Apparent Digestibility Coefficients of Nutrients in Diets Containing Jatropha curcas seedmeal by Oreochromis niloticus

This study evaluated the effect of supplementation of a plant ingredients-based diet with two levels of commercially digestive enzyme products: Synergen™ and Natugrain® on the apparent digestibility coefficients (ADCs) of nutrients and on digestive enzyme activities in European seabass (Dicentrarchus labrax) juveniles. A control diet was formulated with 450 g/kg CP (200 g/kg from fish meal + 800 g/kg from plant protein) and 180 g/kg CL (fish oil), and four other diets were made similar to the control but supplemented with 0.2 g/kg or 0.4 g/kg of Synergen™ and Natugrain®. Digestive enzyme activities were not affected by dietary treatments. Nevertheless, chyme pH along the intestine of fish fed the Natugrain®-supplemented diets was reduced. The ADC of nutrients increased with exogenous digestive enzyme supplementation, with the highest ADC values being observed for the 0.4 g/kg Natugrain® diet. The ADC of dry matter, protein, lipids, energy and phosphorus in this diet were 26%, 6%, 4%, 16% and 63% higher, respectively, than in the control diet. Overall, diet supplementation with exogenous enzyme complexes seems to have high potential for improving the utilization of plant feedstuff-rich diets for seabass juveniles. This study revealed that Natugrain® was more effective than Synergen™ in improving the ADC of nutrients and energy in European seabass juveniles.

The growth performance and apparent nutrient digestibility co – efficients of weaned rabbits fed corn – soybean meal basal diets containing different forms of cocoa pod husk meal were determined. A total of 60 mixed breed rabbits of both sexes (30 bucks and 30 does) with average initial weight of 606.42±1.30g were used in a nine week feeding trial using a completely randomized design. Twelve is nitrogenous and is caloric diets were formulated containing sundried (T1 T2, T3 & T4), fermented (T5 T6, T7 & T8), and hot - water treated (T9 T10, T11 & T12) cocoa pod husk meal (CPHM) each at 0, 12.5, 25 and 37.5% levels of inclusion, respectively. Diet with 0% CPHM served as the control in the different forms of the cocoa pod husk meal based diets. Growth performance parameters (feed intake, weight gain and feed conversion ratio) were determined, while apparent nutrient digestibility coefficients were determined at the 9th week using the direct in vivo method. The digestibility co - efficients were calculated using appropriate formula. Results of the study revealed that the final weight, total weight gain and average daily feed intake recorded significant (P<0.05) differences between dietary treatments. When compared with values in the control, diets with the highest inclusion level (37.5%) CPHM had the least total weight gain with the sundried, fermented and hot – water treated groups having 557.50, 570.83 and 390.00 g/rabbit respectively. The average daily feed intake declined with increasing levels of sundried CPHM (i.e. 66.94, 62.56, 59.27 and 52.98 g/rabbit/day, respectively). The hot – water treated CPHM diets recorded the worst FCR beyond 12.5% level when compared with other forms of CPHM. Some of the apparent nutrient digestibility coefficients for ash and NFE recorded significant (P<0.05) differences between dietary treatments, while crude protein, crude fibre and ether extract digestibility coefficients were statistically similar across dietary treatments in all the three forms of CPHM. The sundried CPHM had the least digestible crude protein (75.07%) at the highest inclusion level (37.5%). The study concludes that the three different forms of cocoa pod husk meal in the following order of superiority (fermented, hot – water treated and sundried) can be included in diets meant for rabbits at levels not exceeding 25% for optimum growth performance and apparent nutrient digestibility co - efficients.

Response of common carp fry fed diets containing a pea seed meal ( Pisum sativum) subjected to different thermal processing methods

Apparent digestibility coefficients (ADC) of nutrients and individual amino acids (AA) for 13 feed ingredients as affected by feeding level were determined for African catfish, a species of economic importance in Africa. Results from two trials are reported. In each trial, ADC were determined using a reference diet and test diets with yttrium oxide as indicator. Juvenile African catfish (averaging 53.9 g, trial 1; 40.4 g, trial 2) were stocked in tanks connected to a common recirculation aquaculture system. Ingredients tested included hydrolysed feather meal (HFM), fishmeal (FM), insect meal (IM), soybean meal (SBM), sunflower meal (SFM), poultry meal (PM), corn dried distillers grains with solubles (CDDGS), faba beans (FB), lupine meal (LM), pea protein (PP), guar meal (GM), canola meal (CM) and yeast meal (YM). The effect of feeding level on ADC was determined by feeding fish restrictively (80% satiation) for 5 weeks and subsequently to apparent satiation for 2 weeks. Inclusion of yeast meal at 30% resulted in low palatability. ADC of nutrients were significantly affected by feeding level (except for fat and carbohydrate), but the effect was ingredient-dependent. African catfish was able to digest protein very effectively in almost all tested ingredients with ADC values ranging from 85.6 to 105.1% across feeding periods. Several ingredients tested, including animal protein ingredients and YM had similar high ADC for dry matter as FM. However, the ADC of AA differ among ingredients, indicating a need for digestible amino acid profile data. Methionine (Met) was the first limiting essential amino acid in HFM, FB, and LM with values ranging from 5−6 g/kg, expressed as digestible Met (dMet) per unit of digestible protein (DP), compared to FM (27 g dMet/kg DP). IM had comparable and sometimes higher overall digestible essential AA values compared to FM, except for methionine and lysine. For oilseeds and legumes, SBM tended to be the best quality AA source, as it had the highest digestible essential amino acid profile. These data provide information concerning nutrient and digestible AA values, which will allow a more efficient use of alternative ingredients in African catfish diets. Formulating diets based on the digestible AA in ingredients will aid precise feed formulation, thereby minimising economic losses and reducing the environmental footprint of aquaculture production.

Apparent digestibility coefficients of energy and nutrients of some ingredients for Nile tilapia, Oreochromis niloticus (L.) (Thai strain). Digestible energy and apparent digestibility coefficients of nutrients were determined for some ingredients fed to the Nile tilapia (25.4 ± 3.88 g). Fish were fed on pelletized diet to apparent satiation and the digestibility value of each ingredient was determined by comparison of digestibility of a reference diet (33% crude protein and 0.1% chromic oxide). Digestible energy values were 3607.47; 2701.24; 3114.54 and 4008.95 kcal/kg for corn, wheat meal, soybean meal and fish meal, respectively. The apparent digestibility coefficients were 87.12; 78.21; 92.72 and 84.95% for protein, 94.4; 87.12; 78.21; 92.72; and 84.95% for ether extract, 87.27; 79.5; 76.15; 85.04 and 90.62% for calcium and 61.15; 45.08; 29.51; 47.14 and 49.78% for phosphorus, corn, wheat meal, soybean meal and fish meal, respectively. Results indicated that foodstuffs rich in carbohydrates are effectively utilized by the Nile tilapia.

Two experiments were conducted to measure the apparent digestibility coefficients (ADCs) of nutrients, dry matter, and energy in by-products of the brewing industry and in selected animal protein ingredients for rainbow trout. In experiment 1, 500 rainbow trout (average body weight 170.8±5.5 g) were stocked in ten 140-L digestibility tanks with 50 fish per tank and two tanks per diet. Yttrium oxide was used as an inert marker in the diets. The high fibre content of brewer's dried grains (BDG) affected the ADCs of dry matter but not of protein or amino acids. Brewer's dried yeast had a higher protein content than BDG, but ADC values for protein and amino acids were significantly lower. The ADCs of phosphorus were similar among brewer's dried products. The BDG high-protein, fraction had marginally higher ADC values for dry matter, protein and amino acids than regular BDG. Conditions in experiment 2 were similar to those in experiment 1. ADC values for spray-dried porcine plasma were over 98% for dry matter, crude protein, crude fat, and gross energy. ADC values for spent hen meal were higher than those of poultry by-product meal or feather meal, with the exception of gross energy. However, spent hen meal was unpalatable. The ADCs in these ingredients were variable, and this variability must be taken into account when these ingredients are formulated into feeds for fish.

This study was conducted to determine the in-vivo and in-vitro apparent digestibility coefficient of nutrients in raw and processed Hibiscus sabdariffa (Roselle) seed meals. In the in-vivo digestibility, Acid Insoluble Ash (AIA) was used as an indicator. Five experimental diets were formulated using raw roselle, (RR) soaked roselle, (SR) boiled roselle,(BR) sprouted roselle (SR) and fermented roselle (FR) to feed Oreochromis niloticus fingerlings inside fifteen plastic aquaria of 60cm x 50cm x 30cm dimension with 120L water holding capacity to determine the effect of raw and processed roselle on the digestibility of the oil seed. Ten fingerlings of O. niloticus (initial total weight 0.60kg) were stocked in each aquarium with three replicates. The results obtained revealed that the apparent digestibility coefficient (ADC) for protein were highest in fermented roselle (88.20%) followed by boiled roselle (86.40%), sprouted roselle (85.74%), soaked roselle was 81.43% and the raw roselle was the least with 79.57%. The ADC for Crude Lipid was 57.90%, 50.17%, 57.80%, 50.54% and 49.75% for fermented roselle, sprouted roselle, boiled roselle, soaked roselle and raw roselle respectively. The results for the digestibility coefficient of roselle seed meals analyzed in-vitro using casein as the control showed that the ADC for protein were also highest in fermented, roselle 90.50%, followed by boiled roselle (85.00%), soaked roselle (75.00) and lastly raw roselle (70.00%). There were significant differences (p < 0.05) in all the processing methods. In both the in-vivo and in-vitro digestibility, fermented roselle presented the highest digestibility of 88.20% and 90.50% respectively. These values compares favorably with other oil seed meals and legumes used in aquafeeds.Keywords: Digestibility, Nile Tilapia, Roselle

Digestive effects and intestinal health of ponies fed a complete single diet, thermally processed and containing long fiber

Apparent digestibility of nutrients, energy, essential amino acids and fatty acids of juvenile Atlantic salmon (Salmo salar L.) diets containing whole-cell or cell-ruptured Chlorella vulgaris meals at five dietary inclusion levels

A study was conducted to determine in-vivo apparent digestibility coefficient of nutrients in processed jackbean meal. Acid Insoluble Ash (AIA) was used as an indicator. The test diets consist of the seed meal replacing soybean meal at 10, 20, 30 and 40% to serve as test diets D10, D20, D30, and D40 respectively. A diet called as diet CTR, without jackbean meal served as control. These diets were fed to Tilapia Oreochromis niloticus fingerlings (6.37 ± 0.07 g) in a glass tanks for 5 weeks. Faecal collection was made by siphoning after four hours of each feeding. Proximate analysis of both diets and faecal samples were carried out for crude protein, lipid, crude fiber, energy, and AIA. These were used to calculate the digestibility coefficient of nutrients. There was no significant difference (p > 0.05) in lipid and organic matter digestibility of the fish fed control diet and test diets. Significant (p < 0.05) variations occurred in nitrogen-free extracts, protein and crude fiber digestibility of fish fed control diet and the test diets. Key words: Digestibility, in vivo, jackbean, Oreochromis niloticus.

An experiment was conducted to determine effects of feeding levels on growth performance, feed utilization, body composition, and apparent digestibility coefficients (ADCs) of nutrients for juvenile grouper Epinephelus coioides (initial weight, 10.31 ± 0.36 g). Grouper were fed a practical diet from 0 (starvation) to 3.5% (at 0.5% increments) body weight per day (bw/d) for 8 wk. ANOVA indicated that growth performance, feed utilization, body composition, and ADCs of dry matter, protein, and energy were significantly (P &lt; 0.05) affected by feeding levels. Survival was the lowest for the starvation group and for fish fed a ration of 0.5% bw/d. Final mean body weight, weight gain (WG), specific growth rate, and metabolic growth rate increased with feeding rate from 0 to 2.5% bw/d (P &lt; 0.05) and showed no significant differences above the level (P &gt; 0.05). Feed conversion rate was significantly lower at a feeding level of 2.0% bw/d than above and below the level (P &lt; 0.05). Protein efficiency ratio was markedly highest at the 2.0% bw/d ration level (P &lt; 0.05). Lipid contents of whole body, muscle, and liver increased with increasing feeding rates from 0 to 3% bw/d and showed a slight decline at the feeding level of 3.5% bw/d. Protein contents of whole‐body composition, muscle, and liver remained relatively stable with the different ration amount with the exception of fish fed a ration of 0.5% bw/d, at which grouper possessed significantly lower body protein concentration (P &lt; 0.05). Condition factor, viscerosomatic index, and hepatosomatic index were the lowest for fish fed 0.5% bw/d and tended to increase with the increasing feeding levels. ADCs of dry matter, protein, and energy decreased with increasing feeding levels from 0 to 2.5% bw/d 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 grouper were 2.5% bw/d and 0.25% bw/d, respectively.

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.

To evaluate the effects of a therapeutic gastrointestinal diet on the apparent digestibility coefficients (ADCs), metabolizable energy (ME), and palatability of the diet, fermentative metabolites, and fecal microbiome of dogs. Sixteen 1-year-old healthy Beagles were used. All animals consumed a control diet for healthy adult dogs for 20 days. On day 21, 8 dogs changed to a therapeutic gastrointestinal diet (test diet), and 8 dogs continued receiving the control diet for 35 days. Fresh feces were collected on days 0, 3, 15, and 30 after changing to the test diet for pH, fermentative metabolites, and microbiota analysis. Feces were collected for ADCs and ME analysis of the diets (days 31 through 35). The palatability of the control and test diets was compared at the end of the study. The test diet presented greater ADCs of nutrients and ME and resulted in lower fecal pH and greater fecal concentrations of ammonia, total biogenic amines, total short-chain fatty acids, and butyrate. β-Diversity analysis revealed distinct fecal microbiome profiles between the diets on days 3, 15, and 30, with a greater abundance of Turicibacter and Faecalibacterium and lower Streptococcus in the test group. Dogs preferred the test to the control diet in the palatability test. The test diet presented high ADCs of nutrients, high palatability, and beneficially modulated the fecal microbiome and fermentative metabolites of dogs. Providing a highly digestible and palatable diet with functional ingredients may contribute to the treatment of gastrointestinal disorders of dogs.

Corn distiller's dried grains with solubles: Apparent digestibility and digestive enzymes activities in European seabass (Dicentrarchus labrax) and meagre (Argyrosomus regius)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake, growth performance, and digestion of juvenile Japanese flounder (Paralichthys olivaceus). Four isonitrogenous (49% crude protein) and isoenergetic (20.1 MJ kg−1) diets were formulated to contain four graded levels of soy isoflavones, namely, 0, 1, 4 and 8 g soy isoflavones in 1 kg of diet. Each diet was randomly fed to triplicate tanks of fish (Initial average weight: 2.58 g ± 0.01 g), and each tank was stocked with 35 fish. No significant difference was observed among diets with levels of 0, 1 and 4 g kg−1 soy isoflavones in feed intake, weight gain, feed efficiency ratio (FER), proximate composition of fish whole body and apparent digestibility coefficients (ADC) of nutrients and energy (P>0.05). However, high dietary soy isoflavones level (8 g kg−1) significantly depressed weight gain, FER, whole-body crude lipid content of fish and ADC of nutrients (P<0.05). These results indicate that high level of dietary soy isoflavones (above 4 g kg−1) significantly depresses growth responses and FER of Japanese flounder. However, as the content of soy isoflavones in soybean meal is around 1 to 3 g kg−1, the adverse effects might be neglected when soybean products are used as a fish feed ingredient.