Levels Of Monocalcium Phosphate Research Articles

From sewage sludge ash to a recycled feed phosphate – digestibility of precipitated calcium phosphate in broiler chickens and growing pigs

Today, EU is largely (∼92%) dependent on the import of phosphates as most mines are located outside Europe. Because of the limited availability, phosphorus (P) is included on the list of Critical Raw Materials. Precipitated calcium phosphate (PCP) recovered from sewage sludge ash is a novel and sustainable option to replace mined P as raw material in feed phosphates, e.g. monocalcium phosphate (MCP) or dicalcium phosphate, but the digestibility has not yet been tested in vivo. The aim was therefore to determine PCP and MCP apparent ileal digestibility (AID) of P in broiler chickens and apparent (ATTD) and true (TTTD) total tract digestibility of P in growing pigs. A chicken study comprised 240 Ross 308 chickens that were housed in groups of eight from day 21 to day 28. Five diets were used, a basal diet and two test diets, which contributed either 0.075% (low) or 0.150% (high) additional P for each of the test sources (MCP and PCP). The basal and test diets were composed to achieve increasing levels of P and AID was calculated with regression analysis. In the pig study, eight individually housed pigs were used in a change-over study with two experimental periods. The pigs were fed a basal P-free diet in a preperiod to be able to estimate endogenous P losses and then two different diets in two periods using a change-over design, where MCP and PCP were the only P source, providing in total 0.33 (basal diet), 4.42 (MCP) and 3.53 (PCP) g kg-1P, respectively. The AID of P in PCP and MCP for chickens was 58.4 and 75.1% (P = 0.166). The ATTD and TTTD of P in PCP for pigs were 58.4 and 67.2%, respectively, which was lower (P < 0.001) than the corresponding values for MCP (82.1 and 89.1%), respectively. The digestibility of calcium (Ca) did not differ in the chicken diets with high inclusion levels of PCP and MCP (54.7 and 55.3%, respectively, P = 0.535), but was lower for PCP than MCP in the pig study (57.8 and 70.8% respectively, P = 0.001). In conclusion, the digestibility of P in PCP for chickens did not differ from conventional MCP, whereas for pigs, it was lower, but could be a viable alternative to other common sources of P.

Novel self-bonding composites: resin-dentin interfacial chemistry

Introduction: The biggest shortcoming of adhesive restorations is their susceptibility to bond degradation, when the substrate is dentin [1]. Since the quality of the resin-dentin interface relies mainly on its nanostructure [2], it is important to study the hybridization process in self-adhesive composites. Knowledge of the resin-dentin interface chemistry will provide insight into bonding, and possible susceptibility towards degradation [3]. Materials and methods: 9 primary teeth, obtained with informed consent from the Eastman Dental Hospital, previously approved by the EDI/EDH Joint Research & Ethics Committee were sectioned to obtain flat dentin surfaces, polished with 500 SiC grit paper and etched before material placement. The teeth were randomly divided (n = 3) between 3 materials - Activa ™ BioActive Restorative and 2 experimental composites. The experimental flowable composites had different levels of monocalcium phosphate (MCPM) and antibacterial polylysine (PLS) powders added to the filler phase. Restored teeth were stored in DI water for 24 h and vertically sectioned to obtain slabs perpendicular to the interface. Raman spectroscopy (Horiba Jobin Yvon, Paris, France) was used to research the chemistry of the resin-dentin interface. Three different lines were analysed in each sample to ensure reproducibility. Means corresponding to resin and dentin peaks were calculated and plotted using Microsoft Excel Tools (v15.30, Redmond, Washington, USA). FE-SEM (Phillip XL-30, Eindhoven, The Netherlands) was used to gather microstructural imaging of the interface. Results: Differences in chemical composition of the resin-dentin interface was found within interfacial regions ranging from 4 to 8 μm deep. Spectra obtained in mineralized dentin confirmed material diffusion and penetration in all cases. Doubling the hydrophilic additives in experimental composites, increased the resin infiltration depth by almost two-fold and affected the apatite to collagen ratio variation within the interface. SEM imaging confirmed resin tag formation, with all materials. Discussion and conclusions: No distinct hybrid layer was found at the interfaces, which is in accordance with previous studies [4,5]. However, resin infiltration was observable with all materials, providing evidence of envelopment and micromechanical interlocking. A gradual transition from dentin to pure material confirmed the presence of an interdiffusion zone [6] which was enhanced with increased hydrophilic additives. These results confirm micromechanical interlocking with dentin is achieved in both the experimental and commercial materials.

True digestible phosphorus requirement for forty- to eighty-kilogram pigs.

The objective of this study was to determine the true digestible P requirement of 40- to 60-kg (Exp. 1) and 60- to 80-kg (Exp. 2) pigs by broken-line analysis of growth performance data using 6 levels of true digestible P. In each 3-wk experiment, 108 barrows and gilts were used, and 6 levels of monocalcium phosphate were added to a corn-soybean meal-based diet to establish 6 graded levels of true total tract digestible P ranging from 1.26 to 3.98 g/kg of diet in Exp. 1 or from 1.21 to 3.31 g/kg in Exp. 2. The true digestible P content was calculated using true total tract digestibility of 40.53%, 35.96%, and 84.31% for P in corn, soybean meal, and monocalcium phosphate, respectively. Limestone was added accordingly to maintain a constant Ca level across all diets of each experiment. The results of Exp. 1 showed that with graded supplementation of monocalcium phosphate, ADG linearly increased ( < 0.001) in wk 1 and both linearly and quadratically increased ( < 0.01) in wk 2, wk 3, and wk 0 to 3, and G:F linearly improved ( < 0.001) in wk 1, quadratically improved ( < 0.05) in wk 3, and both linearly and quadratically improved ( < 0.05) in wk 2 and wk 0 to 3 ( < 0.05). In Exp. 2, ADG linearly increased ( < 0.001) in wk 1 and both linearly and quadratically increased ( < 0.05) in wk 2, wk 3, and wk 0 to 3, with the graded supplementation of monocalcium phosphate, and G:F linearly improved ( < 0.01) in wk 1 and wk 3 and both linearly and quadratically improved ( < 0.001) in wk 2 and wk 0 to 3. In Exp. 1, the true digestible P requirement was estimated to be 2.66, 2.79, and 2.51 g/kg of diet (884 g DM/kg) for pigs of mixed sex, barrows, and gilts, respectively, on the basis of broken-line regression of ADG data for wk 0 to 3 against 6 true digestible P levels. Using G:F, the P requirement estimate was correspondingly 2.67, 2.51, and 2.93 g/kg of diet. In Exp. 2, the true digestible P requirement was estimated to be 2.29, 2.20, and 2.39 g/kg of diet (884 g DM/kg) using ADG data for wk 0 to 3 as the response variable and to be 2.33, 2.19, and 2.47 g/kg using wk 0 to 3 G:F data for pigs of mixed sex, barrows, and gilts, respectively. In conclusion, the mean TTTD-based P requirement was 2.66 and 2.31 g/kg of diet (884 g DM/kg) for 40- to 60-kg and 60- to 80-kg pigs, respectively.

Effects of Neutral Phytase Supplementation on Biochemical Parameters in Grass Carp, Ctenopharyngodon idellus, and Gibel Carp, Carassius auratus gibelio, Fed Different Levels of Monocalcium Phosphate

AbstractTwo 8‐wk studies were conducted to evaluate the effects of neutral phytase supplementation on hemato‐biochemical status, liver biochemical parameter, and intestinal digestive enzyme activity of grass carp, Ctenopharyngodon idellus, and gibel carp, Carassius auratus gibelio, fed with different levels of monocalcium phosphate (MCP). The control diet was prepared with 2% MCP but without phytase (P2.0). The other three experimental diets were prepared with the addition of 1.5, 1.0, and 0.5% MCP, respectively, when supplemented with 500 U/kg neutral phytase in each diet and designated as PP1.5, PP1.0, and PP0.5, respectively. The results indicated that the serum alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) activities, as well as the albumin (ALB) content were increased in grass carp (P &lt; 0.05) and gibel carp (P &gt; 0.05) fed with phytase‐supplemented diets. Meanwhile, the serum cholesterol, high‐density lipoprotein, and total protein contents of the two species of fish were increased in comparison to the control. In addition, dietary phytase inclusion did not significantly affect hepatic ALP, ALT, and AST activities in the two species of carp fed with different levels of MCP. Amylase activity increased in foregut and hindgut of both species when fed with the phytase‐supplemented diets while lipase activity was reduced in the foregut and hindgut in both fish. This study suggests that neutral phytase supplementation increases serum ALP, ALT, and AST activities but does not notably affect these enzyme activities in the liver of the two species of carp when fed different levels of MCP. On the other hand, amylase activity increased while lipase activity was reduced in the intestine of the species of carp fed with phytase‐supplemented diets.

Influence of dietary phosphorus concentration on the digestibility of phosphorus in monocalcium phosphate by growing pigs

An experiment was conducted to test the hypothesis that the dietary inclusion rate of P does not influence the digestibility of P. The experiment was conducted at 4 experiment stations where the same protocol was followed. A total of 60 growing pigs (initial BW: 22.22 +/- 2.13 kg) were allotted to 6 dietary treatments with 10 replications per treatment. All pigs were placed in metabolism cages that allowed for the total, but separate, collection of urine and fecal materials. Six diets were formulated. The basal diet was based on corn (54.2%), soybean meal (20%), and cornstarch. No inorganic P was used, and the total concentration of P in the basal diet was calculated to be 0.29%. Five additional diets were formulated by adding monocalcium phosphate (MCP) in increments of 0.34% to the basal diet and thereby creating diets that were calculated to contain 0.36, 0.43, 0.50, 0.57, and 0.64% total P, respectively. Ground limestone was also added to these diets to maintain a calculated Ca:P ratio of 1.2:1. The balances of Ca and P and the apparent total tract digestibility (ATTD) of Ca and P were calculated for each diet. The contribution of P from the basal diet was then subtracted from the MCP-containing diets to calculate the balance and ATTD for P in MCP. Results of the experiment showed that the absorption and retention of both Ca and P increased (linear, P < 0.001) with increasing concentrations of Ca and P in the diet. The ATTD for Ca ranged from 62.3 to 66.8% and was not influenced by the dietary concentration of Ca. However, the ATTD for P increased from 38.4 to 65.2% as increasing levels of MCP were added to the diet (linear, P < 0.001). Increasing P intake from MCP increased (linear, P < 0.001) the excretion of P in the feces, but the quantity of P that was absorbed and retained also increased (linear, P < 0.001) as more P from MCP was added to the diet. When measured as a percentage of P intake, P retention was not influenced by the dietary P concentration. The ATTD for P in MCP ranged from 79.5 to 88.5% and was not affected by the concentration of P in the diet. Results of this experiment demonstrated that the digestibility and absorption of P from MCP are not influenced by the dietary concentration of P.

Effects of pretreatment with microbial phytase on phosphorous utilization and growth performance of Nile tilapia (Oreochromis niloticus)

This study was to assess effects of the pretreatment in all-plant based diets with microbial phytase on phosphorous utilization and growth performance of Nile tilapia (Oreochromis niloticus). Pretreatment trials were conducted using phytase at graded doses to determine the optimal dose of phytase. Available phosphorus (P) levels increased significantly with the increased doses of phytase and the dose of 1000 U kg−1 was most efficient. Based on the pretreatment trials, plant based diets for Nile tilapia were formulated by pretreating with phytase at 1000 U kg−1. Experimental diets were supplemented with graded levels of mono calcium phosphate (MCP) at 25, 18.75, 12.5, 6.25 and 0 g kg −1 diet. In addition, there were three controls: one phytase control, one inorganic P control and one pretreatment control. The results showed that diets pretreated with phytase gave better growth performance, feed conversion ratio and protein efficiency ratio of Nile tilapia compared with the phytase control diet and pretreatment control diet (P < 0.05). There were no significant differences in growth performance of Nile tilapia between the inorganic control diet and phytase pretreated diets supplemented with MCP at 25, 18.75 and 12.5 g kg−1 (P > 0.05), which resulted in significantly better performance than those at 6.25 and 0 g kg−1 (P < 0.05). Dietary interaction effects of phytase were observed for phosphorus retention efficiency and phosphorus load. Apparent digestibility coefficient of P (ADCp) was improved significantly by phytase pretreatment (P < 0.05). No significant difference was detected on ADC of crude protein among all experimental diets (P > 0.05).

Effects of a microbial phytase on the utilization of native phosphorus by carp in a diet based on soybean meal

The effects of a microbial phytase derived from Aspergillus niger (Natuphos®, BASF AG Ludwigshafen, Germany) on growth, body mineralization, phosphorus retention and phosphorus excretion were investigated in common carp (Cyprinus carpio L.). The test diet used in this study was based on soybean meal, fishmeal and wheat starch resulting in a total P content of 7.3 g/kg dry matter (DM). This diet was supplemented with two levels of monocalciumphosphate (MCP) and additionally with phytase at levels of 500 and 1000 U/kg. Triplicate groups of fish (10 carp/tank) of mean initial weight of 40 g were fed at a level of 20 g/kg W0.8 d−1 for 9 wk at a water temperature of 23°C. There was enhanced weight gain, crude ash content and P content in whole body with increasing dietary P content and phytase supplementation, respectively. The P gain was about 4 g/kg gain when P supply was adequate. Supplementation with phytase improved utilization of native plant P and reduced the P excretion/kg gain significantly by 30% compared with MCP-supplemented diets. This effect of the phytase was confirmed by measurements of the total P digestibility.

Effects of a microbial phytase on the utilization of native phosphorus by carp in a diet based on soybean meal

The effects of a microbial phytase derived from Aspergillus niger (Natuphos®, BASF AG Ludwigshafen, Germany) on growth, body mineralization, phosphorus retention and phosphorus excretion were investigated in common carp (Cyprinus carpio L.). The test diet used in this study was based on soybean meal, fishmeal and wheat starch resulting in a total P content of 7.3 g/kg dry matter (DM). This diet was supplemented with two levels of monocalciumphosphate (MCP) and additionally with phytase at levels of 500 and 1000 U/kg. Triplicate groups of fish (10 carp/tank) of mean initial weight of 40 g were fed at a level of 20 g/kg W0.8d−1 for 9 wk at a water temperature of 23°C. There was enhanced weight gain, crude ash content and P content in whole body with increasing dietary P content and phytase supplementation, respectively. The P gain was about 4 g/kg gain when P supply was adequate. Supplementation with phytase improved utilization of native plant P and reduced the P excretion/kg gain significantly by 30% compared with MCP-supplemented diets. This effect of the phytase was confirmed by measurements of the total P digestibility.

Effect of supplementaryAspergillus nigerphytase in diets for piglets on their performance and apparent digestibility of phosphorus

AbstractA total of 384 piglets from a three-way cross Yorkshire ♂ × (Finnish Landrace ♂ × Dutch Landrace♀) ♀ in the live-weight range of 11 to 25 kg were used in a feeding trial. The effect of supplementary microbial phytase from Aspergillus niger var. Van Tieghem on performance (average daily gain (ADG), average daily food intake (ADFI) and food conversion ratio (FCR)) and apparent digestibility of total phosphorus (P), in comparison with a non-supplemented basal diet or a diet supplemented with one or two levels of monocalcium phosphate (MCP), were studied.The piglets were allotted to 12 blocks. Within each block, four experimental diets were offeredad libitumfor a period of 4 weeks i.e. (1) basal diet; (2) basal diet + 1·0 g P, from MCP per kg diet; (3) basal diet + 1·9 g P, from MCP per kg diet; and (4) basal diet + 1450 phytase units (PTU) per kg diet. The diets, with added chromium III oxide as a marker, were cold pelleted without steam at a temperature not above 60°C to avoid a possible inactivation of the phytase. In all diets the ratio calcium: digestible P was intended to be constant.Adding 1450 PTU of Aspergillus niger phytase enhanced the apparent digestibility of P by proportionately 0·216 when compared with diet 1 and by proportionately 0·100 compared with diet 3. In addition, significantly higher ADG and ADFI and better FCR were noted in pigs receiving supplementary microbial phytase than in pigs on any other treatment. The content of digestible P of the diet with added phytase, however, zvas between the two levels of the diets with added MCP.