Differences In Apparent Digestibility Coefficients Research Articles

Effects of alcohol extract from defatted soybean meal on bile acid level, digestive enzyme activity and nutrient digestibility of pompano <i>(Trachinotus blochii)</i>

Defatted soybean meal (SBM), which is produced by defatting soybean with solvents, has been considered as the most cost-effective substitute for fish meal (FM) in fish diets. However, SBM contains alcohol-soluble components which may interfere with growth performance and digestive physiology of fish. This study examined the effects of alcohol extract (Ext) containing alcohol-soluble components extracted from SBM on bile acid level, digestive enzyme activity and nutrient digestibility of pompano Trachinotus blochii. SBM was processed and separated into Ext and ethanol-extracted SBM (ESBM), thus, ESBM was SBM without alcohol-soluble components. Four experimental diets were formulated, denoted as FMD (FM-based diet), SBMD (SBM-based diet), ESBMD (ESBM-based diet), and ESBM+ExtD (ESBM-based diet plus Ext). Each diet was fed to two groups of fish (20 fish/group, 25 g/fish) for 4 weeks. Results showed that plasma lipid components, anterior intestinal bile acid level, anterior intestinal trypsin and lipase activities, and protein and lipid apparent digestibility coefficients (ADCs) of SBMD -fed fish were similar to those of ESBM+ExtD-fed fish. These parameters were significantly lower in SBMD-fed and ESBM+ExtD-fed fish than in ESBMD-fed and FMD-fed fish (P < 0.05). There were no significant differences in plasma total cholesterol level, trypsin activity, and protein ADC between ESBMD and FMD groups, however, total bile acid level, lipase activity, and lipid ADC were significantly lower in ESBMD -fed fish than fish fed FMD (P < 0.05). These results indicated that alcohol extract containing alcohol-soluble components extracted from SBM inhibited the secretions of bile acids and pancreatic digestive enzymes in pompano fish, and these abnormalities might impair nutrient digestion and absorption. The findings of the present study suggested that removing alcohol extract and supplementation of taurine could be effective for improving nutritional quality of SBM and enhancing feed utilization and growth performance of pompano which were fed SBM-based diets.

Protein digestive dynamics of meat and bone meals in broiler chickens

This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals (MBM). A total of 252 male Ross 308 broiler chickens were offered 7 atypical diets largely based on maize and MBM from 24 to 28 d post-hatch. Each experimental diet was offered to 6 replicates with 6 birds per replicate cage. Excreta were collected in their entirety from 25 to 27 d post-hatch and on 28 d post-hatch. Digesta samples were collected from the proximal jejunum, distal jejunum, proximal ileum and distal ileum. Apparent digestibilities of protein were determined in each segment and apparent digestibilities of amino acids were measured in the distal ileum. There were significant differences in apparent protein digestibility coefficients in the proximal jejunum (P = 0.006), where broiler chickens offered the high ash beef meal (diet 7) generated the lowest protein digestibility in the proximal jejunum (0.318). Similarly, there were significant differences in apparent digestibility coefficients in the distal jejunum (P < 0.001) and distal ileum (P < 0.001) but not in the proximal ileum. More pronounced differences were found in the disappearance rate of protein and there were significant differences in all 4 segments of the small intestine (P < 0.001). Broiler chickens offered the high ash beef meal had the lowest protein disappearance rate (P < 0.001). No difference was observed in the predicted protein digestion rate (P = 0.486) but chickens offered the high ash beef meal had the lowest potential digestible protein (0.662, P = 0.034) whereas the highest potential digestible protein (0.739) was detected in diet 5 (containing a beef meal). This study contributed to the establishment of a preliminary database to include digestion rates of starch and protein into practical diet formulation.

Screening of nutrient digestibility, glycaemic response and gut morphology alterations in gilthead seabream (Sparus aurata) fed whole cereal meals

The effects of whole cereal meals on growth, nutrient digestibility, glycaemic response and gut morphology were studied in gilthead seabream juveniles. Groups of 30 fishes (in triplicate) were fed four isoproteic (47%) and isolipidic (16%) diets including 30% of wheat, corn, barley or rye meals. Growth performance was higher in fish fed the wheat diet than the rye diet. Feed efficiency and protein efficiency ratio were higher with the wheat and barley diets than in the other groups. There were no differences in apparent digestibility coefficients (ADCs) of dry matter, protein or lipids among diets. However, ADC of corn and barley starch was lower than that of wheat and rye starch. Average plasma glucose levels were lower in fish fed the barley diet. Plasma glucose peaked 10h after feeding in all groups except the corn group which peaked 8h after feeding. Shorter hyperglycaemia duration was observed in fish fed the corn diet (12h) than the other diets (>12h). Gut morphology was similar in all groups irrespective of the sampling point. Based on growth performance, feed utilization efficiency, ADC of starch and glycaemic response we can conclude that wheat and barley are more efficiently used than corn or rye by gilthead seabream juveniles and thus are the preferential cereal sources to be used as plant feedstuffs in diets for this species. Statement of relevanceEffective growth of fish at reduced costs.

Partial or total replacement of fish meal by local agricultural by-products in diets of juvenile African catfish (Clarias gariepinus): growth performance, feed efficiency and digestibility

The study was undertaken to evaluate the growth performance and feed utilization of African catfish, Clarias gariepinus, fed six diets (D) in which fishmeal (FM) was gradually replaced by a mixture of local plant by-products. In diets 1 and 2, FM (250 g kg-1) was replaced by sunflower oil cake (SFOC). In diets 3 and 4, FM (250 and 150 g kg-1, respectively) was replaced by SFOC and bean meal (BM) while FM was totally substituted by a mixture of groundnut oil cake (GOC), BM and SFOC in diets 5 and 6. Sunflower oil cake was cooked, soaked or dehulled in order to determine the appropriate processing techniques for improving the SFOC nutritive value and to evaluate the apparent digestibility coefficient (ADC) values of the alternative diets. No significant differences were observed for daily feed intake, weight gain, specific growth rate (SGR) and feed efficiency (FE) among fish fed D1, D2, D3 (250 g kg-1 FM), D4 (150 g kg-1 FM) and D6 (0 g kg-1 FM). The highest SGR (3.2% per day) and FE (1.2) were achieved in fish fed D3, and the lowest in fish fed D5 (0% FM), suggesting a maximum acceptable dietary concentration of hulled SFOC below 250 g kg-1 in African catfish juveniles. Protein efficiency ratio ranged from 2.2 to 3.2 for all dietary treatments and was positively influenced by FM inclusion. African catfish were able to digest plant protein very efficiently in all diets tested. ADC of protein ranged from 88.6 to 89.5%, while ADC of energy was relatively low for diets containing hulled sunflower oilcake (71-74%) and high when sunflower oilcake was dehulled (78.6-81.3%). Similarly, ADC of dry matter was higher when sunflower was dehulled (72.1%) when compared with crude SFOC (60.5%). Soaking increased ADC values for neutral detergent fibre (NDF), dry matter, energy, protein and amino acids (AA). There were no significant differences in protein ADCs (88-90%) with increased levels of dietary vegetable ingredients. Both soaking and dehulling of sunflower before incorporation helped in the reduction of NDF, antitrypsin and tannins. Digestibility of all AA was generally high, greater than 90% for both indispensable and non-indispensable AA. Based on the data obtained, it was possible to totally replace menhaden fish meal with a mixture of vegetable proteins (72% of total dietary protein) when diets contained a relatively low percentage of animal protein (28% based on blood meal and chicken viscera meal) without negative effects.

Comparison of apparent digestibility coefficient among replicates and different stocking density in red sea bream Pagrus major

Two consecutive feeding trials were conducted to know: (i) how the apparent digestibility coefficient (ADC) varies among replicates on different days and during the course of the experiment (Trial 1); and (ii) the effect of stocking density (e.g. 7.17, 5.56, and 3.92 kg fish/t water) on the ADC of nutrients and energy in red sea bream (Trial 2). In both trials, 0.5% Cr2O3 was used as an inert marker. In Trial 1, there were no significant differences in ADC within the replicates although the values on different days varied significantly during the second week. The ADC of all parameters in the third and fourth weeks was significantly higher than in the second week (P<0.05). Although statistically insignificant, the lower stocking densities (3.92 and 5.56 kg fish/t water) showed better growth performance and superior ADC of protein, lipid, and energy than the higher stocking density in Trial 2. The results indicated that it may be better to acclimate fish to the diet for at least three weeks to obtain more reliable data by using a single tank for each treatment for digestibility experiments. Results also indicated that growth and digestibility performance can be stimulated by controlling stocking density.

Comparison of faecal collection method with high- and low-quality diets regarding digestibility and faeces characteristics measurements in Nile tilapia

The need for unbiased digestibility estimation has led to the development of a number of faeces collection methods. However, there is still a large variation in apparent digestibility coefficient (ADC) of diet/ingredients between these methods. This study investigated the impact of dietary quality on ADC and faeces recovery measurements obtained by two faecal collection methods (Choubert and settling tank). The fish were fed five diets: a control diet as high-quality diet, two levels of dried duckweed (20% and 40%) and two levels of fresh duckweed (20% and 40%), which were added to the control diet, as low-quality diets. Apparent digestibility coefficient estimates were highly correlated (r>0.95) between both faecal collection methods. For all diets the ADC estimates were higher when using settling tanks compared with Choubert collectors. For the control diet differences in ADC between two collectors were small, but by inclusion of duckweed these differences increased. The recovery percentage of faeces was not correlated between both faecal collection methods (r=0.22, P=0.41). The estimated recovery percentage of faeces by settling tanks was about three times higher than by Choubert. In conclusion, the differences in ADC and faeces recovery measured by two faecal collection methods depend on diet quality

A study on the meat and bone meal and poultry by-product meal as protein substitutes of fish meal in practical diets for Litopenaeus vannamei juveniles

A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fish meal in the diets on the growth performance, survival and apparent digestibility coefficients (ADC) of Litopenaeus vannamei. The basal diets were formulated with 22% fish meal and other ingredients which provided about 40% protein and 9% lipid in the diet. The experimental diets included MBM or PBM to replace 0, 20%, 40%, 60% and 80% of total fish meal respectively. All diets were iso-nitrogenous and isocaloric in gross terms. The results showed that there were no significant differences (Pτ;0.05) in growth performance and ADC among the treatments fed with the diets in which 0–60% fish meal had been replaced with MBM, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decreased when the MBM was up to 80% of the fish meal. There were no significant differences (Pτ;0.05) in growth performance and ADC among all the treatments fed with the diets in which 0–80% fish meal had been replaced with PBM.

Apparent Digestibility Coefficients of Nutrients and Nutritional Value of Poultry By‐product Meals for Rainbow Trout Oncorhynchus mykiss Measured in vivo Using Settlement

AbstractFish meal production is not growing worldwide, therefore, it is important to search for alternative protein sources. Three types of poultry by‐product meals (feed grade, prime, and refined) and two fish meals (herring and menhaden) were mixed into a casein‐gelatin purified reference diet at 30% to measure apparent digestibility coefficients (ADCs) for rainbow trout Oncorhynchus mykiss. A total of 90 fish (initial mean body weight 294.6 ± 10.7 g) were stocked into six 140‐L fiberglass digestibility tanks at 15 fish per tank. Individual tanks were assigned randomly to each of the five experimental diets and the reference diet. Fecal collection by settlement lasted for 2 wk. Feces collected in each week represented a replicate, and they were analyzed separately. The ADCs of nutrients for herring meal, menhaden meal, feed grade poultry by‐product meal, prime poultry by‐product meal, and refined poultry by‐product meal were: dry matter, 81.3, 70.9, 70.9, 71.5, and 74.5%, respectively (P= 0.0168); crude protein, 89.8, 85.8, 83.1, 84.8, and 87.1%, respectively (P= 0.0032); crude fat, 91.5, 90.7, 79.7, 82.7, and 79.9%, respectively (P= 0.0004); ash, 76.6, 66.2, 74.1, 77.4, and 79.6%, respectively (P = 0.2880); phosphorus, 58.2, 46.9, 49.4, 45.8, and 56.0%, respectively (P = 0.0143); gross energy, 88.2, 84.0, 81.9, 83.4, and 79.8%, respectively (P= 0.2466). Significant differences in ADCs of essential amino acid existed only for arginine, leucine, and tryptophan when comparing refined poultry by‐product meal with herring meal. Results showed that refined poultry by‐product meal had similar ADC values to herring meal, thus, it has a similar nutritional value and can replace portions of herring meal in rainbow trout feeds. Furthermore, differences exist in ADC values among grades of poultry by‐product meals that should dictate appropriate use levels in rainbow trout feeds.

Nutritional assessment of protein from beans (Phaseolus vulgaris L) processed at different pH values, in growing rats

AbstractThe effect of the commonly used processing techniques of soaking (at different pH values) and cooking on the digestive and metabolic utilisation of protein from common beans (Phaseolus vulgaris L) in growing rats was studied. Before the cooking step, beans were soaked in solutions of pH 2.6, 5.3 or 8.4. Analyses of beans soaked at moderately acid pH (5.3) showed a significant increase in essential amino acids, especially cysteine. Food intake and growth indices were also dependent on pH. All indices were better in animals fed with beans soaked in a basic pH solution than when an acid soaking solution was used. In contrast with the findings expected on the basis of the chemical analysis of protein composition of the food, the worst results for food intake and growth were found in rats fed with beans soaked at pH 5.3. There were no significant differences in apparent digestibility coefficient between different groups of animals. The highest metabolic utilisation of protein (balance) was found in animals fed with beans soaked in a basic solution; however, the values were insufficient to account for the faster rate of growth in this group. The better growth rate was probably due to the improved utilisation of carbohydrates in beans soaked in the basic pH (8.4) solution.© 2001 Society of Chemical Industry

Replacement of fish meal in diets for Australian silver perch, Bidyanus bidyanus: I. Digestibility of alternative ingredients

Apparent digestibility coefficients (ADCs) for dry matter, nitrogen, energy and individual amino acids for 29 commonly used feed ingredients were determined for silver perch, a native Australian freshwater species currently being cultured in Australia, Taiwan and China. ADCs were determined using faeces collected following settlement. Results from 11 experiments are reported. Each experiment included a reference diet and test diets, which were composed of 69.3% reference diet, 29.7% test ingredient and 1% chromic oxide (inert indicator). Ingredients tested included Australian, Danish and Peruvian fish meals, blood meal, meat and bone meals from beef and lamb, poultry meal, feather meal, soybean and canola meals (both expeller and solvent extracted for each), full fat soybeans, peanut meal, cottonseed meal, linola, two species of lupins, field peas, faba beans, chick peas, vetch, cow peas, wheat gluten, corn gluten meal, two cultivars of wheat, millrun and sorghum. ADCs for dry matter, energy and nitrogen were highest for fish meal, although several other ingredients, including some animal meals and gluten from wheat and corn, had similar ADCs for dry matter and energy. Digestible protein from these ingredients was in the range 52–86% compared with 63–69% for fish meals. Silver perch were capable of digesting protein very effectively in almost all ingredients tested. Amino acid availability reflected nitrogen digestibility except for Peruvian fish meal and the two meat and bone meals, for which the availability of some amino acids was lower, possibly indicating protein damage during processing. Oilseeds and legumes also tended to have lower ADCs for some amino acids (e.g., sulphur amino acids) than for other amino acids. Differences in ADCs for nitrogen and individual amino acids indicate the need for individual amino acid availability data. The data provided a useful starting point for least-cost formulation of diets for silver perch.

Digestibility of diets with precooked rye or wheat by Atlantic salmon, Salmo salar , L.

Abstract Four extruded diets, differing in grain supplementation, were fedto triplicate groups of Atlantic salmon (Salmo salar, L.) with amean weight of 0.5 kg in a digestibility trial. The diets contained100 or 150 g kg –1 of precooked rye or wheat, replacing fish meal.There were no significant differences in apparent digestibilitycoefficients (ADC) of protein, fat or starch which could berelated to dietary carbohydrate source or inclusion level. TheADC of dry matter and energy were higher for the diets withwheat than for those with rye, and higher for the diets with 100 gprecooked grain kg –1 than for those with 150 g kg –1 . The meanADC of starch was 52% for rye, and 53% for wheat. KEY WORDS : Atlantic salmon, digestibility, starch, rye, Salmosalar, wheat Received 29, July 1997, accepted 14 November 1997Correspondence: Dr T. Storebakken, Institute of Aquaculture Research, AS. (AKVAFORSK), N-6600 Sunndalsora, Norway (e-mail:trond.storebakken@akvaforsk.nlh.no) Introduction Cereal grains are used in extruded fish feeds to facilitate bindingand expansion. The starch is also a source of glucose and energyfor the fish. The objective of this experiment was to find out iftwo different precooked grains, rye and wheat, affecteddigestibility of macronutrients in a different manner whenincluded in extruded diets for Atlantic salmon Salmo salar.The ability of salmonids to hydrolyse native wheat starch islimited, but is considerably improved by heat treatment and gela-tinization of the starch, as shown in rainbow trout Oncorhynchusmykiss by Henrichfreise & Pfeffer (1992). Although efficienthydrolysis of precooked starch can be obtained by Atlanticsalmon with low dietary inclusion levels, the digestibilitydecreases with increasing dietary concentration (Aksnes 1995)and appears to be limited when the dietary concentration exceeds90 g kg

Bioavailability of all- E-astaxanthin and Z-isomers of astaxanthin in rainbow trout ( Oncorhynchus mykiss)

Two cold-pelleted diets containing either 36.9 or 35.4 mg kg −1 of predominantly all- E-astaxanthin (97% of total astaxanthin) or a mixture of all- E- and Z-astaxanthin (64 and 36%, respectively), were fed to duplicate groups of rainbow trout ( Oncorhynchus mykiss) in freshwater (initial weight 0.4 kg) for 69 days. Average final weight was ca. 1.0 kg for both groups and the specific growth rate was 1.2–1.3% d −1. The all- E- and Z-isomer mixture of astaxanthin was produced from Carophyll Pink ® by an iodine-catalyzed isomerization. Flesh astaxanthin concentrations increased from 1.7 mg kg −1 in the initial sample to 6–7 mg kg −1 after 31 days. After 69 days, flesh carotenoid concentration of the trout fed all- E-astaxanthin tended to be higher than in trout fed the astaxanthin stereoisomer mixture (10.0 and 8.6 mg kg −1, respectively). At the end of the experiment, the trout fed all- E-astaxanthin had significantly redder (through the color tristimuli analysis CIE [1976], a ∗ tristimuli value) flesh than rainbow trout fed a mixture of all- E- and Z-astaxanthin. Apparent digestibility coefficients (ADC) of total astaxanthin were significantly higher in trout fed all- E-astaxanthin (79%) compared to trout fed the stereoisomer mixture (64%). No significant differences in the ADC of all- E-astaxanthin was observed between the two treatments, indicating a competitive mechanism of uptake of the different stereoisomers. ADC of all- E-astaxanthin was higher than that of 9 Z- and 13 Z-astaxanthin, and the ADC of 13 Z-astaxanthin was significantly higher than that for 9 Z-astaxanthin. This indicates that the Z-astaxanthin isomers are not utilized to the same extent as all- E-astaxanthin for flesh pigmentation. No significant differences were observed in total astaxanthin retention in the flesh. However, the retention of all- E-astaxanthin was higher in trout fed the stereoisomer mixture of astaxanthin than in the group fed all- E-astaxanthin. The better utilization of digestible carotenoids in the trout fed a mixture of all- E- and Z-astaxanthin isomers did not fully compensate for the low digestibility of astaxanthin in this group. No differences in astaxanthin stereoisomer composition in the flesh were observed between treatments. This indicates a selectivity in metabolism of the different stereoisomers of astaxanthin, either during absorption, transport or deposition, or their combinations and suggests that substantial isomerization of astaxanthin Z-isomers occurs in the liver. The retention of dietary astaxanthin in the flesh was as high as 24–32%. No significant differences in ADC were observed for dry matter, protein, fat or energy, while ADC for ash was significantly higher for the group fed the diet containing all- E-astaxanthin. The tendency for higher retention of digestible total astaxanthin in the flesh of trout fed a stereoisomer mixture of astaxanthin suggests that the stereoisomer composition of the dietary astaxanthin may influence the absorption capacity and bioavailability of total astaxanthin, probably by increasing intestinal micellar load of total astaxanthin.