Apparent Digestibility Coefficients Of Phosphorus Research Articles

Influences of dietary protein source and extrusion temperature on growth performance, tissue composition, and gut microbiota of grass carp Ctenopharynodon idellus

This study aimed to investigate the effects of dietary protein source (DPS) and extrusion temperature (ET) on the physical qualities of extruded grass carp feed and the growth performance, tissue composition, and gut microbiota of these animals. We used a 2 × 2 factorial experimental design, with DPSs consisting of mostly plant or fishmeal proteins extruded at 120 °C (DP1 and DA1 diets) or 140 °C (DP2 and DA2 diets) for grass carp. The growth trial was performed for 9 weeks, and the gut microbiota trial lasted 4 weeks. Compared with the fishmeal-based diets, the plant protein-based diets produced higher expansion ratios (P < 0.001). A high ET also improved the expansion ratio (P < 0.001) and significantly decreased the feed pellet bulk density (P < 0.001). The DP2 diet had the highest hardness and water solubility index and the lowest water absorption index. The DP1 diet exhibited the lowest protein and phosphorus apparent digestibility coefficients (ADCs). The ET significantly affected the ADCs for the plant protein-based diets, but not for the fishmeal-based diets. Grass carp fed the DP1 diet presented the lowest weight gain and specific growth ratio. The interactions between DPS and ET affected the final body weight (P = 0.030), protein efficiency ratio (P = 0.011), and feed efficiency (P = 0.016), and these indices were significantly greater in grass carp fed the DP2 diet than in those fed the DP1 diet. However, DPS and ET did not affect the concentrations of crude protein or amino acids in the dorsal muscle. Compared with grass carp fed plant-based diets, those fed fishmeal-based diets presented greater fat contents in the muscle (P = 0.011) and liver P = 0.037), and a greater hepatosomatic index (P = 0.003). The interaction of DPS and ET influenced the viscerosomatic index (VSI, P = 0.001), with the highest VSI found after feeding the DA2 diet. DPS (P = 0.001) but not ET (P = 0.172) significantly affected the gut microbial communities, although the plant protein-based diets with increased ET resulted in more differential taxa and greater differences in the abundances of the core microbiota in grass carp compared to the fishmeal-based diets. These results indicate that improving the ET of plant protein-based diets can alter the physical qualities of the diets, further affecting the gut microbiota, and enhancing the growth performance of grass carp. These findings reveal that higher ETs are needed for plant protein-based diets than for fishmeal-based diets, which is a valuable guideline for feed production.

Effects of Dietary Phosphorus Levels on Growth Performance, Phosphorus Utilization and Intestinal Calcium and Phosphorus Transport-Related Genes Expression of Juvenile Chinese Soft-Shelled Turtle (Pelodiscus sinensis).

A 60-day feeding trial was performed to assess the effects of dietary phosphorus levels on growth performance, body composition, phosphorus utilization, plasma physiological parameters and intestinal Ca and P transport-related gene expression of juvenile Chinese soft-shelled turtle (P. sinensis). Four diets containing available P at graded levels of 0.88%, 1.00%, 1.18% and 1.63% (termed as D0.88, D1.00, D1.18 and D1.63, respectively) were formulated and each diet was fed to turtles (5.39 ± 0.02 g) in sextuplicate. The turtles were randomly distributed to 24 tanks with 8 turtles per tank. The results indicated that final body weight, specific growth rate, feed conversion ratio and protein efficiency ratio performed best in turtles fed 1.00% available P diet. The crude lipids of the whole body exhibited a decreasing trend with the dietary available P, whereas the calcium and phosphorus of the whole body and bone phosphorus showed an opposite tendency. The apparent digestibility coefficient of phosphorus declined with the dietary available P. Turtles fed 1.00% available phosphorus had the highest phosphorus retention ratio compared with other treatments. Simultaneously they had significantly lower phosphorus loss than turtles fed D1.18 and D1.63 and had no differences in this respect from turtles fed a low-phosphorus diet. It was noteworthy that the lowest plasma calcium concentrations, and alkaline phosphatase activities in plasma and liver, were discovered in turtles fed the diet containing 1.63% available phosphorus. In addition, the high-phosphorus diet resulted in significantly down-regulated expression of intestinal phosphorus and calcium transport-related key genes. In conclusion, the available phosphorus requirement of juvenile P. sinensis was determined at 1.041% (total phosphorus was 1.80%) based on quadratic regression of weight gain rate, and excessive dietary phosphorus stunted turtle growth possibly via inhibiting intestinal calcium absorption.

Nutritional value of different insect larvae meals as protein sources for European sea bass (Dicentrarchus labrax) juveniles

Apparent digestibility coefficients (ADCs) of five commercially available insect larvae meals, H. illucens (HI and HId), T. molitor (TM and TMd) and a locust meal (LM), obtained from different producers, were assessed in European sea bass (Dicentrarchus labrax) juveniles. Each experimental diet was obtained by replacing 20% of a commercial-based diet used as reference (DREF), with 1% of chromic oxide added, by a test ingredient. Each diet was fed to quadruplicate groups of fish (initial weight: 33 ± 1 g) and, after an acclimatization period, daily collection of faeces was performed during 12 days. Dry matter ADC was highest in TM (85%) and lowest in LM (40%). Protein ADC was high in TMd (93%); intermediate in HId and TM (87 and 89%, respectively); and moderate in LM and HI (74 and 76%, respectively). Overall, the ingredient with highest digestible total essential amino acids (EAAs) content was TMd, followed by TM which was higher than HId; HI had a moderate amount of digestible EAAs, and LM had the lowest values. Fat ADC was highest for HId, TMd and TM (93%–95%). Energy and phosphorus ADC were highest in TMd (84% and 91%, respectively) and lowest in LM (53% and 27%, respectively). In conclusion, the high protein level, high protein digestibility and high amount of digestible EAAs of TM and TMd (> 89%) suggests that Tenebrio molitor larvae meals are the most promising protein sources tested for European sea bass, with potential to replace fishmeal without impairing nutrient digestibility.

Partial replacement of fish meal by soybean meal with or without methionine and phytase supplement in diets for juvenile Chinese sucker,Myxocyprinus asiaticus

This study was designed to evaluate the effects of using soybean meal supplemented with or without methionine (M) and graded levels of phytase (P) to replace high-level (60%) fish meal in the diets for juvenile Chinese sucker. Seven experimental diets (about 430 g kg−1 crude protein on dry matter basis) were formulated from practical ingredients. The control diet (FM) was formulated to contain 400 g kg−1 white fish meal (FM), whereas in the other six diets (diets 2–7), soybean meal (SBM) was used to replace 60% fish meal with or without methionine (3 g kg −1) and 0,500, 1000, 1500 and 2000 U kg−1 phytase (designated as SBM, SM, SMP500, SMP1000, SMP1500 and SMP2000, respectively). Results from the feeding trial indicated that SBM without any methionine or phytase supplement replacing about 60% FM significantly affected the growth of fish (P < 0.05). Weight gain of fish fed diet SM was significantly higher than the fish fed diet SBM, but still much lower than fish fed the control diet (P < 0.05). SBM with methionine and phytase supplement significantly improved the growth of fish and apparent digestibility coefficients of phosphorus compared with the groups which fed diet SBM and diet SM (P < 0.05). Weight gain of fish fed SMP1000, SMP1500 and SMP2000 had no significant difference than fish fed control diet. Furthermore, fish fed SMP1500 showed optimum weight gain and ADC of phosphorus between these three groups. This suggested that soybean meal with 3 g kg−1 methionine and 1500 U kg−1 phytase supplement could successfully replace 60% fish meal in the diet for juvenile Chinese sucker without affecting growth and enhanced the apparent digestibility coefficient of phosphorus.

Effects of the Dietary Microbial Phytase Supplementation on Bioavailability of Phosphorus in Juvenile Olive Flounder Paralichthys olivaceus Fed Soybean Meal based Diets

An 8 weeks feeding trial was carried out to evaluate the effects of dietary microbial phytase (P) supplementation on nutrient digestibility, and body composition in juvenile olive flounder Paralichthys olivaceus fed soybean meal-based diets. Seven experimental diets were formulated to be isonitrogenous and isocaloric to contain 50.0% crude protein (CP) and 16.7 kJ of available energy/g with or without dietary phytase supplementation. White fish meal (FM) provided 92.4% of the total protein in the basal diet (S0), in the other 6 diets, 30% or 40% FM protein was replaced by soybean meal: 70% FM + 30% soybean meal (S30); 70% FM + 30% SM + 1000 U phytase/kg diet (S30P1000); 70% FM + 30% SM + 2000 U phytase/kg diet (S30P2000); 60% FM + 40% SM (S40); 60% FM + 40% SM + 1000 U phytase/kg diet (S40P1000); and 60% FM + 40% SM + 2000 U phytase/kg diet (S40P2000). After two weeks of the conditioning period, triplicate groups of 25 fish initially averaging 6.15 ± 0.04 g (mean ± S.D.) were randomly distributed into the aquarium and were fed one of the experimental diets for 8 weeks. After feeding trial, supplementation of phytase significantly improved the apparent digestibility coefficients of phosphorus in flounder diets ( P<0.05) containing 30% and 40% soybean meal regardless the levels. However, phytase had no significant influence on growth performance and whole body composition of fish. Based on the experimental results, we conclude that dietary supplementation of phytase could improve the apparent digestibility coefficient of phosphorus in olive flounder.

A comparison of the effect of dietary fungal phytase and dicalcium phosphate supplementation on growth performances, feed and phosphorus utilization of tra catfish juveniles (Pangasianodon hypophthalmusSauvage, 1878)

Six isonitrogenous (320 g kg−1) and isolipidic (60 g kg−1) diets were formulated with graded levels (0, 5, 10 and 15 g kg−1) of dicalcium phosphate (DCP) and fungal phytase (750 and 1500 FTU kg−1 diet). Tra catfish (Pangasianodon hypophthalmus), 9.6 g, were fed the diets for 12 weeks. Each experimental diet was fed to eight replicates of fish to apparent satiation. At the end of the trial, fish fed the diets containing 15 g kg−1 DCP, 750 and 1500 FTU kg−1 phytase had higher growth performances, protein efficiency ratio and phosphorus retention than those fed the control diet, 5 g kg−1 DCP and 10 g kg−1 DCP diets (P < 0.05). Whole body ash and phosphorus concentration of fish fed the 10 g kg−1 DCP and 15 g kg−1 DCP diets were significantly higher than those of fish fed the control diet. Higher apparent digestibility coefficient of phosphorus was observed in fish fed the phytase supplemented diets. The present results indicate that supplementation of phytase at 750 FTU kg−1 and 1500 FTU kg−1 improves growth performances, feed and phosphorus utilization. The supplementation can completely replace dicalcium phosphate or other phosphorus sources in tra catfish feed and reduce the phosphorus discharge into environment.

Digestibility and bioavailability of phosphorus from spray-dried yeasts in the diet of starting pigs (15-30 kg)

Two experiments were carried out to determine the bioavailability of phosphorus in two spray-dried yeasts - sugarcane yeast (SCY), and sugarcane yeast + brewer's yeast (SCBY) - in starting pigs, by comparing different methods (Apparent Digestibility Coefficient of Phosphorus - ADCP; True Digestibility Coefficient of Phosphorus - TDCP; slope ratio; and standard curve). In experiment I, a digestibility assay were carried out using 30 cross breed pig with initial weigh of 22.69 ± 4.24kg, allotted in a completely randomized design. The mean ADCP and TDCP values were 62.68 and 64.15% for SCY and 77.01 and 79.33% for SCBY. ADCP and TDCP for SCBY were higher (P&lt;0.05) than the values for SCY. In Experiment II, a growth test was conducted, 56 crossbred piglets, were utilized, with initial live weight of 15.11 ± 3.43kg, allotted in a completely randomized design, with seven treatments, four replications, and two pigs per experimental unit. The treatments consisted of a basal diet without supplementation with P and the same diet including supplementation with two levels of P (0.053% and 0.105%) from dicalcium phosphate, SCY and SCBY. The relative bioavailability mean value of 57.23% for SCY and 91.96% for SCBY, corresponding to 0.30% and 0.40% of available phosphorus, respectively.

Influence of soaking, fermentation and phytase supplementation on nutrient digestibility in pigs offered a grower diet based on wheat and barley

AbstractThe effects of 1-h soaking, fermentation and phytase supplementation of a pig diet based on wheat and barley on ileal and total tract apparent digestibility in growing pigs fitted with a post valve T-caecum (PVTC)-cannula were studied. Eight animals in a two-period change-over design were used, subjecting four animals to each treatment (dry, soaked, microbial phytase supplemented or fermented diet). Acid insoluble ash was used as an indigestible marker for calculating apparent digestibility coefficients. Fermentation improved (P&lt;0·05) the ileal apparent digestibility coefficients of organic matter (OM), nitrogen and amino acids, while there was no effect of 1-h soaking and phytase supplementation. The total tract apparent digestibility coefficient of OM was also improved by fermentation. The ileal apparent digestibility coefficient of phosphorus (P) was higher for fermentation (P&lt;0·05) than for dry food and 1-h soaking. The total tract apparent digestibility coefficient of P was higher (P&lt;0·05) for treated food (soaked, fermented and supplemented with microbial phytase) compared with dry food. Fermentation improved (P&lt;0·05) the ileal apparent digestibility coefficient of calcium compared with dry and soaked food, and had no effect on the total tract apparent digestibility coefficient of calcium. Food inositol phosphates were affected by treatment (P&lt;0·05), with a reduction of P bound to inositol hexaphosphate (IP6) of 10% in the 1-h soaked food and of 80% in the fermented food. Degradation of IP6in the gastro-intestinal tract of the animals was lower in the fermented food than in the other treatments. The content of neutral-detergent fibre in the food was reduced (P&lt;0·05) in the soaked and fermented food by 4% and 14%, respectively, compared with the dry food. In conclusion, fermentation of food can improve digestibility of OM, degrade IP6and increase ileal digestibility of phosphorus, nitrogen and amino acids.

Valor nutricional da silagem de grãos úmidos de milho com diferentes graus de moagem para leitões na fase de creche

Utilizaram-se 72 leitões mestiços (Landrace x Large White), com peso inicial médio de 7,1kg, no experimento de desempenho e 20 leitões mestiços, com peso inicial médio de 18,9kg, no experimento de digestibilidade para avaliar a silagem de grãos úmidos de milho com diferentes granulometrias para leitões em fase de creche. O delineamento experimental foi em blocos ao acaso. Em ambos os experimentos avaliaram-se o valor nutricional das silagens com diâmetro geométrico médio (DGM) das partículas de 979, 1168 e 2186µm e do milho seco com DGM das partículas de 594µm. Na fase de zero ao oitavo dia, a silagem proporcionou menor consumo diário de ração (CDR) em relação ao milho seco, e foi verificado aumento linear no CDR com o aumento da granulometria da silagem. A silagem com granulometria média e grossa proporcionou melhora na conversão alimentar (CA) em relação ao milho seco, mas não foi observada diferença no ganho diário de peso (GDP). Para o período total, não foram observadas diferenças estatísticas para CDR e GDP, entretanto a silagem proporcionou melhora na CA em relação ao milho seco havendo efeito linear crescente da granulometria da silagem sobre a CA. A granulometria da silagem não influenciou nos coeficientes de digestibilidade aparente (CDA) da matéria seca e da proteína bruta, porém proporcionou maiores CDA do fósforo e valores de energia digestível em relação ao milho seco. O CDA do cálcio e os valores de energia metabolizável foram maiores para a silagem com granulometria fina e média, comparado ao do milho seco. Houve redução linear do CDA do cálcio com o aumento da granulometria da silagem.

Dietary microbial phytase increased the phosphorus digestibility in juvenile Korean rockfish Sebastes schlegeli fed diets containing soybean meal

This study was conducted to evaluate the effects of dietary microbial phytase supplementation on nutrient digestibility, growth performance and body composition in juvenile Korean rockfish fed soybean meal-based diets. Nine experimental diets were formulated to be isonitrogenous and isocaloric to contain 48.6% crude protein (CP) and 15.9 kJ of available energy/g with or without dietary phytase (Natuphos-5000™, BASF, NJ, USA) supplementation. White fish meal (FM) provided 89.1% of the total protein in the basal diet (S 0), in the other eight diets, 30 or 40% FM protein was replaced by soybean meal: 70% FM+30% soybean meal (S 30); 70% FM+30% 1000 U phytase pretreated SM (S 30PP 1000); 70% FM+30% SM+1000 U phytase/kg diet (S 30P 1000); 70% FM+30% SM+2000 U phytase/kg diet (S 30P 2000); 60% FM+40% SM (S 40); 60% FM+40% 1000 U P tre SM (S 40PP 1000); 60% FM+40% SM+1000 U phytase/kg diet (S 40P 1000); and 60% FM+40% SM+2000 U phytase/kg diet (S 40P 2000). After 2 weeks of the adaptation, triplicate groups of 20 fish initially averaging 7.25±0.04 g (mean±S.D.) were randomly distributed into the aquarium and were fed one of the experimental diets for 8 weeks. By the end of the 8-week feeding trial, supplementation of phytase significantly improved the apparent digestibility coefficient (ADC) of phosphorus in rockfish diets ( P<0.05) containing 30% and 40% soybean meal regardless of the level and method of phytase supplementation. Supplementation of phytase significantly increased the ADC of dry matter in diets containing 30% soybean meal ( P<0.05). However, phytase had no influence on growth performance and whole body composition of fish. The pretreatment of soybean meal with 1000 U phytase improved weight gain (WG) when 30% fish meal protein was replaced by soybean meal. Based on the experimental results, we conclude that supplementation of phytase can improve the apparent digestibility coefficient of phosphorus in Korean rockfish.

Apparent digestibility coefficients of nutrients in brewer's and rendered animal by-products for rainbow trout (Oncorhynchus mykiss (Walbaum))

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.