Inorganic Phosphorus Supplementation Research Articles

Profile of metabolic bone disease in extremely low birth weight (ELBW) and very low birth weight (VLBW) neonates

BackgroundMetabolic bone disease (MBD) is an important cause of morbidity in premature, very low birth weight (VLBW), and sick infants and, if left undiagnosed, may lead to structural deformities and spontaneous fractures. The objective of the present study was to study the profile of MBD and to determine the incidence of MBD in infants ≤ 32 weeks/≤ 1250 g at birth.MethodA total of 57 infants ≤ 32 weeks/≤ 1250 g at birth admitted in our NICU from October 2020 to July 2021 were included in the study. These infants underwent screening for MBD at 4 weeks of age. They were stratified into three groups based on their gestation (≤ 28 weeks, 29–30 weeks, 31–32 weeks).ResultsMBD was observed in 100% of extreme preterm babies and 69% of very preterm babies. Overall, the incidence of MBD was 73%. Serum phosphorus level normalized by 42–44 weeks post menstrual age (PMA) across all gestations. Alkaline phosphatase (ALP) levels normalized by 42–44 weeks only in very preterm babies. Seventeen babies ≤ 30 weeks required inorganic phosphorus supplementation in addition to calcium phosphate supplementation in order to correct the MBD. Drugs like caffeine, steroids, and furosemide have significant impact on the development of MBD. The time to reach full feeds with fortification had no statistically significant effect on the incidence of MBD as detected by serum phosphorus level and serum ALP level.ConclusionThe profile outlined in the present study matches the literature reports in many aspects, revealing the importance of characterizing this group for the prognosis and short- and long-term follow-up of newborns with bone metabolic disease.

Inorganic Phosphorus Supplementation in Diets for Farmed Shrimp: Performance and Digestibility of Juvenile Litopenaeus vannamei Fed Monosodium Phosphate, Monoammonium Phosphate, Magnesium Phosphate, and Monocalcium Phosphate

Inorganic phosphates have been used in shrimp feeds to meet phosphorus (P) needs, which may be quantitatively affected by the dietary content of P and other minerals and digestibility. In the present study, performance and digestibility were determined simultaneously in juvenile shrimp (Litopenaeus vannamei) during the grow‐out period (4–23 g ind wt). Shrimps were fed plant‐based diets supplemented with different phosphate ingredients: monosodium phosphate (MSP), monoammonium phosphate (MAP), magnesium phosphate (MgP), and monocalcium phosphate (MCP). The total P level in test diets was 0.79%. MSP supplementation was tested at two dietary calcium:phosphorus ratios to check for possible effects upon shrimp performance and digestibility. A negative control diet was tested with a similar formulation without inorganic phosphate supplementation (0.47% total P). Shrimp was reared in a recirculated clear water tank system (35 ppt salinity, 30°C, 100 individuals/m3) with continuous feeding provided by automatic pellet delivery. Feces were sampled 4–5 times daily throughout the trial. A negative control diet produced P limitation and significantly reduced shrimp performances compared to P‐supplemented diets (P < 0.05). Performance of shrimp‐fed diets containing inorganic phosphates varied for feed conversion rate: 1.24–1.34, survival: 87%–94%, growth: 2.50–2.59 g/week, and no significant difference was found among dietary treatments (P > 0.05). Inorganic P supplementation resulted in significantly higher dry matter, crude protein, ash, and P apparent digestibility coefficient (ADC) compared to P limited negative control diet (P < 0.05). In addition, reduced P ADC (P < 0.05) was checked with higher dietary Ca:P ratio. Phosphorus digestibility in test diets showed significant differences: MSP > MCP, MgP, and MSP + CaCO3; MAP > MSP + CaCO3 (P < 0.05). Digestible P (%) could then be calculated in test diets: MgP (4.77 g Pdig/kg of feed), MSP + CaCO3 (4.81 g Pdig/kg of feed), MCP (5.0 g Pdig/kg of feed), MAP (5.13 g Pdig/kg of feed), and MSP (5.30 g Pdig/kg of feed). Digestible P in phosphate sources (%) could then be calculated: 88.2% MSP, 84.2% MAP, 79% MCP, 72.2% MgP, and 71.8% MSP + CaCO3. Shrimp whole body and exoskeleton phosphorus content also showed significantly higher values in P‐supplemented diets compared to control, regardless of the source tested (P < 0.05). It is concluded that tested phosphates were suitable for feeding juvenile shrimp with MSP, MAP, and MgP diets showing high feed efficiency, while MSP and MAP diets resulted in numerically increased growth, coinciding with numerically higher P digestibility in these phosphates. The elevated P digestibility in the phosphates seems related to their water solubility, though MgP, less soluble and digestible in comparison to MSP and MAP, could also produce good performance.

Effect of a microbial phytase on the growth performance, digestibility and retention in a high plant meal inclusion diet for Atlantic salmon (Salmo salar)

The effect of supplementation of a novel phytase (OptiPhos®; Huvepharma; 750 OTU) to high plant meal inclusion diets for Atlantic salmon (Salmo salar) was assessed. Diets were prepared without phytase, with phytase and with supplemental inorganic phosphorus (MCP). After 61 days significant increases in growth, FCR and protein efficiency were seen in diets supplemented with phytase and with MCP over the negative control (P < 0.05). Addition of phytase significantly increased digestibility of phytate and phosphorus (P) as well as retention over other diets (P < 0.05). Phytase addition significantly decreased faecal P losses while increasing metabolic loss over the negative control (P < 0.05). Addition of MCP showed significant increases in metabolic P loss (P < 0.05). In conclusion, the addition of phytase (OptiPhos®; Huvepharma) resulted in performance improvements comparable to inorganic P dosing, while significantly improving the reduction of effluent wastes from plant meal-based diets.

Performance of phytase-treated fishmeal-free and all-plant protein diets in pond production of market sized hybrid striped bass

We determined if ideal protein (IP) fishmeal-free (FMF) or all-plant protein (PP) diets of available ingredients satisfied production needs of hybrid striped bass (HSB; Morone chrysops x M. saxatilis) grown to market size in ponds managed according to industry practices, and if phytase (Phy) superdosing (20,000 FTUs) could alleviate inorganic phosphorus supplementation. An off-the-shelf commercial feed (COM), an IP control diet containing 16% fishmeal (FM), and four IP test diets with or without phytase superdosing (FMF, FMF + Phy, PP, PP + Phy) were evaluated. Inorganic phosphorus was excluded from phytase treated diets. Hybrid striped bass (averaging 344 g/fish) were stocked (5187 fish/ha) in 4 ponds/diet (0.1 ha) and grown for 5.5 months. Most responses of the five ideal protein diets did not differ significantly (P > 0.1) from the COM. Only net fish yield, weight gain, and FCR of the PP diet were less than those of the COM diet. Fish fed FMF and FMF + Phy diets had higher fish yields, mean weights, and gains than PP and PP + Phy diets. FMF ponds had fewer than expected large (907–1134 g) and more jumbo (>1135 g) fish and FMF + Phy ponds had fewer medium (680–906 g) and more large fish. PP ponds had fewer than expected jumbo fish. The COM diet resulted in larger livers (HSI), lower muscle ratio, but less feed phosphorus added to ponds compared to the FM diet. Absence of differences for other responses confirms the FM diet is a valid proxy for the COM diet. Phytase increased energy and protein retention of the PP diet but not the FMF diet. FM can be replaced with animal and/or plant proteins exclusively without major reductions in hybrid striped bass performance. The PP diet likely requires optimization of Met and branched chain amino acid levels to improve performance. Inorganic phosphorus can be replaced by diet phytase top-coating and judicious inclusion of phytate‑phosphorus without negative impact on HSB production. Phytase superdosing of the FMF and PP diets did not improve production variables but did improve mineral retentions, more so for the PP diet. Phytase superdosing reduced feed phosphorus fed by 60% and pond phosphorus loading by 40% but requires optimization of inclusion levels and economic evaluation before recommendation.

PSII-17 Phosphorus Release Values in Growing Pigs Fed Increments of Optiphos Plus Phytase in Pelleted Diets

Abstract The efficacy of phytase (Pase) from OptiPhos Plus G (Huvepharma, Peachtree City, GA) was compared to inorganic phosphorus (iP) supplements to assess phosphorus equivalency. In 6 replicate 28-d trials, 288 crossbred F2 (Duroc X LR X LW) pigs (20.0 kg, 6 pigs/pen, 48 pens) were randomly assigned to 1 of 8 diets. Pig sex was balanced within pens. Basal corn-soybean meal diets, formulated to exceed nutrient requirements except for Ca and P, supplied 1.30% lysine from the same amounts of all ingredients. Sand was used to balance variable amounts of monocalcium phosphate and limestone. Diets supplied either 0.061, 0.156, or 0.241% iP from monocalcium phosphate or increments of 250, 500, 750, 1,000 and 1,500 FTU/kg from Pase. All diets were pelleted (160°F, 2.5 tons/hr). The modified pellet durability index averaged 92.8% and 88.7% for all diets in each of 2 mixes. Non-linear growth responses to increments of iP and Pase were detected (P &amp;lt; 0.05). Using nonlinear regression models, maximum gain was calculated at 0.23% iP and 1144 FTU/kg Pase (equivalent to 0.31% available P or 0.38% STTD P). Likewise, from non-linear responses (P &amp;lt; 0.05), maximum response in whole-body bone mineral content (WBBMC) from analysis of dual energy x-ray absorptiometry scans were calculated at 1227 FTU/kg Pase. The maximum Pase response for WBBMC was below expectations and raised concerns for potential Ca limitations in diets at higher Pase supplements. Only linear WBBMC responses (P &amp;lt; 0.001) to iP levels were detected. Responses across iP and Pase treatments for femur bone mineral content reflected the same conclusions as responses to WBBMC. As growth responses to iP and Pase diets were non-linear, simple conversions of phytase activity to phosphorus release was not straight-forward. However, non-linear equations can predict economic values of target levels as a function of ingredient costs.

The influence of phosphorus source and the nature of nitrogen substrate on the biomass production and lipid accumulation in oleaginous Mucoromycota fungi

Oleaginous filamentous fungi grown under the nitrogen limitation, accumulate high amounts of lipids in the form of triacylglycerides (TAGs) with fatty acid profiles similar to plant and fish oils. In this study, we investigate the effect of six phosphorus source concentrations combined with two types of nitrogen substrate (yeast extract and ammonium sulphate), on the biomass formation, lipid production, and fatty acid profile for nine oleaginous Mucoromycota fungi. The analysis of fatty acid profiles was performed by gas chromatography with flame ionization detector (GC-FID) and the lipid yield was estimated gravimetrically. Yeast extract could be used as both nitrogen and phosphorus source, without additional inorganic phosphorus supplementation. The use of inorganic nitrogen source (ammonium sulphate) requires strain-specific optimization of phosphorus source amount to obtain optimal lipid production regarding quantity and fatty acid profiles. Lipid production was decreased in ammonium sulphate-based media when phosphorus source was limited in all strains except for Rhizopus stolonifer. High phosphorus source concentration inhibited the growth of Mortierella fungi. The biomass (22 g/L) and lipid (14 g/L) yield of Umbelopsis vinacea was the highest among all the tested strains.Key points• The strain specific P requirements of Mucoromycota depend on the nature of N source.• Yeast extract leads to consistent biomass and lipid yield and fatty acids profiles.• Umbelopsis vinacea showed the highest biomass (22 g/L) and lipid (14 g/L) yield.• High P source amounts inhibit the growth of Mortierella fungi.

Effect of supplementation of phytase to diets low in inorganic phosphorus on growth performance and mineralization of broilers

There has been discussion regarding microbial phytase replacing inorganic phosphorus (P) supplementation in broiler diets. Therefore, an experiment was conducted to examine the effect of phytase supplementation on diets low in inorganic P. Ross 308 broilers (n = 288) were fed one of 6 experimental diets in 4 phases. The control diet had 16.20, 10.90, 9.40, and 6.10g/kg inorganic P in the Starter, Grower 1, Grower 2 and Finisher phase respectively. The remaining diets had 10.50g/kg inorganic P in the Starter phase. Two of the diets had graded reductions in inorganic P of 5.10, 3.60, and 0.60g/kg or 2.00, 0.50, and 0.60g/kg for the Grower 1, Grower 2 and Finisher phase respectively, plus 500 FTU phytase. Three of the diets had inorganic P levels of 0.40, 0.50, and 0.60g/kg for the Grower 1, Grower 2 and Finisher diets respectively and either 500, 750, or 1,000 FTU phytase. Broiler performance was analyzed at d 10, 20, 26, and 35. On d 35, ileal calcium (Ca) and P digestibility and tibia bone strength, mineralization, and mineral content were analyzed. There were no significant differences between the control diet and diet containing 1,000 FTU phytase and low inorganic P in the grower or finisher diets based on bird performance, tibia strength, and Ca and P digestibility. Birds fed the control diet had significantly higher BWG (P = 0.001), bone strength (P < 0.001) and ash content (P < 0.001) compared to birds fed the diets with 500 FTU or 750 FTU phytase and low inorganic P in the grower and finisher stages. This may be due to incomplete dephosphorylation of the inositol ring of phytate with these doses of phytase, but with 1,000 FTU phytase there was almost complete phosphate hydrolysis of each phytate. This study showed that relying on phytase alone to ensure full supply of P in broiler diets is viable in finisher diets but is not recommended in grower diets unless phytase is supplied at doses of 1,000 FTU or greater.

Modulation of ruminal fermentation profile and microbial abundance in cows fed diets treated with lactic acid, without or with inorganic phosphorus supplementation

This study evaluated the effects of lactic acid (LA) treatment of concentrates without or with inorganic P supplementation on ruminal fermentation profile and microbial abundances in non-lactating cows. Six rumen-fistulated Holstein cows were assigned to a double 3×3 Latin square design with 3 experimental periods. Each period lasted 14 d, whereby the measurements were performed during the last 2days. Cows were fed 3 diets containing untreated control concentrate supplemented with inorganic P, and two LA-treated concentrates, either without (LA−P) or with (LA+P) the inorganic P supplementation. The concentrate mixtures of the LA diets were soaked in 5% LA for 24h before feeding, whereas the concentrate of control diet was not. All diets were offered as a total mixed ration (forage to concentrate ratio of 53:47). Ruminal pH, ammonia and short-chain fatty acid (SCFA) concentrations were determined in free ruminal liquid (FRL) and particle associated ruminal liquid (PARL) that was collected at 0, 2, 4, 8, and 12h post-morning feeding. Target ruminal microbes in FRL and rumen solid digesta collected at 2h post-feeding were analyzed using quantitative PCR. Cows consumed on average 17±1.0kg DM/d (mean±SEM), irrespective of the treatment. The concentration of total SCFA in FRL was increased by LA treatment (P<0.001) without affecting the pH. Irrespective of P supplementation, feeding of LA-treated diets shifted SCFA profile towards more propionate in the FRL and PARL. The LA−P diet lowered ammonia concentration compared to the other diets (P<0.05). The LA−P diet also reduced the fungal gene copies in solid digesta by 7.6% compared to the LA+P diet (P<0.05). The total bacterial abundance in both ruminal fractions was not affected by diet; however, compared to the control, LA treatment enhanced (P<0.05) the relative abundance of genus Prevotella in FRL (18%) and in solid digesta (27%). In contrast, the same treatment decreased the abundances of Clostridium cluster IV (23%) in FRL and Selenomonas ruminantium group (30%) in solid digesta (P<0.05). Abundances of fibrolytic microbes correlated with acetate and butyrate only in the rumen solid digesta. In conclusion, the LA treatment of concentrates caused major bacterial shifts, an increase of ruminal fermentation output, and enhancement of propionate fermentation without affecting ruminal pH. The lack of inorganic P supplementation did not impair rumen variables measured, but additional P supply and LA treatment of concentrates beneficially affected ruminal fungi. Lowered ruminal ammonia and branched-chain SCFA concentrations by the LA−P diet suggest lowered protein breakdown in the rumen by this treatment.

Metabolic responses, performance, and reticuloruminal pH of early-lactating cows fed concentrates treated with lactic acid, with or without inorganic phosphorus supplementation

Recent data indicate beneficial effects of treating grains with lactic acid (LA) in alleviating the need for inorganic phosphorus supplementation during ruminal fermentation in vitro. The aim of this study was to evaluate the effects of feeding concentrates treated with LA with or without inorganic phosphorus supplementation on feed intake, performance, blood variables, and reticuloruminal pH in dairy cows. A total of 16 early-lactating cows (12 Simmental and 4 Brown Swiss) were included in this study from d 1 until d 37 postpartum. Cows were fed 3 total mixed rations differing in supplementation of inorganic phosphorus and treatment of concentrates. The control (CON) and LA (+P) diets included a concentrate mixture containing 0.8% monocalcium phosphate, and the LA (−P) diet contained no inorganic phosphorus source. The concentrates of the LA (+P) and LA (−P) diets were treated with 5% LA for 24h before feeding, and the concentrate of the CON diet was not treated. Dry matter intake and milk yield were recorded daily, and milk composition and blood variables were determined on several occasions during the trial. Reticuloruminal pH was measured using indwelling sensors that allowed for continuous measurement during the experimental period. Data showed depressed dry matter intake in cows receiving LA-treated concentrates, but milk yield, body weight, and body weight changes remained similar among treatment groups. Cows receiving the LA-treated diets had lower concentrations of serum nonesterified fatty acids, cholesterol, and insulin, and they tended to have higher serum phosphorus levels. On the other hand, reticuloruminal pH was lower and duration of the pH being <6.0 was longer in cows in the LA-treated groups. Aspartate aminotransferase, gamma-glutamyltransferase, and concentrations of bilirubin and bile acids were lower in the LA (−P) group. Taken together, the 5% LA-treated diet without inorganic phosphorus supplementation did not exert any negative effects on performance. The observed beneficial effects on blood metabolites related to lipid metabolism, insulin sensitivity, and liver variables, as well as the tendency for greater systemic phosphorus circulation, suggest that diets including concentrates treated with 5% LA may allow for savings of inorganic phosphorus supplementation in dairy cows. Treatment with 5% LA enhanced cows’ risk of developing subacute rumen acidosis, although this condition showed no adverse effects with respect to liver variables and the inflammatory response.

Optimum Dietary Ca/P Ratio and Phytase for Growth and Bone Mineralization in Juvenile Clarias gariepinus Fed Soya Bean-Based Diet

The research investigated the interactive effect of five phytase graded levels of 0 FTU/g (P0), 250 FTU/g (P1), 500 FTU/g (P2), 750 FTU/g (P3), 1000 FTU/g (P4) and four graded levels of roasted soya bean substitution at 25%, 50%, 75% and 100% in place of fish meal, respectively. All basal diets contained 0.20% calcium without added inorganic phosphorus, wheat and amino acids supplements so that the phosphorus, calcium, and Ca/P ratios of the five (5) were: S0 (1.31%, 1.85%, and 1.41), S1 (1.15%, 1.64%, and 1.43), S2 (1.01%, 1.28%, and 1.27), S3 (0.75%, 0.99%, and 1.30), and S4 (0.43%, 0.68%, and 1.59). 1092 fish of average weight 11.55 ± 0.2 g were randomly allocated to all experimental diet and fed 3% body for 84 days. There was no significant difference in final weight, weight gain and FCR S3P1 and S0P0 (P>0.05). Fish fed low phosphorus diet (100% soya bean) showed reduced total weight and weight gain compared to high (0%, 25%, 50%) and medium phosphorus diet (75%) with phytase addition (P 0.05), and PER (r=-0.210, P>0.05). Ca/P of S3P1 (1.41 ± 0.02) was not different from S0P0 (1.41 ± 0.01). Bone phosphorus, calcium and zinc were higher in 250 FTU/g compared to 0 FTU/g, 500 FTU/g, 750 FTU/g and 1000 FTU/g. In conclusion, Phytase improved growth performance (r=0.05) of juvenile Clarias gariepinus with optimum at 250 FTU/g; however, Ca/P affected performance (r=-0.431) and should range between 1.41-1.46 for optimum phytase activity.

Increasing biomass of winter wheat using sorghum biochars

Biochar is a black solid formed by pyrolysis of biomass such as crop residues. Biochar could be used for soil fertilization, carbon sequestration, and improvement of soil structure. Here, we tested the effect of sorghum biochars on winter wheat, with or without supplemental inorganic phosphorus, in a greenhouse. The application rate for sorghum residues and sorghum biochars based on a yield goal of 200 bushels ha−1 was 13 Mg ha−1. Inorganic phosphorus was added at the rate of 40 kg P ha−1. Results show that addition of sorghum biochars increased the total biomass of winter wheat grown by about 31 % over the control plants. Addition of supplemental inorganic phosphorus did not increase the total biomass. Our findings suggest that the pyrolitic transformation of sorghum residues into sorghum biochars is a better strategy for both environmental and crop productivity improvement in the Coastal Plains region.

Dietary Supplementation of Lipid and Inorganic Phosphorus to Develop Environment-Friendly Feed for Young Red Sea Bream, &lt;i&gt;Pagrus major&lt;/i&gt;

An experiment was conducted to investigate the effects of dietary lipid and inorganic phosphorus supplementation on growth, retention and loading of phosphorus and nitrogen in young red sea bream. Two levels of lipid (190 and 250 g/kg) and two levels of phosphorus (14 and 19 g/kg) in the dry diets were tested. Four practical diets were formulated and coded as L0P0, L0P1, L1P0 and L1P1, respectively. Diet L0P0 was the fish meal-based (50% fish meal) control diet without addition of lipid and phosphorus (P). Diet L0P1 was supplementation of 2 % mono sodium phosphate to the L0P0 for providing 0.5 % P. Diet L1P0 was supplemented with 5% soybean oil and L1P1 was formulated with the addition of 5% soybean oil and 0.5% P. All diets were fed four times a day until satiation to duplicate groups of 25 fish (mean initial body weight 70.0 ± 1.3g) during 12-week feeding trial. At the conclusion of the experiment, growth and feed performance were lowest in the fish fed control diet, and significantly (P&lt;0.05) improved by supplementing with P. On the other hand, lipid supplementation did not show any statistical difference among the dietary groups. The P and nitrogen (N) retention values for P supplemented diets were significantly (P&lt;0.01) greater and reduced (P&lt;0.01) both N and P excretion. This study demonstrated that, diet with the addition of inorganic P significantly improved fish growth, FCR, nutrient retention, and reduced both N and P loading while no addition of lipid is necessary.DOI: http://dx.doi.org/10.3329/pa.v21i1-2.16761 Progress. Agric. 21(1 &amp; 2): 131 - 139, 2010

INTERACTION BETWEEN DIETARY MINERAL AND PHYTASE ON BIOLOGICAL PERFORMANCES OF JAPANESE FLOUNDER, Paralichthys olivaceus. PART I. GROWTH, FEED INTAKE, AND WHOLE BODY MINERAL CONTENT

In order to determine the effect of dietary calcium (Ca), inorganic phosphorus (IP), and phytase (P) supplementation in marine fish, a 2 x 2 x 2 factorial design was arranged to observe the interrelationship between dietary Ca and IP with the presence of dietary phytase. Two levels of dietary Ca at 0% and 0.2% combined with either 0% or 0.25% of dietary IP and either with 0 and 2,000 FTU phytase/kg diet, respectively to formulate eight experimental diets. SPI-based diet was used as basal diet and the sources of Ca, IP, and phytase were similar to those used in the previous experiment. Juvenile Japanese flounder with initial body weight around 0.6 g was fed the test diets. After 30 days of feeding trial, the results showed that both dietary IP and phytase, but not dietary Ca significantly enhanced the growth and feed intake. The highest growth was achieved in fish fed a diet containing the Ca, IP, and phytase supplement among groups. Fish fed diet without the three dietary supplements had the lowest SGR and did not significantly improve by supplementing dietary Ca. Feed intake (FI) and was significantly influenced by dietary IP and phytase, not dietary Ca while feed conversion ratio (FCR) was significantly affected by all dietary treatments. Interaction effect was detected between dietary Ca and IP, between dietary IP and P on FCR. Total phosphorus content in whole body was significantly increased by supplementing all dietary treatments which was highest in fish fed 0.25 IP/0.2 Ca/P. Significant interaction was observed between dietary IP and P on this parameter. Whole body Ca content was significantly improved by either dietary IP or Ca and not dietary P. As conclusion even without inorganic Ca supplement, dietary IP at level of 0.25% or 2,000 FTU phytase/kg diet could enhance growth and FI of fish as well as whole body phosphorus content of juvenile Japanese flounder when diet basal contained organic Ca around 1.2%.

Intestinal phytase activity in chickens (Gallus Domesticus)

The objective of the study was to adapt an assay and determine the effect of innate and dietary factors on intestinal phytase activity (IPA). The release of phosphorus, when an extract of intestinal mucosa was incubated with phytate as substrate, was used to measure phytase activity. Maximum IPA was detected between pH 5.6 and 6.2, and it was very low and non-detectable at pH 7.0-7.4. Activity was dependent on the presence of Zn2+ and Mg2+, and IPA was inhibited by a commercial phosphatase inhibitor cocktail but not by L-phenylalanine, an inhibitor of alkaline phosphatase. The activity in the proximal portion of the duodenal loop was higher than in the distal portion. Newly hatched chicks exhibited IPA and neither age (1 to 8 weeks) nor gender had an effect on IPA in broiler chickens. However, a gender effect was evident in a layer strain; females had 94.7% higher IPA than males. Lowering the total phosphorus level of the broiler starter diet increased IPA. During the growing period, IPA was almost twice as high when the diet contained no supplemental inorganic Phosphorus. High dietary iron depressed IPA in fast- and slow-growing meat strains. The results indicate that phytase activity is present along the gastro-intestinal tract of chickens and that intestinal pH and nutrient composition are important modulators of intestinal phytase activity and phytate phosphorus utilization. Key words: Intestinal phytase activity (IPA), inhibition, broilers, layers, phytate phosphorus.

Dietary inorganic phosphorus or microbial phytase supplementation improves growth, nutrient utilization and phosphorus mineralization of juvenile red sea bream, Pagrus major, fed soybean-based diets

A 2 × 3 factorial design with triplicates examined the interaction between dietary inorganic phosphorus (IP) and phytase on growth, mineral utilization and phosphorus (P) mineralization in juvenile red sea bream. The treatments were three levels of dietary IP supplementation at 0, 2.5 and 5 g kg−1, either without or with phytase supplementation [2000 FTU kg−1; phytase unit is defined as the amount of enzyme activity which liberates 1 micromol of inorganic phosphorus per minute at pH 5.5 and 37 °C at a substrate concentration (sodium phytate) of 5.1 mmol L−1]. Juvenile red sea bream (IBW = 1.3 g ± 0.1) were stocked twelve fish per tank and fed for 50 days. Growth and feed efficiency were significantly (P < 0.05) enhanced by both dietary P and phytase supplementation. Feed intake and survival rate were not significantly affected by the dietary treatments. Both dietary IP and phytase supplementation significantly increased plasma IP and Mg levels. Concentration of vertebral mineral and scale P was significantly increased by both dietary treatments. A skeletal malformation syndrome of scoliosis occurred in fish fed both non-IP and non-phytase supplemented diet. Interaction between main dietary effects was detected for vertebral Zn, scale P and whole-body ash and Mg content. With regard to growth and other examined productivity traits, phosphorus requirement of juvenile red sea bream can be met if supplemented with 2000 FTU phytase kg−1 or in the absence of phytase, by dietary inclusion of 2.5–5 g kg−1 of IP.

DESEMPENHO E AVALIAÇÃO DA CARCAÇA EM SUÍNOS ALIMENTADOS COM RAÇÕES DE TERMINAÇÃO COM FITASE ASSOCIADA À RETIRADA DE MICROMINERAIS, VITAMINAS E FÓSFORO INORGÂNICO

The experiment aimed to evaluate the effect of phytase enzyme in rations for swine at the finishing phase without the use of mineral-vitamin supplement and with reduced levels of inorganic phosphorus on performance and carcass characteristics, ashes and mineral percentage in the bones and economic viability. Twenty-four hybrid females with starter weight of 66 ± 1.4 kg and final weight of 106 ± 1.8 kg were housed for 38 days in 24 stalls and allotted in a completely randomized experimental design with six treatments and four replications of two animals each. The following treatments were used: T1 –­­ basal feed; T2 – basal feed without micromineral-vitamin supplement; T3 – basal feed with phytase and without micromineral-vitamin supplement; T4 – basal feed with phytase, without micromineral-vitamin supplement and without 1/3 of inorganic phosphorus; T5 – basal feed with phytase, without micromineral-vitamin supplement ans without 2/3 of inorganic phosphorus; and T6 – basal feed with phytase, without micromineral vitamin supplement and without inorganic phosphorus supplementation. The withdrawal of the micromineral-vitamin supplemet, the reduction of inorganic phosphorus level and the addition of phytase enzyme did not affect (P>0.05) the carcass characteristics, but they reduced (P<0.05) feed intake and weight gain, and showed worse feed conversion. Likewise, reduction of inorganic phosphorus levels and phytase addition did not improve economic efficiency when compared to basal feed. KEYWORDS: Enzyme, finishing phase, pig, ration, weight gain.

Dietary sevelamer hydrochloride prevents dietary 1 alpha‐hydroxycholecalciferol (1 alpha‐OH D3)‐induced increases in plasma phosphorus

A study on the mechanism by which sevelamer hydrochloride (Sev), a polymeric phosphate binder, lowers plasma phosphorus in end‐stage renal failure patients was conducted using a day‐old chick model. Three pens of 5 broiler‐type male chicks/treatment were fed a diet marginally deficient in phosphorus (diet 1, P deficient), diet 1 plus adequate inorganic phosphorus (diet 2), diet 1 plus 20ug/Kg 1 alpha‐OH D3 (diet 3), diet 2 plus 2 g/Kg diet Sev, or diet 3 plus 2g/Kg diet Sev. After three weeks, all chicks were weighed, bled (to determine plasma phosphorus), and the right tibiotarsus was collected for determination of dry fat‐free bone ash. Addition of phosphorus or 1 alpha‐OH D3 to the P deficient diet (diet 1) increased weight, bone ash, and plasma phosphorus as compared to chicks fed a phosphorus deficient diet (p&lt;0.001). Addition of Sev was ineffective at reducing body weight, plasma phosphorus or bone ash when phosphorus was made adequate using inorganic phosphorous, but did decrease these variables when added to the diet supplemented with 1 alpha‐OH D3 (p&lt;0.001). These data showed that Sev, at the dose used, was not able to counteract improved phosphorus status associated with inorganic phosphorus supplementation but was effective in preventing improved phosphorus status resulting from the addition of 1 alpha‐OH D3. This work was supported by the Wisconsin Alumni Research Foundation.

Survival And Growth Responses Of Frys Of The African Catfish Hybrid (&lt;i&gt;Clarias gariepinus X Heterobranchus bidorsalis&lt;/i&gt;) To Soluble Dietary Supplements Of Inorganic Phosphorus.

Four (4) isonitrogenous experimental diets with 38.00% crude protein were formulated and replicated three times to include four supplemental inorganic phosphorus (H3PO4) levels of 0.20%, 0.80%, 1.00 and 1.20%. The control experiment (replicated three times) consisted of diets with non-inorganic phosphorus. The dietary treatments were fed to 4-weeks old hybrid of Clarias gariepinus × Heterobranchus bidorsalis (mean weight, 2.10 ± 0.14 g) at 5% body weight per day for 42 days. The soluble reactive concentration level of the inorganic phosphorus (SRP) in experimental water was investigated, the growth response and survival of the fish evaluated. The results indicated that the water treated with the control diet (0.03 mg/l) had a higher concentration of SRP than any of the H3PO4-supplemented diet. The range values of SRP in water with dietary 0.60% and 0.80% P-supplementation did not vary significantly (P > 0.05). There were significant differences (P < 0.05) in the range values of SRP of water treated with 1.00%, 1.20% and 0.00% P (control) diets, even though the values for the mean weight gain (MWG) and food conversion ratio (FCR) were not significantly different (P > 0.005). The phosphorus gain/loss (PGL) values of fish were only significantly different (P < 0.05) between the 0.80%, 1.20% and the control diets. The non-significant difference (P > 0.05) of the PGL of fish when 0.60% P and 1.00% diets were applied apparently corresponded with non-significant difference (P > 0.05) recorded for the SRP of water treated with 0.60% and 0.80% P diets. Keywords:Inorganic phosphorus, soluble reactive concentration, supplemental diets.Journal of Technology and Education in Nigeria Vol. 10 (1) 2005: pp. 11-19

Phosphorus bioavailability in diets for growing horses

A study of phosphorus (P) metabolism was carried out using 12 month old Brasileiro de Hipismo breed of horses to determine the P bioavailability available from feeds commonly fed to horses in Brazil. Five different diets were formulated to contain approximately equivalent levels of crude protein and digestible energy, as well as to supply at least 22 g P/horse/day (NRC, 1989). All 5 diets contained 40% Bermuda coastal hay plus 60% concentrate. The 5 different concentrates contained: C1 (corn + cottonseed meal) C2 (corn grain + soybean meal) C3 (corn + sugarcane yeast), C4 (oat + cottonseed meal), and C5 (oat + soybean meal). The radioisotope 32P was injected with 30 MB. Blood, feces and urine were collected for 7 days to evaluate endogenous fecal P and true absorption. Analysis of variance of P intake showed differences due to dietary effects ( P < 0.05). Concentrate C3 had the lowest intake (79.68 mg/ kg BW). All of the diets produced positive P retention. Absolute values for P concentrations in plasma, urine, feces and endogenous feces did not vary between diets. Values for endogenous fecal P were independent of the level of P intake, so the correlation between P intake and P endogenous was not significant. P bioavailability values were 50.75; 40.98; 43.50; 51.03 and 57.68% for diets C1 through C5, respectively. However, differences in P bioavailability were found ( P < 0.05) between diets. Diets C2 and C3 had lower P bioavailability than the other diets. The P bioavailability of all dietary treatments in this study exceeded NRC (1989) postulations of 35% true P absorption in diets not supplemented with inorganic P. The results of this study indicate that inorganic P supplementation is not needed for growing yearlings fed common Brazilian feeds. Considering the high cost of P supplementation and the risk of environmental P contamination, inorganic phosphorus supplementation for growing yearlings may not be required.

Environmental assessment of Ronozyme® P5000 CT phytase as an alternative to inorganic phosphate supplementation to pig feed used in intensive pig production

Goal, Scope and Background. Ronozyme® P5000 CT is an industrially produced enzyme product (phytase) which is able to degrade naturally occurring phytate in animal feed and release the phytate's content of phosphorus for pig's growth. Ronozyme P5000 CT (hereafter called Ronozyme Phytase) can be used as an alternative to inorganic phosphorus supplementation to feed and the study addresses the environmental implications of substituting inorganic phosphorus with Ronozyme Phytase in intensive pig production in Denmark. Methods. Life cycle assessment is used as an analytical tool, and modelling of the two considered systems is facilitated in SimaPro 6.0 software. The study addresses changes induced by switching from the one alternative to the other, and all significant processes influenced by the change are included in the study. Results and Conclusions. Application of Ronozyme Phytase in intensive pig production is justified by major advantages in terms of avoided contributions to global warming, acidification, photochemical ozone formation and particularly nutrient enrichment and by significant energy savings and particularly phosphate savings. A single trade-off in terms of agricultural land use for enzyme production is small and unimportant unless use of agricultural land is given very large relative weight. Recommendations and Perspectives. Hundreds of enzyme products are commercially available on the market today, each with a range of different applications. There are several indications that enzymes like Ronozyme Phytase can play an important role in a transition to a more sustainable society, and more focus should be addressed to the evolving enzyme technology in environmental research.