Dietary Phosphorus Research Articles

Effect of dietary calcium and phosphorus restriction during grower period on growth performance, carcass traits, blood and bone parameters and broiler chickens adaptation in finisher period

Effect of dietary calcium and phosphorus restriction during grower period on growth performance, carcass traits, blood and bone parameters and broiler chickens adaptation in finisher period

Butter biscuit technology for specialized nutrition

Flour confectionery products are considered one of the most popular food products, but the nutritional value does not allow them to be included in the diet of people leading a healthy lifestyle. The recent trend is the expansion of the flour confectionery products’ range by imparting functional properties. Considering the worldwide growth in the level of alimentary-dependent diseases, it is urgent to develop butter biscuits of increased nutritional value characterized by a reduced sugar content. Improving the butter biscuits technology by introducing non-traditional types of flour and topinambour processing products into the recipe will make it possible to scientifically approach the problem’s solution of the flour confectionery products’ disadvantage of increased nutritional value and reduced calorie content, improve their assortment and ensure widespread consumption in everyday life. The study presents the research results on the technology development of butter biscuits enriched with dietary fiber, minerals and vitamins. The decrease in the recipe sugar content by replacing its part with topinambour syrup is substantiated, as well as the introduction of barley flour, chickpea flour and topinambour fiber into the recipe. The developed butter biscuits are distinguished by a reduced content of granulated sugar and an increased content of dietary fiber, magnesium, calcium, potassium, and phosphorus.

Effects of dietary calcium, phosphorus and microbial phytase on intestinal morphologyin laying hens

Different challenges are being applied in the poultry industry in order to protect animal health and to increase immunity and production. The supplementation of microbial phytase is essential in terms of both reducing the inorganic phytase rate and contributing to the absorption of other minerals. In this study, a newly isolated microbial phytase was added at different concentrations to the diet together with calcium (Ca$^{2+}$) and available phosphorus (AP), and the effects of this supplementation on intestinal absorption capacity and Ca$^{2+}$ binding capacity were investigated via morphological measurements and immunohistochemical examination of the duodenum and ileum. For this purpose, 90 Lohmann LSL-White laying hens were divided into three main diet groups: 1. Standard Ca$^{2+}$ and AP (Ca+AP), 2. Standard Ca$^{2+}$ and low AP (Ca+low AP), and 3. Low Ca2+ and low AP (low Ca+low AP). These three groups were further divided into three phytase subgroups each (without phytase [Phy-], commercial phytase [CP] and microbial phytase [MP]). At the end of the experiment, animals were euthanized, and duodenum and ileum samples were fixed and processed for histological examination. Villus height, crypt depth, total mucosa thickness, and villus width were measured and villus height: crypt depth ratio and villus absorption area were calculated. Caldesmon expression in the duodenum and ileum was also investigated immunohistochemically. The results indicated that villus height, total mucosa thickness, and villus absorption area increased (p ≤ 0.05) in birds fed with Ca+AP+MP. Stronger caldesmon expression was observed in the MP treated groups. We concluded that MP produced from Bacillus megaterium EBD 9-1 bacterium increases the utilization of Ca$^{2+}$ and AP and, thus, can have a beneficial role when these macrominerals are used insufficiently. Ca$^{2+}$, AP, and MP may have positive effects on the intestinal morphology and absorption area when used at optimum amounts.

Phosphate Intake and Removal in Predominantly Vegetarian Patients on Twice-Weekly Hemodialysis.

Hyperphosphatemia is linked to increased mortality and morbidity in patients on hemodialysis. Currently, the phosphate intake and dialytic removal in predominantly vegetarian patients on twice-weekly dialysis is not well studied. This prospective, study recruited patients on twice-weekly dialysis of at least 3 months duration. Baseline clinical variables were measured. Dietary protein and phosphorus intake was assessed using a validated food frequency questionnaire. Phosphate binder use was assessed, hourly blood was collected for serum phosphorus during dialysis, and spent dialysate was collected to estimate cumulative phosphorus removal during the session. Forty (67%) of the 60 patients studied were vegetarians. Twenty-eight (48%) were hyperphosphatemic, and 15 (25%) had serum parathormone (PTH) >500 pg/ml. The mean phosphorus intake was 1247 (±312) mg/day, the mean serum phosphorus was 5.49 (±2.01) mg/dl, and the mean dialytic phosphorus removal was 910 (±383) mg/session. Up to 67% of the study population took calcium-based phosphate binders, 25% took sevelamer carbonate, and 40% took activated vitamin D preparation. The lowest tertiles of phosphorus intake correlated with low energy-adjusted protein intake and hypoalbuminemia. Hyperphosphatemic subjects had better nutritional indices (mid-upper arm circumference and body mass index). Dietary intake and serum phosphorus levels were not mutually associated, but both were strongly correlated with total phosphorus removal in the spent dialysate. Serum phosphorus levels fell by 32% by thefirst hour of hemodialysis. Twice-weekly dialysis is often practised in resource-limited Asian countries. However, due to a predominantly vegetarian diet, hyperphosphatemia was noted only in up to half of the patients, despite twice-weekly hemodialysis schedules. This reinforces the fact that plant-based dietary phosphate is less well absorbed.

The Effect of Different Bone and Analytical Methods on the Assessment of Bone Mineralization to Dietary Phosphorus, Phytase, and Vitamin D in Finishing Pigs

Eight hundred eighty-two pigs (initially 73.2 ± 0.7 lb) were used to evaluate the effects of different bones and analytical methods on the assessment of bone mineralization response to dietary P and vitamin D in growing-finishing pigs. Pens of pigs (20 pigs per pen) were randomized to 1 of 5 dietary treatments in a completely randomized design with 9 pens per treatment. Treatments were formulated to have varying levels of P, phytase, and vitamin D to potentially provide wide differences in bone characteristics. After feeding diets for 112 d, nine pigs per treatment were euthanized for bone, blood, and urine analysis. There were no significant differences for final BW, ADG, ADFI, F/G (P > 0.10), or bone ash (bone ash × bone interaction, P > 0.10) regardless of the ashing method. The response to treatment for bone density and bone mineral content was dependent upon the bone (density interaction, P = 0.053; mineral interaction, P = 0.078). There were no treatment differences for bone density and bone mineral content for metacarpals, fibulas, and 2nd rib (P > 0.05). For 10th rib bone density, pigs fed industry levels of P and vitamin D had increased (P < 0.05) bone density compared to pigs fed NRC levels with phytase, with pigs fed deficient P, NRC levels of P with no phytase, and extra 25(OH)D3 vitamin D (HyD) intermediate. Pigs fed extra vitamin D from HyD had increased (P < 0.05) 10th rib bone mineral content compared to pigs fed deficient P and NRC levels of P with phytase, with pigs fed industry P and vitamin D, and NRC P with monocalcium intermediate. In summary, bone density and bone mineral content responses varied depending on the bone. The difference between bone ash procedures was more apparent than the differences between diets. Differences in bone density and mineral content in response to P and vitamin D were most apparent with the 10th ribs.

The Effect of Bone and Analytical Methods on the Assessment of Bone Mineralization Response to Dietary Phosphorus, Phytase, and Vitamin D in Nursery Pigs

Three hundred-fifty pigs (initially 26.2 ± 1.23 lb) were used to evaluate the effects of bone and analytical methods on the assessment of bone mineralization response to dietary P and vitamin D in nursery pigs. Pens of pigs (5 or 6 pigs/pen) were randomized to 6 dietary treatments in a randomized complete block design with 10 pens per treatment. Treatments were formulated to have varying levels of P, phytase, and vitamin D to provide differences in bone characteristics. After feeding diets for 28 d, eight pigs per treatment were euthanized for bone, blood, and urine analysis. The response to treatment for bone density and ash was dependent upon the bone analyzed (density × bone interaction, P = 0.044; non-defatted bone ash × bone interaction, P = 0.060; defatted bone ash × bone interaction, P = 0.068). Pigs fed 0.19% STTD P had decreased (P < 0.05) bone density and ash (non-defatted and defatted) for all bones compared to 0.44% STTD P, with 0.33% STTD P generally intermediate or similar to 0.44% STTD P. Pigs fed 0.44% STTD P with no vitamin D had greater (P < 0.05) non-defatted fibula ash compared to all treatments other than 0.44% STTD P with added HyD. Pigs fed the three diets with 0.44% STTD P had greater (P < 0.05) defatted 2nd rib ash compared to pigs fed 0.19% STTD P or 0.33% STTD P with no phytase. In summary, bone density and ash responses varied depending on the bone analyzed. Differences in bone density and ash in response to P and vitamin D were most apparent with fibulas and 2nd ribs. The difference between bone ash procedures was more apparent than the differences between treatments. For histopathology, 10th ribs were more sensitive than 2nd ribs or fibulas for detection of lesions.

Longitudinal Study to Find the Association of Serum Phosphorus Level with FGF23 in Three Different Hyperphosphatemia Management Groups of Stage 3 and 4 Chronic Kidney Disease (CKD) Patients.

There is paucity of clinical evidence on target serum phosphorus levels in early chronic kidney disease (CKD). Present longitudinal study was done to find target phosphorus level and its association with fibroblast growth factor (FGF23) in three different hyperphosphatemia management groups. This 1-year, prospective, randomized controlled, open-labelled study was conducted among three equally allocated treatment groups that consisted of 120 screened early CKD patients totally. Group 1 patients were given dietary phosphorus modification (n = 40), group 2 patients were administered calcium-based phosphate binders (n = 40), and group 3 patients were given non-calcium-based phosphate binders (n = 40). Three-monthly dietary assessment, MDRD estimated glomerular filtration rate (eGFR), phosphorus, calcium, iPTH, alkaline phosphatase, and six-monthly FGF23, 2D echocardiography, and X-ray of chest and abdomen were performed. Association of three categories of phosphorus level up to 3.9, 4-5, and >5mg/dl, rate of progression of all parameters, and correlation with FGF23 were studied among all three groups. At baseline, all clinical and biochemical parameters were equally distributed with a controlled nutritional phosphate among all groups. There was no significant difference of FGF23 levels from all the three categories of phosphorus level among all groups. Serum phosphorus at the level of 5 mg/dl was associated with iPTH and eGFR at 1 year. Over 1 year, there was a significant decline in serum phosphorus levels in group 1 (P 0.02), group 2 (P 0.00), and group 3 (P 0.05). FGF23 declined significantly only in group 3 (P 0.00). There was no correlation of FGF23 with serum phosphorus levels (P 0.13). However, FGF23 correlated positively with iPTH (P 0.03, r = 0.19). Serum phosphorus levels upto 5mg/dl had no effect on FGF23 at early CKD stages. Although different treatment groups showed significant phosphorus reduction, non-calcium phosphate binder had a major impact on FGF23 reduction.

Effects of Dietary Salt-Based Minerals and Phosphorus Supplements on Mean Body Weight, Survival Rate and Feed Conversion Ratio of White Shrimp Reared In Brackish Water

This study aimed to examine the impact of dietary salt-based mineral and phosphorus supplements on mean body weight, survival rate, and feed conversion ratio of Litopenaeus vannamei (white shrimp) reared in brackish water. The experiment was performed randomized design with three replicates in each treatment used twelve 40 L rectangular polymethyl methacrylate containers reared 45 days. The four treatments in this study were based on the concentration of salt-based mineral and phosphorus supplements (control or 0 ppm, one ppm, two ppm, and three ppm) in dietary of white shrimp. The results showed that using salt-based mineral and phosphorus supplements in dietary of white shrimp positively impacts mean body weight, survival rate, and feed conversion ratio. Increasing the concentration of salt-based mineral and phosphorus supplements increased mean body weight and survival rate and reduced feed conversion ratio of white shrimp. The mean body weight, survival rate, and feed conversion ratio of white shrimp were achieved with three ppm of dietary salt-based mineral, and phosphorus supplements reared 45 days was 5.98 gr, 88.57%, and 1.45, respectively.

Postdialysis serum phosphate equilibrium in hemodialysis patients on a controlled diet and no binders.

Studies evaluating the change in serum phosphate post hemodialysis (HD) demonstrate an initial decline during dialysis but a rebound post dialysis. However, previous studies were done on usual diet and phosphate binders, with limited number of blood draws, confounding conclusions. We determined serum phosphate reduction, rebound, and equilibrium over 48 h in HD patients consuming a controlled, low phosphorus diet without binders. Serum phosphate (mg/dL) was analyzed before and after a HD treatment and frequently during the ensuing 48 h intradialytic period in the clinical research unit. Thirteen subjects were enrolled and had been off phosphate binders for 10 days and consumed a standardized low phosphate (900 mg/day) diet for 3 weeks prior to the assessments. Linear regression was used to determine relationships between the pre-HD serum phosphate, decline post-HD (post-HD drop); and a 48 h area under curve (AUC) using the trapezoidal method as a measure of overall phosphate levels from the end of dialysis to 48 h post dialysis. Repeated Measures ANOVA with Dunnett's posthoc test was used to determine rebound. Five of 13 subjects returned to >90% of their pre-HD serum phosphate within the first 24 h post-HD, and serum phosphate was 94 ± 0.11% (range 63%-113%) by 48 h after the completion of HD. The 48 h AUC of serum phosphate during the interdialytic period was correlated with both pre dialysis phosphorus (r=0.85; p=0.0002) and the pre-post drop in serum phosphate during dialysis (r=0.69; p=0.0085). In contrast, the net ultrafiltration was not related to the 48 h AUC of serum phosphorus (r=0.20; p=0.51). In hemodialysis patients on standard low phosphorus diet and no phosphate binders, the interdialytic serum phosphorus level, assessed as AUC, is determined by the pre dialysis phosphorus and net-change in serum phosphorus during the dialysis treatment, but not the ultrafiltration volume [Correction added on 25 January, after first online publication: In the last sentence of the Abstract, the word "potassium" has been replaced with "phosphorus" to improve accuracy.].

Phosphorus Restriction in Brooding Stage Has Continuous Effects on Growth Performance and Early Laying Performance of Layers.

Simple SummaryPhosphorus plays a critical role in bone and eggshell formation. Dietary phosphorus oversupply depletes non-renewable natural resources and causes environmental concerns in animal husbandry. This study evaluated the effects of phosphorus restriction in the brooding stage and subsequent recovery on growth performance, tibia development and early laying performance of layers. Phosphorus restriction decreases growth performance and bone characters in the brooding stage, and the adverse effects on body weight and early laying performance do not disappear after phosphorus supplementation. These findings give a foundation and new perspective on low phosphorus feeding strategies in the production of layers.This study evaluated the effects of phosphorus restriction in the brooding stage and subsequent recovery on growth performance, tibia development and early laying performance of layers. 360 one-day-old hens were randomly divided into 4 groups with 6 replicates and 15 chicks per replicate. Chicks were fed diets containing 0.13% (L), 0.29% (M), 0.45% (N), 0.59% (H) non-phytate phosphorus (nPP) from 1 to 8 weeks of age. From 9 to 20 weeks of age, the L and N group were divided into two groups fed normal level phosphorus (n, 0.39% nPP) and high-level phosphorus (h, 0.45% nPP) separately, then all the birds were fed a normal diet (0.39% nPP) from 21 to 26 weeks of age. Four treatments were tested: Ln, Lh, Nn, and Nh. The lower body weight, average daily feed intake, tibia length and daily tibial increment were observed in the L group (p < 0.05) and the ratio of feed to gain was significantly increased in the L group at 8 weeks of age (p < 0.05). In addition, the fresh and degreased tibia weight, bone ash, Ca content in the tibia and P content in the ash and tibia were significantly decreased in the L group at 8 weeks of age (p < 0.05). After compensatory processes, there was no significant difference in tibia characters; however, body weight in the Ln group was significantly lower than in the Nn group (p < 0.05) and was significantly lower in the Lh group than the Nn group (p < 0.01) and Nh group (p < 0.05). In addition, the laying rate and average daily egg mass in the Lh group were lower than Nn and Nh (p < 0.05). In conclusion, severe dietary phosphorus restriction impaired growth performance and bone mineralization in the brooding stage. Subsequent phosphorus supplementation could not alleviate this adverse effect on body weight, which continued to affect egg production. These findings give a foundation and new perspective on a low phosphorus feeding strategy in layer production.

Use of Micro-CT Imaging to Assess Ventral Mandibular Cortical Thickness and Volume in an Experimental Rodent Model With Chronic High-Phosphorus Intake.

Adverse effects of high dietary phosphorus on bone health have been observed in both animal and human studies. The aim of the investigation was to examine chronic effects of high phosphorus diet on the apical mandibular cortical thickness and volume in a hystricomorph rodent (Octodon degus) using microcomputed tomography. Male degus were randomly divided into two groups fed by different mineral contents from the age of 12 weeks till the age of 17 months. The micro-CT scanning and wall thickness analysis were applied on the region of the mandible exactly under the apices of the 4th premolar tooth, first molar tooth, and second molar tooth in two animals from each group. General overview and mapping of the ventral mandibular bone thickness revealed pronounced bony mandibular protrusions in all the animals fed a high-phosphorus diet with obvious bone thinning apically to the 4th premolar and first and second molar tooth apices. Mandibular bone volume and thickness located apically to the premolar and molars were statistically significantly smaller/thinner in the group fed by a high phosphorus diet. The thinnest bone measured 0.004 mm, where the mandibular 4th premolar tooth almost perforated the mandibular cortex. Similar studies of metabolic bone disease and its influence on alveolar bone were also published in rats and mice. The influence of different environmental, infectious, or metabolic factors on the growing tooth, alveolar bone formation, and bone pathologies must be done experimentally on growing animals. In contrast, degus have continuously growing dentition, and the effect of any of the above listed factors can be studied in this animal model at any age and for longer time periods.

The effect of dietary phosphorus load and food matrix on postprandial serum phosphate in hemodialysis patients: a pilot study

Background: Potential dietary strategies for controlling hyperphosphataemia include the use of protein sources with lower phosphorus bioavailability such as pulses and nuts, focus on phosphorus to protein ratios and the avoidance of all phosphate additives. Methods: We conducted a controlled crossover feeding study in 8 haemodialysis (HD) patients to investigate the acute postprandial effect of a modified versus standard low phosphorus diet for one day on serum phosphate, potassium and intact parathyroid levels in prevalent HD patients. Each participant consumed the modified diet on one day and the standard diet on a second day one week apart. The modified diet included beef and less dairy, with a lower phosphorus to protein ratio, as well as plant-based protein, whole grains, pulses and nuts containing phytates which reduces phosphorus bioavailability. Both diets were tailored for each participant to provide 1.1g protein/kg ideal body weight. Participants provided fasting bloods before breakfast, a pre-prandial sample before the lunch time main meal and samples at one-hour intervals for the four hours after the lunch time main meal, for analysis of phosphate, potassium and intact parathyroid hormone (iPTH). Results: At four hours post the lunch time main meal on each study day, individuals on the modified diet had serum phosphate readings 0.30 mmol/l lower than when on the standard diet (p-value = 0.015, 95% confidence interval [CI] -0.57, -0.04). The corresponding change in serum potassium at four hours was a decrease of 0.675 mmol/l (p-value = 0.011, CI -1.25, -0.10). Conclusions: Decreases in both serum phosphate and serum potassium readings on a modified low phosphorus diet encourage further larger studies to explore the possibility of greater food choice and healthier plant-based diets in HD patients. ClinicalTrials.gov registration: NCT04845724 (15/04/2021)

Effect of phosphorus on growth performance, intestinal tight junctions, Nrf2 signaling pathway and immune response of juvenile mirror carp (Cyprinus carpio) fed different α-ketoglutarate levels

Previous research has shown that dietary α-ketoglutarate (AKG) supplementation can promote growth performance, phosphorus metabolism, and skeletal development of juvenile mirror carp (Cyprinus carpio) fed low phosphorous diets. In the current study, we tested the hypothesis that 1% AKG dietary supplementation reduces the dietary phosphorus requirements of juvenile mirror carp. A total of 12 experimental isoproteic and isolipidic diets containing available phosphorus levels of 0.21%, 0.38%, 0.55%, 0.72%, 0.89%, and 1.07% dry matter with either 0 or 1% AKG supplementation were used in the study. A total of 1080 juvenile fish of similar initial weight (0.90 ± 0.03 g) were selected and randomly assigned to 36 tanks. There were three replicates for each experimental group, with a density of 30 fish per tank. Fish were fed to satiation for 8 weeks. The results indicated that fish fed the diet supplemented with 1% AKG showed a significant increase in final body weight (FBW), weight gain rate (WGR), feed intake (FI) and phosphorus intake (PI) compared to the diet without AKG (P < 0.05). FBW and WGR increased significantly with increasing available phosphorus levels from 0.21% to 0.89% (P < 0.05). The mRNA expression of ZO-1, claudin 11, and occludin was significantly increased by dietary AKG and phosphorus (P < 0.05). The mRNA expression of Nrf2, GPx1a, and CAT in the Nrf2 signaling pathway was significantly increased by dietary AKG and phosphorus (P < 0.05). The expression levels of IL-10 and TGF-β2 were significantly increased by dietary AKG and phosphorus, but the expression levels of IL-1β, IL-8, IL-10, TNF-a and NF-κB were significantly decreased with dietary AKG and phosphorus supplementation (P < 0.05). Based on second-order polynomial regression analysis of WGR against dietary phosphorus levels, the optimal dietary phosphorus level was found to be 0.79% of dry feed for juvenile mirror carp fed a diet with 1% AKG supplementation and 0.93% of dry feed without AKG supplementation. This study confirmed that AKG supplementation can reduce the phosphorus requirements of juvenile mirror carp by promoting growth performance, intestinal tight junctions, Nrf2 signaling pathways and immune response.

Effects of dietary wheat middlings and supplemental phosphorus on growth of turbot, Scophthalmus maximus Linnaeus, 1758

This study was carried out to determine the effects of replacement of wheat flour with wheat middling (WM) and supplemental phosphorus at a level of 1% on growth and nutrient utilization, whole body, fillet, viscera and liver proximate compositions in turbot, (Scophthalmus maximus Linnaeus, 1758). The control diet was based on a mixture of three fish meals and whole wheat flour. Fish with an average initial weight of 266.67±0.72 g were fed experimental diets for 9 weeks. Each treatment was tried in four replicates. At the end of the experiment, there were no significant effects of the treatment on growth rate, nutrient utilization parameters such as feed intake, feed conversion ratio, protein efficiency rate, nitrogen, lipid and energy gains and retentions, hepato-somatic index, viscero-somatic index, condition factor, whole body (except dry matter which was significantly lower in P added diet than the control) and organ nutrient compositions. The findings suggest that WM can totally replace wheat flour and there is a tendency of a positive contribution of dietary P supplementation on the response variables.

Optimization of Dietary Phosphorus Utilization for Eco-friendly Pig Production: An Overview

Optimization of Dietary Phosphorus Utilization for Eco-friendly Pig Production: An Overview

Development of an optimal grocery list based on actual intake from a cross-sectional study of First Nations adults in Ontario, Canada.

A multi-stage sampling strategy selected 1387 on-reserve First Nations adults in Ontario. Foods from a 24-hour dietary recall were assigned to the 100 most common food groups for men and women. Nutrients from market foods (MF) and traditional foods (TF) harvested from the wild as well as MF costs were assigned based on the proportions of total grams consumed. Linear programming was performed imposing various constraints to determine whether it was possible to develop diets that included the most popular foods while meeting Institute of Medicine guidelines. Final models were obtained for both sexes with the top 100 food groups consumed while limiting the nutrient-poor foods to no more than the actual observed intake. These models met all nutrient constraints for men but those for dietary fibre, linoleic acid, phosphorus, and potassium were removed for women. MF costs were obtained from community retailers and online resources. A grocery list was then developed and MF were costed for a family of 4. The grocery list underestimated the actual weekly food cost because TF was not included. Contemporary observed diets deviated from healthier historic First Nations diets. A culturally appropriate diet would include more traditional First Nations foods and fewer MF. Novelty: Linear programming is a mathematical approach to evaluating the diets of First Nations. The grocery list is representative of food patterns within Ontario First Nations and can be used as an alternative to the nutritious food basket used for public health food costing.

Solid-state fermented brewer's spent grain enzymatic extract increases in vitro and in vivo feed digestibility in European seabass

Brewer’s spent grain (BSG) is the largest by-product originated from the brewery industry with a high potential for producing carbohydrases by solid-state fermentation. This work aimed to test the efficacy of a carbohydrases-rich extract produced from solid-state fermentation of BSG, to enhance the digestibility of a plant-based diet for European seabass (Dicentrarchus labrax). First, BSG was fermented with A. ibericus to obtain an aqueous lyophilized extract (SSF-BSG extract) and incorporated in a plant-based diet at increasing levels (0—control; 0.1%, 0.2%, and 0.4%). Another diet incorporating a commercial carbohydrases-complex (0.04%; Natugrain; BASF) was formulated. Then, all diets were tested in in vitro and in vivo digestibility assays. In vitro assays, simulating stomach and intestine digestion in European seabass, assessed dietary phosphorus, phytate phosphorus, carbohydrates, and protein hydrolysis, as well as interactive effects between fish enzymes and dietary SSF-BSG extract. After, an in vivo assay was carried out with European seabass juveniles fed selected diets (0—control; 0.1%, and 0.4%). In vitro digestibility assays showed that pentoses release increased 45% with 0.4% SSF-BSG extract and 25% with Natugrain supplemented diets, while amino acids release was not affected. A negative interaction between endogenous fish enzymes and SSF-BSG extract was observed in both diets. The in vivo digestibility assay corroborated in vitro data. Accordingly, the dietary supplementation with 0.4% SSF-BSG increased the digestibility of dry matter, starch, cellulose, glucans, and energy and did not affect protein digestibility. The present work showed the high potential of BSG to produce an added-value functional supplement with high carbohydrases activity and its potential contribution to the circular economy by improving the nutritional value of low-cost and sustainable ingredients that can be included in aquafeeds.

Dietary Phosphorus and Calcium Utilization in Growing Pigs: Requirements and Improvements.

The sustainability of animal production relies on the judicious use of phosphorus (P). Phosphate, the mined source of agricultural phosphorus supplements, is a non-renewable resource, but phosphorus is essential for animal growth, health, and well-being. P must be provided by efficient and sustainable means that minimize the phosphorus footprint of livestock production by developing precise assessment of the bioavailability of dietary P using robust models. About 60% of the phosphorus in an animal's body occurs in bone at a fixed ratio with calcium (Ca) and the rest is found in muscle. The P and Ca requirements must be estimated together; they cannot be dissociated. While precise assessment of P and Ca requirements is important for animal well-being, it can also help to mitigate the environmental effects of pig farming. These strategies refer to multicriteria approaches of modeling, efficient use of the new generations of phytase, depletion and repletion strategies to prime the animal to be more efficient, and finally combining these strategies into a precision feeding model that provides daily tailored diets for individuals. The industry will need to use strategies such as these to ensure a sustainable plant–animal–soil system and an efficient P cycle.

Dietary phosphorus requirement of red swamp crayfish ( Procambarus clarkia )

To evaluate dietary phosphorus requirement of red swamp crayfish (Procambarus clarkia), six diets containing different concentrations phosphorus (2.7, 6.6, 10.5, 14.6, 18.3 and 22.5 g kg−1 diet respectively) were prepared. Each diet was assigned to triplicate of 15 crayfish (initial mean weight: 9.33 ± 0.54 g) for 56 days. The weight gain rate (WGR) significantly increased when dietary phosphorus content increased from 2.7 to 14.6 g kg−1 (p < 0.05), and the feed conversion ratio (FCR) showed an opposite tendency as observed in WGR. As dietary phosphorus level increased, the muscular ash content, the content of calcium and phosphorus in muscle and shell, the inorganic phosphorus concentration in serum, and the protease activities in intestine and hepatopancreas significantly increased (p < 0.05), while the muscular crude lipid content, the lipase activities in intestine and hepatopancreas, the malondialdehyde concentration in hepatopancreas, and the concentrations of total cholesterol, triglyceride and parathyroid hormone in serum significantly decreased (p < 0.05). When crayfish fed diet with phosphorus content from 10.5 to 14.6 g kg−1, the activities of amylase in intestine and hepatopancreas, the activities of catalase in hepatopancreas and the concentration of total antioxidant capacity in hepatopancreas significantly increased (p < 0.05). Broken-line model analysis in terms of the WGR and FCR indicated that optimal dietary phosphorus requirement of crayfish was from 13.9 to 14.3 g kg−1. The signs of phosphorus deficiency for red swamp crayfish were characterized by poor growth, slightly reduced mineralization and increased body lipid deposition.

The effect of dietary phosphorus load and food matrix on postprandial serum phosphate in hemodialysis patients: a pilot study.

Background: Potential dietary strategies for controlling hyperphosphataemia include the use of protein sources with lower phosphorus bioavailability such as pulses and nuts, focus on phosphorus to protein ratios and the avoidance of all phosphate additives. Methods: We conducted a controlled crossover feeding study in 8 haemodialysis (HD) patients to investigate the acute postprandial effect of a modified versus standard low phosphorus diet for one day on serum phosphate, potassium and intact parathyroid levels in prevalent HD patients. Each participant consumed the modified diet on one day and the standard diet on a second day one week apart. The modified diet included beef and less dairy, with a lower phosphorus to protein ratio, as well as plant-based protein, whole grains, pulses and nuts containing phytates which reduces phosphorus bioavailability. Both diets were tailored for each participant to provide 1.1g protein/kg ideal body weight. Participants provided fasting bloods before breakfast, a pre-prandial sample before the lunch time main meal and samples at one-hour intervals for the four hours after the lunch time main meal, for analysis of phosphate, potassium and intact parathyroid hormone (iPTH). Results: At four hours post the lunch time main meal on each study day, individuals on the modified diet had serum phosphate readings 0.30 mmol/l lower than when on the standard diet (p-value = 0.015, 95% confidence interval [CI] -0.57, -0.04). The corresponding change in serum potassium at four hours was a decrease of 0.675 mmol/l (p-value = 0.011, CI -1.25, -0.10). Conclusions: Decreases in both serum phosphate and serum potassium readings on a modified low phosphorus diet encourage further larger studies to explore the possibility of greater food choice and healthier plant-based diets in HD patients. ClinicalTrials.gov registration: NCT04845724 (15/04/2021).