Levels Of Nonphytate Phosphorus Research Articles

Effects of Phytase Supplementation on the Performance of Broiler Chickens Fed Maize and Wheat Based Diets with Different Levels of Non-Phytate Phosphorus

An experiment was conducted to evaluate the effects of phytase supplementation on the growth performance, nutrients utilization and bone mineralization in broiler chickens. Day-old broiler chicks (n=480) were equally devided into eight treatment groups and fed maize or wheat based isocaloric, isonitrogenous and isocalcium diets having two non phytate phosphorus (NPP) concentrations (0.50% and 0.30%) and two phytase levels (0 and 500 phytase units/kg diet) in a 42 days growth trial. Maize based dietary treatments were MC (NPP 0.50%, MN (NPP 0.30%), MNP (MN+500 units of phytase) and MCP (MC+500 units of phytase), whereas wheat based experimental diets were WC (NPP 0.50%), WN (NPP 0.30%), WNP (WN+500 units of phytase) and WCP (WC+500 units of phytase). The NPP levels were maintained by dicalcium phosphate. Reduction in dietary NPP depressed live weight gain and feed intake and increased feed conversion ratio (FCR). Phytase supplementation to low NPP (0.30%) diets significantly (p 0.05) differences in carcass quality among dietary treatments. The response of phytase was greater in low NPP and maize based diets as compared with high NPP and wheat based diets, respectively. The results show that phytase supplementation to low NPP (0.30%) diets improved the growth performance, relative retention of nutrients (N, Ca and P) and minerals (Ca, P) status of blood and bone in broiler chickens, with a better efficacy in maize based diets. (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 11 : 1642-1649)

The effect of different levels of nonphytate phosphorus with and without phytase on the performance of four strains of laying hens

A 4 x 7 factorial experiment was conducted to determine the effect of different nonphytate phosphorus (NPP) regimens with and without phytase on performance of four strains of laying hens. The strains used were Babcock B300, DeKalb Delta White, Hy-Line W36, and ISA-White. The birds of T1 (Treatment 1), control diet, were fed a diet with 0.45% NPP for the entire experiment (20 to 63 wk of age). The birds of T2 were fed a NPP regimen of 0.25% for Phase 1 (20 to 35 wk of age), 0.2% for Phase 2 (36 to 51 wk of age), and 0.15% for Phase 3 (52 to 63 wk of age). The birds of T3 and T4 were fed a NPP regimen similar to T2 plus 150 or 300 units phytase/kg diet, respectively. The birds of T5 were fed a NPP regimen of 0.2, 0.1, and 0.1% for Phases 1, 2, and 3, respectively. The birds on T6 and T7 were fed a NPP regimen similar to T5, with 150 and 300 units phytase/kg diet, respectively. The criteria for evaluating the effect of dietary treatments were production performance, shell quality, bone ash, and total P excretion. Production traits were drastically reduced and mortality was drastically increased when the birds of T5 were fed a diet with 0.1% NPP during Phase 2 (36 to 51 wk of age). Increasing the NPP level of this treatment from 0.1 to 0.45% during Phase 3 restored the production traits almost to the control level during this phase of the experiment. The NPP regimen of 0.2-0.1-0.1% plus either level of phytase (T6 and T7) restored most of the traits for the entire experiment to the control level (T1), except egg production (EP) and the nonprolapse mortality. Bone ash also remained significantly lower than the control group with this NPP regimen plus the higher level of phytase (T7). Production traits were reduced, and nonprolapse mortality was increased due to the use of a NPP regimen of 0.25-0.2-0.15% without phytase (T2) for the entire experiment. The NPP regimen of 0.25-0.2-0.15% plus the lower level of phytase (T3) restored all the traits except EP to the control level for the entire experiment. The only treatment that maintained performance of all the strains comparable to their controls for the entire experiment was a NPP regimen of 0.25-0.2-0.15% plus the higher level of phytase (T4). Total P excretion of birds fed this NPP regimen was reduced by 55.6% as compared to the control group. The data generally indicated that the higher level of phytase was more effective than the lower level in restoring the performance of birds fed the low-P diets to the control level. Numerous interactions existed among strain x diet for various traits throughout the experiment, indicating the NPP requirement for maintaining production performance may be different among strains.

Effects of microbial phytase supplementation on mineral utilization and serum enzyme activities in broiler chicks fed different levels of phosphorus

An experiment was conducted to study the effect of microbial phytase (Natuphos 500) supplementation in chicks (0 to 6 wk of age) fed different levels of nonphytate phosphorus (nPP) on performance, mineral retention, bone and plasma minerals and serum enzyme activities. Data were analyzed as a 2 × 2 factorial arrangement with two levels of nPP for age periods of 1-d-old to 3 wk (0.35 and 0.22%) and 3 to 6 wk (0.27 and 0.14%) and two levels of phytase (0 and 500 U/kg) in each period. A positive control, adequate in nPP and Ca without phytase, was used. The low-nPP diets caused a negative effect on the performance (P < 0.05) compared to the normalnPP diet. Phytase had a favorable effect on weight gain at 3 wk (P < 0.004) and 6 wk (P < 0.0475) of age and on feed consumption only at 3 wk (P < 0.0106). Feed efficiency was not affected at any stage by addition of phytase. Performances of chicks fed with 0.35 and 0.27% nPP and phytase were comparable to those obtained with the normal-nPP diets. Decreasing nPP content in the diet increased (P < 0.0001) P retention at 3 and 6 wk of age, increased Mg retention at 6 wk, and decreased (P < 0.0001) Ca and Zn retentions at 3 and 6 wk, respectively. Phytase supplementation increased (P < 0.0001) Ca, P, Mg, and Zn retention at 3 and 6 wk of age. Likewise, the decrease in nPP content in the diet caused a significant reduction of tibia ash (P < 0.0023) and Mg content (P < 0.0001) in tibia ash and reduced liver (P < 0.0240), spleen (P < 0.0176), and tibia (P < 0.0001) weights. Similarly, Ca (P < 0.0369) and Zn (P < 0.0181) contents in tibia ash were increased in response to decreasing nPP levels in the diet. Phytase supplementation increased tibia weight (P < 0.0019), tibia ash (P < 0.0021), and Mg (P < 0.0339) and Zn (P < 0.0353) concentrations and reduced (P < 0.0161) the relative liver weight. By decreasing nPP levels in the diet, plasma Ca (P < 0.0001), Mg (P < 0.0001) and Zn (P < 0.0048) concentrations, and alkaline phosphatase (ALP) activity (P < 0.0299) increased, and plasma P content (P < 0.0001), aspartate aminotransferase (AST) activity (P < 0.0001), and total protein (TP) content (P < 0.0050) were reduced. Phytase supplementation increased plasma P level (P < 0.0001) and serum AST activity (P < 0.0049), reduced plasma Ca (P < 0.0001) and Mg (P < 0.0050) contents, and reduced serum alanine aminotransferase (ALT) (P < 0.0048), ALP (P < 0.0001) and lactate dehydrogenase (LDH) (P < 0.0192) activities. Plasma Zn was not affected by phytase supplementation. These results demonstrated that microbial phytase supplementation to low-P diets improved performance; P, Ca, Mg, and Zn use; and tibia weight and relative liver weight in broiler chickens. Likewise, serum AST, ALT, ALP, and LDH activities, as well as TP concentration, were also affected by phytase supplementation.

Influence of Dietary Phosphorus on Performance of Hy-Line W36 Hens

Two experiments were conducted to determine the effect of nonphytate phosphorus (NPP) on hen performance in an environmentally controlled house. In Experiment 1, 21-wk-old Hy-Line W36 hens (n = 1,248) were randomly assigned to 13 dietary treatments (0.1 to 0.7% NPP, at graded increments of 0.05%) for 17 wk. In Experiment 2, 45-wk-old Hy-Line W36 hens (n = 960) were randomly allocated to eight diets in a 2 × 4 factorial arrangement of treatments. Two levels of Ca (3 and 4%) and four levels of NPP (0.1, 0.2, 0.3, and 0.4%) were fed for 8 wk. Feed consumption (FC), egg production (EP), egg weight (EW), egg specific gravity (ESG), bone density (BD), bone mineral content (BMC), bone breaking strength (BBS), BW and mortality were evaluated to determine performance. Results of Experiment 1 indicated that FC, EP, and BW increased as NPP was increased from 0.1 to 0.7% (77 to 588 mg/hen/d). During Week 12, a sharp decrease in FC and EP was observed in hens fed the most deficient level of 0.1% NPP. Egg weight and ESG decreased linearly (P < 0.05) as dietary NPP was increased from 0.1 to 0.7%. However, after 14 wk, ESG decreased (P < 0.05) in hens fed 0.1% NPP. Bone breaking strength was higher (P < 0.05) in hens fed 0.3 to 0.4% NPP, indicating maximum bone quality. Mortality was higher (P < 0.05) in hens fed 0.01% NPP, followed by hens fed 0.15% NPP. In Experiment 2, a pronounced adverse effect of P deficiency was observed on FC and EP within 2 wk compared with 12 wk in Experiment 1. Reduction of NPP to 0.1% reduced BD, BMC, BBS and increased hen mortality (P < 0.05). Reducing dietary Ca from 4 to 3% decreased ESG (P < 0.05). A wide variation in response time to P deficiency indicated that P requirement varied for different performance criteria with age.

The Effects of Phytase Supplementation on the Performance of Broiler Chickens Fed Diets With Different Levels of Non-Phytate Phosphorus

The Effects of Phytase Supplementation on the Performance of Broiler Chickens Fed Diets With Different Levels of Non-Phytate Phosphorus

Reevaluation of Nonphytate Phosphorus Requirement of Growing Pullets with and Without Phytase

An experiment was conducted to re-evaluate the nonphytate phosphorus (NPP) requirement of growing pullets and to determine to what extent this requirement could be reduced by phytase. Six diets in a 3 × 2 factorial design were used. The pullets of the control group (T1) were fed a sequence of 0.4-0.35-0.3% NPP for the age periods of 0 to 6, 6 to 12, and 12 to 18 wk, respectively, according to NRC (1994) recommendation. The NPP level was reduced by an increment of 0.1% in each phase in T2 and T3. The pullets of T4 to T6 were fed similar NPP levels to T1 to T3, respectively, with 300 units phytase/kg diet. From 18 to 30 wk of age, the pullets on all growing regimens were fed a layer diet with 0.4% NPP. Records were maintained for BW and feed intake during the growing period and for egg production during the laying period. Blood and tibia samples were taken at 6, 12, and 18 wk of age for determining plasma P, tibia weight, and tibia ash. Two digestion trials were conducted at Weeks 5 and 18 for determining total P excretion. Body weights at 18 wk and feed intake for the period of 0 to 18 wk were not different from the control for pullets fed the two lower NPP regimens (P > 0.05). Phytase had a favorable effect on BW at 18 wk (P = 0.0539) and feed intake for the period of 0 to 18 wk (P < 0.05). Plasma P was lower for pullets fed the least NPP than for those fed the control NPP regimen only at 6 wk of age (P < 0.05). Bone quality measurements at 6, 12, and 18 wk of age were not different for pullets fed various NPP regimens (P > 0.05). Phytase, for the most part did, not have an effect on plasma P and bone quality (P > 0.05). Total P intake and total P excretion (mg/bird per day) were reduced due to lowering the dietary NPP in both digestion trials (P < 0.05). Phytase did not have an effect on daily total P intake or excretion. Production and specific gravity were not influenced by NPP regimens used during the growing period. Specific gravity for the entire experiment was greater for pullets fed phytase (P < 0.05). The results indicated that the lowest NPP regimen in the absence of phytase was adequate to support performance of pullets, and due to this, it was not possible to determine the effect of phytase in diminishing the P need of growing pullets.

Utilization of High Levels of Meat and Bone Meal in Broiler Diets

Recent sanctions on feeding rendered animal by-products to ruminants may favor feeding high levels of meat and bone meal to broilers. Two samples of meat and bone meal (MBM) - low-ash = 25.87% ash; high-ash = 34.85% ash - were subjected to amino acid and proximate analysis, with digestible amino acid (DAA) and metabolizable energy content calculated. Each source was used to formulate diets in which the minimum DAA was 100% of NRC total amino acid content. The nonphytate phosphorus (NPP) content was increased in increments of 0.10%. Control diets utilized dicalcium phosphate to maintain either a constant 0.45% NPP or to provide levels of NPP recommended by NRC for different age broilers. Inclusion of MBM in broiler diets at levels higher than traditionally used (up to 12.98% of high-ash and 17.76% of low-ash meat and bone meal) had no adverse effects. However, the economics of protein sources as well as supplemental phosphorus sources must be considered. Increasing the level of MBM above that needed to provide adequate levels of NPP may be an environmental concern in some areas of poultry production.

The Potential Value of Morning and Afternoon Feeds for Laying Hens

Two studies were conducted in which variable levels of calcium and phosphorus were fed in morning (04:00 to 12:00 hr) and afternoon (12:00 to 04:00 hr) feeds. In the first study, reducing the afternoon nonphytate phosphorus (NPP) content significantly reduced hen-day egg production, increased feed required to produce an egg, had no effect on egg weight, and reduced shell strength. Calcium effects were related primarily to total Ca intake. There were no Ca effects on egg production or feed utilization; however, morning Ca affected egg weight; afternoon Ca and NPP × Ca interaction affected shell strength.The second study used a different set of morning and afternoon levels of Ca and NPP. Results were similar to the first experiment, indicating that total Ca and NPP intake levels had a greater influence on hen performance than time of day consumed. The hens’ wide range of ovulation times inhibited potential advantages of feeding different diets at different times of the day to accommodate the egg formation cycle. However, simultaneous presentation of diets differing in nutrient control may prove beneficial.

Performance of commercial laying hens fed various phosphorus levels, with and without supplemental phytase

A 17-wk study was conducted to evaluate the effects of supplementing laying hen diets with a commercially produced microbial phytase. Hy-Line W-36 pullets (21 wk of age) were randomly allocated to 1 of 10 diets in a factorial arrangement of five levels of nonphytate phosphorus (0.1 to 0.5% NPP) and two levels of phytase (0 and 300 U/kg feed). Dietary metabolizable energy, protein, and calcium were maintained at 2,816 kcal/kg, 16.6%, and 4%, respectively. Criteria evaluated included egg production, feed consumption, egg weight, egg specific gravity, mortality, and various bone quality parameters. Feeding 0.1% NPP without supplemental phytase decreased egg production (hen-housed) 8.1% over the entire study and 29.6% over the last 4 wk, relative to other diets without supplemental phytase. Similarly, feed consumption of hens fed 0.1% NPP without phytase decreased 5.8% over 17 wk and 13.0% over the last 4 wk. Egg production and feed consumption were maintained at the level of other treatments without phytase when the 0.1% NPP diet was supplemented with phytase (82.1% and 82.4 g per hen per d, respectively). Egg weights and egg specific gravity decreased and mortality increased when hens consumed 0.1% NPP without phytase. Supplementing the 0.1% NPP diet with phytase completely corrected these adverse effects. No deficiency symptoms were observed in hens fed diets containing 0.2 to 0.5% NPP. Phytase supplementation of these diets gave no further improvements in performance.

Response of broilers to graded levels of microbial phytase added to maize-soyabean-meal-based diets containing three levels of non-phytate phosphorus.

Male 1-d-old broilers (n 920) were given 0, 200, 400, 600, 800, 1000 and 1200 U microbial phytase/kg diet in combination with 2.0, 2.7 or 3.4 g non-phytate P (nP)/kg or 4.0, 5.1 or 5.8 g total P (tP)/kg in a 21 d trial to assess the effectiveness of phytase in a maize-soyabean-meal diet. In addition to the above twenty-one diets, a positive control P diet supplied 4.5 g nP/kg, 6.9 g tP/kg and 10 g Ca/kg. The basal diet contained 230 g crude protein/kg, 8.8 g Ca/kg, 4.4 g tP/kg and 2.0 g nP/kg. Defluorinated phosphate and limestone were used to supply P and Ca. A Ca:tP ratio of 2:1 was maintained except in the positive control diet which had a ratio of 1.45:1. Phytase additions linearly increased (P < 0.01) body-weight (BW) gain, feed intake, toe ash percentage, and apparent retention (% of intake) or total amount (g/bird) of retained Ca and P, and linearly decreased (P < 0.01) P excretion (g/kg of DM intake) at each level of nP with the magnitude of the response inversely related to the level of nP. Above-normal mortality was only observed in the group receiving 2.0 g nP/kg diet without phytase. Adding nP linearly increased (P < 0.01) BW gain, feed intake, toe ash percentage, Ca retention, total amount (g/bird) of P retained, and P excretion, and linearly decreased (P < 0.01) apparent retention (%) of P. Derived linear and non-linear equations for BW gain and toe ash percentage at the two lower nP levels, 2.0 and 2.7 g/kg, were used to calculate P equivalency values of microbial phytase. The results show that 939 U microbial phytase is equivalent to 1 g P from defluorinated phosphate in broilers fed on maize-soyabean-meal diets. The amount of P released per 100 U phytase decreased as the total amount of phytase increased.

Response of Turkey Poults to Tiered Levels of Natuphos® Phytase Added to Soybean Meal-Based Semi-Purified Diets Containing Three Levels of Nonphytate Phosphorus

A 3-wk feeding trial using 920 day-old turkey poults was conducted to evaluate the addition of seven levels of phytase (Natuphos®; 0, 200,400,600,800,1,000, and 1,200 U/kg of diet) to diets containing three levels of nonphytate P (nP) (.27, .36, and .45%). A positive control diet contained .60% nP. Semi-purified basal diets contained soybean meal as the only protein source. The increase in BW gain from added phytase was greatest for the lowest nP diet (nP by phytase interaction, P < .001). At .27% nP, gains improved (P < .001) to 800 U of phytase/kg of diet and then reached a plateau. At .36 and .45 % nP, increases in gains were observed only for 200 U of phytase/kg of diet. The highest phytase addition to .36 and .45% nP diets produced gains equal to those of the positive control diet. Feed intake increases paralleled those of BW gains. Gain:feed was lowest for the .27% nP diets without phytase, but improved (P < .001) to 800 U of phytase/kg of diet and then reached a plateau. The high incidence of leg disorders and high mortality (40%) observed for the poults fed the .27% nP diet without added phytase declined with the addition of 200 to 400 U of phytase/kg of diet. Ash percentage of toes and tibias increased as the levels of nP (P < .001) and phytase (P < .01) increased; the magnitude of the response to phytase decreased as nP in the diet increased, resulting in an nP by phytase interaction (P < .001). Tibial shear force and stress responded in a similar manner to increasing levels of nP and added phytase. Results show that 652 U of microbial phytase is equivalent to 1 g of P from defluorinated phosphate in turkey starter diets using soybean meal as the only source of phytate P. The response per 100 U of phytase decreased as the total amount of phytase added was increased.

Evaluation of the Phosphorus Provided by Animal Proteins in the Diet of Broiler Chickens

This study attempted to determine the biological availability of phosphorus in a chick feeding trial. Researchers compared the phosphorus in six samples of poultry byproduct meal and eleven samples of meat and bone meal to a feed-grade mono-dicalcium phosphate. The samples were analyzed to determine moisture, crude protein, fat, ash, crude fiber, calcium, phosphorus, and amino acid content; metabolizable energy was calculated from proximate composition. Diets had adequate but not excessive amounts of all essential nutrients. “Summit” diets containing 0.447% nonphytate phosphorus (NPP) used each of the animal protein sources or the mono-dicalcium phosphorus as the sole source of supplemental phosphorus; these were then blended with a low-phosphorus (0.12% NPP) basal to provide a range on NPP levels. These data indicate no significant difference in relative biological availability of phosphorus in any of the animal protein sources vs. the feed grade mono-dicalcium phosphorus.

Effects of Calcium and Phosphorus Levels in Starter and Grower Diets on Broilers During the Finisher Period

Studies were conducted to determine if the calcium and phosphorus content of diets fed to broilers during the starter and grower period influenced their response to levels fed during the finisher period. Broiler chickens were grown to 42 days on diets with low, medium, or high levels of Ca and nonphytate phosphorus (NPP). At 42 days they were continued on low, medium, or high levels of Ca and NPP, or they were fed diets with no Ca or NPP supplement (Experiment 1); or they were continued on low, medium or high levels of Ca and NPP, or fed diets with 1) removal of supplemental phosphorus; 2) removal of both Ca and NPP supplements (Experiment 2).Body weight gain and feed utilization by broilers fed diets in which Ca and NPP supplements were removed from 42 to 49 days did not differ significantly from those of broilers fed similar diets in which low, medium, or high levels of Ca and NPP were maintained. However, levels of Ca and NP fed prior to 42 days and the removal of both Ca and NPP supplements from 42 to 49 days significantly influenced tibia strength. When broilers were fed low and medium levels of Ca and NPP prior to 42 days, removal of the NPP supplement alone had no adverse effect on tibia strength at 49 days. When a high level of Ca and NPP was fed to 42 days, tibia strength was significantly reduced when the NPP supplement was removed, in comparison to the control group. Maintaining a 2:1 Ca:NPP ratio during the 42- to 49-day period enabled the removal of supplemental dicalcium phosphate with minimal effect on tibia strength.

Effect of Calcium and Nonphytate Phosphorus Levels Fed During 42 to 56 Days of Age on Performance and Bone Strength of Male Broilers

Two identical trials were conducted to determine the optimum level of calcium in conjunction with reduced levels of nonphytate phosphorus (NPP) in diets for male broilers during 42 to 56 days of age. Diets containing .12% and .24% NPP, and calcium levels ranging from .06 to .60%, were compared to a control diet that contained .80% Ca and .35% NPP.Body weight gain, feed consumption, feed conversion, and mortality of male broilers that were fed the treatment diets did not differ significantly from those of broilers that were fed the control diet. All dietary treatments produced birds with visual leg abnormalities, but there were no significant differences among treatments. Diets with reduced levels of Ca and NPP fed to birds during the 42- to 56-day period did not adversely affect tibia length and width when compared to those fed the control diet. At a Ca level of .48%, tibia strength of broilers fed diets with .12 or .24% NPP did not differ significantly from that of broilers fed the control diet. Raising dietary Ca to .60% did not further increase tibia strength when diets contained .12% NPP, but it did increase tibia strength significantly when diets contained .24% NPP.

Shell Quality: Potential for Improvement by Dietary Means and Relationship with Egg Size

Three experiments were conducted by sampling a total of 15,705 eggs from Leghorn hens fed diets varying in methionine, Na, and Ca content. In Experiment 1, birds of four different ages were housed in a common environment and fed diets containing between .233 and .383% methionine. In Experiment 2, birds of five different ages were housed in a common environment and fed diets containing .15, .30, and .45% Na and .25, .45, and .65% nonphytate phosphorus (NPP). In Experiment 3, eggs were sampled from 42 to 62 wk of age in 4-wk intervals from hens fed diets containing from 3 to 9% Ca in increments of 1.5%.Feeding lower levels of methionine (.233%) produced significantly lower egg weights and greater shell strength but at the expense of a decline in egg production at early ages. Reducing the NPP level from .65 to .25% produced lower egg weights and greater shell strength. A corresponding drop in production was not observed except at the .45%-Na level. No significant effects of Na on shell strength were observed. Higher Ca levels produced greater shell strength and had variable effects on egg weight. Increasing the Ca level beyond 6% resulted in a significant decline in production.Regression analyses indicated that within a population, the relationship between egg weight and shell strength is positive. In some instances, the relationship was curvilinear, where the positive association between egg weight and shell strength decreased with increasing egg weights.

Effect of Calcium and Phosphorus on Energy Utilization by Chicks

The effect of calcium and phosphorus on energy utilization by mixed sex broilers was investigated. The calcium and phosphorus deficient basal diet was composed primarily of corn and soybean meal and contained chromic oxide as an indicating substance. The test diets were fed to three replicates of 10 chicks each. Two groups of chicks were fed diets containing either 0.3 or 0.5% non-phytate phosphorus and 1% calcium during the two-week preliminary period. Each group was then subdivided and each subgroup fed either the low phosphorus or the phosphorus adequate diet during a two-week test period. The level of non-phytate phosphorus fed during the preliminary period had no effect on subsequent energy content of the diet. In the second experiment chicks were reared for 10 days and then fed the test diets, which contained 0.2, 0.3, 0.4 or 0.5% non-phytate phosphorus, for 11 days. Each non-phytate phosphorus level was fed with either 1% calcium or at a 2:1 calcium: non-phytate phosphorus ratio. The energy content was reduced (P <0.05) only in those diets sufficiently deficient in non-phytate phosphorus to cause growth depression. The energy content was not reduced in diets containing adequate or borderline adequate levels of non-phytate phosphorus.