Concentrations Of Non-phytate Phosphorus Research Articles

Minimum phosphorus requirements for laying hen feed formulations

The objective of this contribution was to summarize from scientific literature the optimal concentration of nonphytate phosphorus (NPP) in feed for laying hens. The considered studies were one meta-analysis from 2012 and original studies published since then. Dietary treatments in the studies included variation in supplementation with mineral P sources and phytase. The studies investigated different periods of production and varied in duration but data were insufficient to analyze such factors in a systematic way. No study showed a positive effect on performance and eggshell when the NPP concentration was increased above 2.2 g NPP/kg of feed without the use of phytase. At such level, no consistent impairment of various bone quality traits were found but only few studies on bone quality traits were published. Overall, the data suggested that not more than 2.2 g NPP/kg of feed is needed for laying hens in different stages of production. This value can be reduced when phytase is added to the feed. Such reduction may differ depending on factors such as phytate content of the feed and phytase dosage. However, data are insufficient for calculating precise values of reduction. While phytate degradation in laying hens was markedly increased by phytase supplementation in several studies, effects of phytase supplementation on performance and bone traits in laying hens were less conclusive probably because the hens were supplied more than their NPP requirement. Transition to a system based on digestible P for laying hens similar to broiler chickens may support more precise P nutrition and more sustainable egg production in the future.

Evaluation of different levels of Bacillus sp. (HCYL03) phytase in broiler chickens fed maize-soyabean meal based diets with a low non-phytate phosphorus content

The objective of the present study was to evaluate the impact of various levels of phytase derived from Bacillus sp. (HCYL03) in corn-soy diets fed to broilers. Experimental treatments included a positive control (PC) with a calculated non-phytate phosphorus (nPP) level of 4.0g/kg for the 35 days of trial. The negative control (NC) diet included a reduction in nPP to 3.0g/kg during the experiment, and commercially available phytase (@500FTU/kg), as well as new bacterial phytase added to the NC diet in increasing amounts of 500, 800, and 1100FTU/kg. Treatment effects on growth performance, the apparent digestibility of P, tibia mineralization, and Ca and P status in blood plasma were evaluated on day 35. The NC diet decreased feed intake (P

Dietary calcium requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age

BackgroundThe current calcium (Ca) recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today. And the response indicators in these studies are mainly growth performance and bone ash percentage. Therefore, the present study was carried out to investigate the effect of dietary Ca level on growth performance, serum parameters, bone characteristics and Ca metabolism-related gene expressions, so as to estimate dietary Ca requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.MethodsA total of 420 1-day-old Arbor Acres male broilers were randomly assigned to 1 of 7 treatments with 6 replicates (10 birds per cage) and fed the corn-soybean meal diets containing 0.60%, 0.70%, 0.80%, 0.90%, 1.00%, 1.10% or 1.20% Ca for 21 days. Each diet contained the constant non-phytate phosphorus content of about 0.39%.ResultsThe average daily gain decreased linearly (P < 0.001) as dietary Ca level increased. The serum and tibia alkaline phosphatase (ALP) activities, tibia bone mineral density (BMD), middle toe BMD, tibia ash percentage, tibia breaking strength, and tibia ALP protein expression level were affected (P < 0.05) by dietary Ca level, and showed significant quadratic responses (P < 0.02) to dietary Ca levels. The estimates of dietary Ca requirements were 0.80 to 1.00% based on the best fitted broken-line or quadratic models (P < 0.03) of the above serum and bone parameters, respectively.ConclusionsThe results from the present study indicate that the Ca requirements would be about 0.60% to obtain the best growth rate, and 1.00% to meet all of the Ca metabolisms and bone development of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.

Effect of high-dose phytase and low calcium concentration on performance of broiler chicken given diet severely limited in nonphytate phosphorus

The effect of phytase and calcium ( Ca ) was investigated on performance of broiler chickens given diets severely limited in nonphytate phosphorus ( NPP ). A total of 550 ten-day-old broiler chickens were allocated to 10 diets from 11 to 40 d of age. There were a positive control (with adequate Ca and NPP concentration) and 9 diets (with 1.4 g NPP/kg) consisting of Ca (5.6, 4.2, and 2.8 g/kg) and phytase (0, 1,500, and 3,000 FTU/kg) in a 3 × 3 factorial arrangement of treatments with 5 pens per treatment. Increasing phytase dose linearly increased BW ( P < 0.001) and tibia ash ( P < 0.001) and reduced feed-to-gain ratio ( F:G , P < 0.001) and mortality ( P < 0.05). Increasing phytase dose quadratically affected tarsometatarsus strength ( P < 0.001) and tibia ash percentage ( P < 0.05). Decreasing Ca concentration linearly increased BW ( P < 0.001) and reduced F:G ( P < 0.001), mortality ( P < 0.01), and tibia ash ( P < 0.05). In terms of BW ( P < 0.05), F:G ( P < 0.01), mortality ( P < 0.05), tibia ash ( P < 0.05), and tarsometatarsus strength ( P < 0.01), response to phytase addition was greater for high Ca concentrations, resulting in a Ca × phytase interaction. Generally, increasing phytase dose or decreasing Ca concentration in severely low NPP diet has beneficial effect on BW, F:G, and mortality of broiler chicken. If performed in combination, performance results improve even more. Nonetheless, when phytase is supplemented in the diet, decreasing Ca concentration does not allow maximum bone strength and ash.

Effect of reduced dietary non-phytate phosphorus concentration, with or without calcium reduction, in diets supplemented with phytase for weaned piglets from 28 to 63 days of age

The aim of this study was to investigate the impact of reduced dietary non-phytate phosphorus (nPP) or nPP and calcium (Ca) concentrations in diets supplemented with phytase on performance, bone mineralisation and serum parameters of weaned piglets from 28 to 63 days of age. A total of 168 barrows and gilts, weaned at 28 days of age, with an average initial bodyweight of 8.11 ± 0.61 kg were randomly allocated in a completely randomised block design. Treatments consisted of a positive control and an additional six treatments, in a 3 × 2 factorial arrangement, totalling seven treatments (Trt). The positive control (PC) diet was formulated to meet or exceed the nutrient requirements of pigs weighing 8–30 kg bodyweight, without phytase supplementation, and the six other diets were formulated similar to the PC, except with a reduction in the nPP concentration of 0.065, 0.130 or 0.195% (Phase Feeding 1 (PF1), PF2 or PF3 respectively) or similar to PF1, PF2 and PF3 minus 0.16% Ca, supplemented with 2000 FTU/kg of phytase, with eight replicate pens/Trt of three piglets each, in a three-phase feeding program. From Day 28 to Day 35, the average daily gain was higher (P &amp;lt; 0.05) and the feed conversion rate was lower (P &amp;lt; 0.05) respectively for piglets fed the PC when compared with those fed PF3 and PC treatment minus 0.160% calcium and minus 0.195% nPP (PF6). In contrast, when evaluating the period from Day 28 to 49, piglets fed PC presented the highest average daily gain, but only differed (P &amp;lt; 0.05) to those fed PF3 and PF6. When considering the overall period, at 63 days of age, no significant difference was detected (P &amp;gt; 0.05) between the PF Trts tested and the PC regarding performance. As for bone mineralisation at 63 days, bone P (BP) decreased as nPP in the diet decreased, regardless of the Ca level. However, except for PF3 and PF6, BP and third metacarpal bone ash concentration were respectively higher for pigs fed the PF Trts, when compared with PC. All treatments containing phytase resulted in a lower bone Ca:BP ratio when compared with PC. Serum P concentrations decreased as nPP in the diet decreased, regardless of the level of dietary Ca. However, with the exception of PF3 and PF6, serum P was not significantly different than pigs fed the PC. In conclusion, reducing nPP or nPP and Ca in diets containing 2000 FTU Ronozyme® HiPhos/kg phytase had no adverse effects on growth performance and increased BP and third metacarpal bone ash concentration compared with pigs fed a nutritionally adequate control diet.

Effect of supplementing graded concentrations of non-phytate phosphorus on performance, egg quality and bone mineral variables in White Leghorn layers

ABSTRACT1. An experiment was conducted to determine optimal non-phytate phosphorus (NPP) concentrations for White Leghorn (WL) layers (22–72 weeks) fed diet containing 38 g Ca/kg.2. Eight diets with graded concentrations (1.5–3.25 g/kg in increments of 0.25 g) of NPP were prepared. Each diet was fed to eight pen replicates containing 88 birds in each. Performance data was evaluated in three different phases (phase I-22–37 weeks, phase II-38–53 weeks and phase III-54–72 weeks). Optimum levels of NPP were determined by fitting a quadratic polynomial (QP) regression model.3. Egg production (EP) was not affected (P = 0.059) by the concentration of NPP and interaction between NPP and diet phase was non-significant, indicating that the lowest concentration (1.5 g/kg diet) of NPP used in the study was adequate across the three phases. However, EP was influenced by phase (P < 0.001).4. Optimum concentration of NPP for feed intake (FI) was estimated to be 1.5, 1.71 and 2.40 g/kg diet during phases I, II and III, respectively. FI per egg mass (EM) or feed efficiency (FE) responded quadratically with NPP and also differed significantly between phases. Optimum concentration of NPP for FE during phases I, II and III was 1.5, 2.56 and 2.32 g/kg diet, respectively.5. Egg weight (EW), EM, shell weight and thickness were not affected by NPP concentration although all of these variables (except shell weight) were influenced by phases.6. Breaking strength of tibia and Ca contents in tibia ash were not affected by the concentration of NPP, but bone ash and P contents in tibia ash were influenced (P < 0.001) by NPP. Predicted optimal concentrations of NPP for responses for tibia ash at 44 or 72 weeks, tibia ash P at 44 weeks and tibia ash P at 72 weeks were 1.55, 2.63 and 1.5 g/kg diet, respectively.7. Based on the results, it was concluded that WL layers required 1.5 g, 2.63 g and 2.4 g, respectively/kg diet during phase I, II and III with the calculated daily intake of 137.3, 278.3 and 262 mg NPP/b/d.

High stocking density alters bone-related calcium and phosphorus metabolism by changing intestinal absorption in broiler chickens.

Live performance, bone health and metabolic responses to the interaction among stocking density and dietary concentrations of total calcium (TCa) and non-phytate phosphorus (NPP) were determined on 2,232 Ross 308 female broilers over a 3-wk experimental period. From 22 d of age, birds were randomly divided into 48 groups and provided with different corn-soybean meal-based diets varying in TCa (0.70% or 0.90%) and NPP (0.28% or 0.36%) content at 1 of 2 stocking densities [28.6 (LSD, 13 broilers/m2) and 39.6 (HSD, 18 broilers/m2) kg of predicted final BW/m2 floor space], according to a 2 × 2 × 2 factorial design with 6 replications in each treatment. Regardless of NPP supplementation, a high-TCa (0.90%) diet aggravated the impact of HSD on growth (BW gain and feed efficiency, P <0.001) and motility (gait score, P <0.001). This might be explained by deteriorating tibia quality (relative weight, mineral composition and biomechanical property; P <0.01), due to the involvement of decreasing duodenal absorption (type IIb sodium-phosphate co-transporter mRNA, P <0.001) in reduced phosphorus retention (P <0.001). On the contrary, increasing dietary NPP (0.36%), particularly if high in TCa (0.90%), boosted TCa retention (P <0.05) by improving absorption (calcium-binding protein D28k transcription, P <0.05) for LSD chickens, hence enhancing bone development (relative tibia weight and tibia breaking strength, P <0.05) and leg health (walking ability, P <0.05). Together, HSD and LSD birds show an impaired TCa tolerance and a higher TCa+NPP threshold, respectively, to allow the optimization of bone quality via altered intestinal absorption.

Influence of dietary calcium concentrations and the calcium-to-non-phytate phosphorus ratio on growth performance, bone characteristics, and digestibility in broilers

Two experiments were conducted to determine the influence of dietary Ca concentrations (Experiment 1) and a combination of dietary Ca and non-phytate phosphorus (NPP) to create distinct Ca-to-NPP ratios (Experiment 2) in corn-soybean meal diets fed to broiler chickens from 2 to 23 d of age. In Experiment 1, dietary treatments consisted of 7 concentrations of Ca (0.4, 0.6, 0.8, 1.0, 1.2, 1.4, or 1.6% of the diet; 7 treatments total), and NPP concentrations were maintained at 0.3%. Increasing the dietary Ca concentration while maintaining 0.3% NPP elicited linear reductions (P <0.01) in overall growth performance and tibia ash. Dietary effects also were observed for apparent retention of P and Ca, which decreased (P <0.05) linearly or quadratically for birds receiving dietary treatments with Ca concentrations greater than 0.6%. In Experiment 2, diets were formulated to contain 3 concentrations of Ca (0.4, 1.0, or 1.6% of the diet) with NPP concentrations either constant at 0.45% or adjusted to maintain a dietary Ca-to-NPP ratio of 2:1 (6 treatments total). Growth performance was not influenced by Ca concentration or the Ca-to-NPP ratio. Tibia break force was lower (P <0.01) in birds fed diets containing 0.4% Ca, regardless of the NPP concentration. Tibia ash increased (P < 0.01) as the dietary Ca concentration increased. Neither the dietary Ca nor NPP concentrations affected nitrogen retention (P >0.05). Upon maintaining a constant 2:1 Ca-to-NPP ratio, P and Ca retention decreased (P < 0.01) at the highest Ca concentration. In conclusion, imbalanced Ca and NPP adversely influenced growth performance and nutrient retention of broilers, indicating the concentrations of Ca and NPP required to maximize bone structure and function may be higher than those required for performance.

Effect of dietary calcium concentrations in low non-phytate phosphorus diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis incidence in growing broiler chickens.

ObjectiveAn experiment was conducted to investigate the effect of dietary Ca concentrations in low non-phytate phosphorus (NPP) diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis (FPD) incidence in growing broiler chickens.MethodsA total of 1,800 21-day-old Ross 308 growing broiler chickens were allotted to 1 of 6 dietary treatments with 6 replicated cages. Six diets were formulated to provide increasing Ca concentrations of 4.0, 5.0, 6.0, 7.0, 8.0, or 9.0 g/kg in diets. The concentrations of NPP in all diets were maintained at 3.0 g/kg, and phytase was supplemented to all diets at the level of 1,000 fytase units (FTU)/kg. At the end of the 14-d feeding trial, birds were euthanized for tibia sampling, and litter samples were collected from 3 areas in the cage. The FPD incidence was measured based on a 6-point scoring system.ResultsDietary Ca concentrations had no effect on growth performance of growing broiler chickens. However, a tendency (linear, p = 0.05) for decreased feed efficiency was observed as dietary Ca concentrations were increased. The concentrations of Ca and P in the tibia of broiler chickens increased (linear and quadratic, p<0.01) with increasing Ca concentrations in low NPP diets containing phytase. Litter pH, moisture, and N contents were not affected by increasing Ca concentrations in low NPP diets containing phytase. However, a tendency (quadratic, p = 0.10) for increased FPD incidence with increasing dietary Ca concentrations was observed.ConclusionDietary Ca concentrations from 4.0 to 9.0 g/kg in low NPP diets containing phytase have little effects on growth performance of growing broiler chickens. However, Ca and P concentrations in the tibia are decreased if dietary Ca concentrations are less than 5.0 g/kg. The FPD incidence for growing broiler chickens may be decreased if less than 9.0 g/kg of Ca is included in diets.

Influence of different levels of calcium, non-phytate phosphorus and phytase on apparent metabolizable energy, nutrient utilization, plasma mineral concentration and digestive enzyme activities of broiler chickens

ABSTRACTThe study investigated the effect of different levels of dietary Ca, non-phytate phosphorus (NPP) and phytase on the nutrient utilization of broiler chickens. A total of 576 day-old broiler chicks (Ross 308) were offered diets containing 3 concentrations of Ca (6, 8 or 10 g/kg diet), 2 concentrations of NPP (3 or 4 g/kg) and 2 concentrations of exogenous microbial phytase (0 or 500 FTU/kg). Diets with high Ca (10 g/kg) reduced (p < .001) the ileal digestibilities of P and protein. The digestibility of Ca and P was negatively (p < .001) affected by high Ca and low NPP (3 g/kg) diet supplemented with phytase. Phytase improved (p < .001) the digestibility of protein and P and also the retention of P and Ca. Phytase supplemented to diets containing 8 g Ca/kg improved (p < .030) the tissue protein content of jejunal mucosa, but reduced (p < .009) the Ca-ATPase activity. Supplemental phytase elevated the plasma P level, especially in birds fed diets containing 6 g/kg Ca and 4 g/kg NPP. In conclusion, phytase supplementation of diets reduced the excretion of minerals by improving their digestibilities; however, this response was dependent on the concentration of dietary Ca and NPP.

Response of broiler chickens to different levels of calcium, non-phytate phosphorus and phytase

ABSTRACT1. Five hundred and seventy six-d old Ross 308 broiler chicks (6 cages per diet, 8 birds per cage in 3 × 2 × 2 factorial arrangement) were fed on maize–soybean meal-based diets containing three concentrations of Ca (6, 8 or 10 g/kg), two concentrations of non-phytate phosphorus (NPP) (3 or 4 g/kg) and two levels of exogenous microbial phytase (0 or 500 FTU/kg) from d 0 to 35.2. Body weight (BW), feed intake (FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.3. Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.4. There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.5. Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.6. These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply.

Impacts of dietary calcium, phytate, and nonphytate phosphorus concentrations in the presence or absence of phytase on inositol hexakisphosphate (IP6) degradation in different segments of broilers digestive tract

A total of 1,440 straight-run Heritage 56M × fast-feathering Cobb 500F broiler birds were fed from 11 to 13 d of age to determine the impacts of calcium (Ca), phytate phosphorus (PP), nonphytate P (nPP) and phytase concentrations on the myo-inositol hexakisphosphate (IP6) flow through the different parts of gastrointestinal tract (GIT). The experiment was a 2×2×2×3 randomized block design with 2 Ca (0.7 and 1.0%), 2 PP (0.23 and 0.34%), 2 nPP (0.28 and 0.45%) and 3 phytase (0-, 500-, and 1,000-phytase unit (FTU)/kg) concentrations. The experiment was replicated twice (block) with 3 replicates per treatment (Trt) of 10 birds per block. Concentration of IP6 in crop, proventriculus (Prov) plus (+) gizzard (Giz) and distal ileum digesta as well as the ileal IP6 disappearance was determined at 13 d of age. In crop, higher IP6 concentration was seen with increased Ca (P < 0.05). Despite the interaction between PP and phytase, higher dietary PP led to greater IP6 concentration (P < 0.05). Similar main effects of PP and phytase were also seen in Prov+Giz and ileum (P < 0.05) without interactions. Interaction between Ca and nPP on IP6 concentration was seen in Prov+Giz (P < 0.05). Decreased ileal IP6 disappearance was found at higher Ca (62.3% at 0.7% Ca vs. 57.5% at 1.0% Ca; P < 0.05). In general, adding phytase improved IP6 degradation but the degree of impact was dependent on nPP and PP (P < 0.05). In conclusion, phytase inclusion significantly reduced IP6 concentration and IP6 disappearance in distal ileum regardless of GIT segments or diet composition, but impacts of dietary Ca, nPP, and PP differed depending on GIT segment examined.

Effects of calcium to non-phytate phosphorus ratio and different sources of vitamin D on growth performance and bone mineralization in broiler chickens

ABSTRACT - A 7 × 2 factorial experiment was designed to test the effects of calcium (Ca) to non-phytate phosphorus (NPP) ratio (1.14, 1.43, 1.71, 2.00, 2.29, 2.57, and 2.86) and different sources of vitamin D (1α-hydroxycholecalciferol (1α-OH-D3) and 25-hydroxycholecalciferol (25-OH-D3)) on growth performance and bone mineralization in 1- to 42-d-old broiler chickens. On the day of hatch, 700 female Ross 308 broilers were weighed and randomly assigned to 14 treatments with five stainless steel cages of 10 birds each. Dietary Ca levels were 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0 g kg−1 and the NPP content was 3.5 g kg−1. The dose of 1α-OH-D3 or 25-OH-D3 was 5 µg kg−1. Diets were not supplemented with cholecalciferol (vitamin D3). Results showed that the Ca to NPP ratio, vitamin D source, and their interaction affected body weight gain (BWG), feed intake (FI), feed efficiency (FE), and carcass and breast yields, as well as tibia weight and length and ash weight in broiler chickens from 1 to 42 d of age. Broilers fed 1α-OH-D3 had higher BWG and FI as well as tibia breaking strength, weight, length, diameter, and ash weight than birds fed 25-OH-D3 at 42 d of age. The Ca to NPP ratio had a quadratic effect on BWG, FI, mortality, as well as tibia breaking strength, weight, length, ash weight, and ash and P contents in 42-d-old broilers. Broiler chickens at 42 d of age obtain optimal growth performance and bone mineralization at the Ca to NPP ratio of 2.32 when 1α-OH-D3 or 25-OH-D3 are used as the vitamin D source.

Effect of dietary nonphytate phosphorus content on ileal lymphocyte subpopulations and cytokine expression in the cecal tonsils and spleen of laying hens that were or were not orally inoculated with Salmonella Typhimurium.

To evaluate the effects of dietary nonphytate phosphorus (NPP) content on ileal lymphocyte subpopulations and cytokine expression in the cecal tonsils and spleen of hens that were or were not inoculated with Salmonella Typhimurium. 64 Salmonella-free hens. Hens were fed a diet with 0.22% (control; n = 32) or 0.42% (high-P; 32) NPP for 6 weeks and then orally inoculated with S Typhimurium (5 × 10(7) CFUs) or PBSS. Tissues were obtained from 8 S Typhimurium-inoculated and 8 PBSS-inoculated hens from each group at 2 and 7 days postinoculation (DPI). Percentages of ileal CD4+ and CD8+ lymphocytes were determined by flow cytometry. Cytokine mRNA expression was determined by quantitative real-time PCR assays. For S Typhimurium-inoculated hens, plasma parathyroid hormone concentration was significantly increased and 1,25-dihydroxyvitamin D3 concentration was decreased in hens fed the high-P diet, compared with values in hens fed the control diet. Salmonella Typhimurium inoculation caused an increase in the percentage of ileal CD8+ lymphocytes and the expression of interleukin (IL)-1β, IL-6, IL-8, interferon-γ, IL-12, and IL-18 in the cecal tonsils and spleen and a decrease in the expression of IL-4 and IL-10 in the cecal tonsils. Hens fed the high-P diet had significantly increased splenic expression of interferon-γ at 2 DPI and IL-1β, IL-6, IL-12, and IL-18 at 7 DPI, compared with hens fed the control diet. Results suggested there was a T-helper 1 cytokine reaction in the cecal tonsils and spleen of S Typhimurium-inoculated hens, and dietary NPP content altered calcium regulation hormone concentrations and affected splenic cytokine expression.

Effect of dietary nonphytate phosphorus on laying performance and small intestinal epithelial phosphate transporter expression in Dwarf pink-shell laying hens

This study examined the effects of various levels of dietary nonphytate phosphorus on laying performance and the expression patterns of phosphorus metabolism related genes in Dwarf pink-shell laying hens. A total of 405 28-week-old Dwarf pink-shell laying hens were fed the same corn-soybean basal meals but containing 0.20%, 0.25%, 0.30%, 0.35% or 0.40% nonphytate phosphorus. The results showed that feed intake, egg production, and average egg weights were quadratically correlated with dietary nonphytate phosphorus content (P < 0.05), and the highest egg production, feed intake and average egg weights were achieved when dietary nonphytate phosphorus was at 0.3% (P < 0.05). mRNA expression of intestinal sodium phosphorus co-transporter linearly decreased when dietary nonphytate phosphorus increased. mRNA and protein expression of intestinal calbindin and vitamin D receptor correlated quadratically with dietary nonphytate phosphorus, and the highest expression was found when dietary available phosphorus was at 0.25% to 0.3%. In conclusion, the ideal phosphorus requirement for Dwarf pink-shell layer hens is estimated to be 0.3% in a corn-soybean diet. With this level of phosphorus supplementation, calbindin and vitamin D receptor reached their highest expression.

Effects of high non-phytate phosphorus starter diet on subsequent growth performance and carcass characteristics of broiler chickens

The trial was performed to investigate the effects of different concentrations of non-phytate phosphorus (nPP) in the starter and grower (with phytase inclusion) periods on carcass characteristics, organ weight and weekly variations of growth performance in the grower period. Seven hundred and twenty-day-old male broiler chickens were randomly assigned to 12 treatments in a completely randomized design. Chickens received two dietary treatments (4.5g/kg and 6g/kg nPP) in the starter (0-21days) and six experimental diets (4g/kg, 3.1g/kg, 2.3g/kg and 2.3g/kg+1000 FTU/Kg of feed phytase, 1.5g/kg, 1.5g/kg nPP+1000 FTU/Kg of feed phytase) in the grower period (22-42days). Results showed that phytase inclusion in the second and third weeks of grower period could increase feed intake significantly. Also, decrease in the concentrations of nPP to 1.5g/kg caused to decline body weight gain markedly. Moreover, there is a significant difference between 4.5g/kg and 6+4g/kg nPP (starter+grower) and 1.5g/kg nPP. Phytase inclusion increased carcass yield and declined liver weight significantly. Dietary treatment of 4.5+1.5g/kg nPP enhanced heart and liver weight markedly. It is concluded that starter diets with increased concentration of nPP (6g/kg nPP) had no beneficial effects on growth performance in the starter and grower period in the total (0-42days). Also, it is possible to decrease nPP concentration of grower diets to 1.5 and 2.3g/kg with and without phytase inclusion respectively.

The effect of dietary supplementation with phytase transgenic maize and different concentrations of non-phytate phosphorus on the performance of laying hens

1. The objective of this study was to evaluate the effects of dietary supplementation with phytase transgenic corn (maize) (PTC) which has a phytase activity of 21 000 units (U) phytase per kg of maize on productive performance, egg quality, tibia bone quality and phosphorus (P) excretion in laying hens. 2. In the experiment, 1800 44-week-old Hy-line brown laying hens were divided into 5 groups with 6 replicates per group and 60 hens per replicate. The experiment lasted for 12 weeks. The layers in the control group (control) were given a basal diet with 0.36% non-phytate P (NPP), while the treatment groups received diets containing 360 U of exogenous phytase/kg with 0.26% NPP (EP) or 360 phytase U of PTC/kg diet with 0.26% (PTC1), 0.21% (PTC2) or 0.16% (PTC3) NPP. 3. The results showed that there was no significant difference in egg production, average daily feed intake, feed efficiency, rate of broken or soft-shell egg production or egg mass among the treatments. There was no significant difference in eggshell thickness or eggshell strength. On the other hand, no differences in any of the bone variables were found between treatments. The faecal P percentage content in EP, PTC1, PTC2 and PTC3 groups was significantly lower than the control group. 4. In summary, the PTC could be used in the feed of laying hens instead of EP to reduce P excretion without effecting production and bone mineralisation.

Effect of inositol and phytases on hematological indices and α-1 acid glycoprotein levels in laying hens fed phosphorus-deficient corn-soybean meal-based diets

The effects of feeding low nonphytate phosphorus (NPP) corn-soybean meal-based diets supplemented with myo-inositol at 0.1%, or with phytase B at 1,300 acid phosphatase units/kg, or with phytase B enriched in 6-phytase A at 300 phytase units/kg on the hematological indices and the α-1 acid glycoprotein (AGP) concentrations in the blood of Bovans Brown laying hens were investigated. The experimental design comprised also a negative control diet and an internal control diet that had the NPP content adjusted by the addition of 0.304 g of monocalcium phosphate per kg to reach the NPP level similar to that resulting from the combined action of both phytases. A total of sixty 50-wk-old hens were randomly assigned to the dietary treatments with 12 cage replicates of 1 hen, and fed the experimental diets until wk 62, when the blood samples were taken and analyzed for basic hematological indices and for AGP concentrations in sera. The hematological indices from all the experimental groups remained in a normal range; nevertheless, the statistically significant effects of diet on hemoglobin concentration (P = 0.003), erythrocyte counts (P = 0.035), the percentage of lymphocytes (P = 0.020), heterophils (P = 0.002), eosinophils (P = 0.023), and basophils (P = 0.001) in the leucocyte population, as well as on the heterophil to lymphocyte ratio (P = 0.003), were observed. The highest erythrocyte counts were characteristic for hens fed the diet supplemented with both phytase A and phytase B. The highest heterophil to lymphocyte ratios were found in blood of hens fed the diet supplemented with phytase B, whereas the highest basophil percentages and the highest AGP concentrations occurred in birds fed the negative control diet. A highly significant correlation was observed between AGP concentrations in sera and BW losses determined previously. The results indicate that the low-NPP corn soybean meal-based diets increased acute phase protein level in laying hens. Phytase B alone, and particularly in combination with phytase A, acted as a potent mediator of the response, whereas supplementary myo-inositol did not.

The effects of feeding high concentrations of cholecalciferol, phytase, or their combination on broiler chicks fed various concentrations of nonphytate phosphorus

SUMMARY Two experiments were conducted to investigate the effects of feeding high concentrations of cholecalciferol (D3), phytase, or their combination on BW gain, FE, tibia ash, and total tract P retention in broiler chicks fed various concentrations of nonphytate P (nPP). In the first experiment, we compared dietary nPP concentrations (0.20, 0.26, 0.33, 0.39, and 0.45%) with supplemental D3 (0, 7,500, and 15,000 IU/kg) for 5- to 23-d-old Ross 308 chicks. In experiment 2, we compared dietary nPP concentrations (0.15, 0.25, 0.35, and 0.45%) with concentrations of D3 (0 or 7,500 IU/kg) and phytase (0 or 1,000 phytase units/kg) for 4- to 18-d-old Ross 308 chicks. The supplementation of D3 resulted in improved FE and total tract P retention in experiment 1, but did not have a positive effect on any of the parameters tested in experiment 2. The addition of higher concentrations of D3 to broiler diets resulted in improved P retention in experiment 1, but did not affect the performance of chicks in either experiment.

Efficacy of different levels of &lt;i&gt;Escherichia coli&lt;/i&gt; phytase in hens fed maize-soyabean meal based diets with a decreased non-phytate phosphorus content

Efficacy of different levels of &lt;i&gt;Escherichia coli&lt;/i&gt; phytase in hens fed maize-soyabean meal based diets with a decreased non-phytate phosphorus content