloticus. Fish averaging (▒SD) 3.7▒0.14 g were divided into 15 groups. Three groups were fed each of five isonitrogenous (33.6%) and isocaloric (4.7 kcal g,1) diets replacing 0%, 25%, 50%, 75% and 100% of the FM protein with similar percentages of PPM (PPM0, PPM25, PPM50, PPM75 or PPM100 respectively). The PPM consisted of 25% soybean meal, 25% cottonseed meal, 25% sunflower meal and 25% linseed meal, and 0.5% of both methionine and lysine were added to each diet except for the control. After 16 weeks of feeding, the fish fed diets PPM75 and PPM100 exhibited growth performance not differing significantly from the fish fed control diet. PPM substitution of up to 75% of the FM protein did not result in differences in the apparent protein digestibility compared with the control, whereas in the PPM100 group digestibility was significantly lower than in the other groups, except for fish fed the PPM75 diet. The incorporation of PPM in diets did not significantly affect whole-body dry matter, protein, fat or energy compared with the control. The cost,benefit analyses of the test diets indicated that the PPM diets were economically superior to FM. The protein from PPM can completely replace the FM protein in the diets for Nile tilapia, based on the results of this study. [source]