Non-phytate Phosphorus Research Articles

Effects and interaction of dietary calcium and nonphytate phosphorus for slow-growing yellow-feathered broilers between 56 and 84 d of age

This experiment investigated the effect and interaction of dietary calcium (Ca) and nonphytate phosphorus (NPP) on growth performance, tibial characteristics, carcass traits, and meat quality for slow-growing yellow-feathered broilers during 56 to 84 d of age. A 3 × 3 factorial arrangement was used, and 720 56-day-old broilers were randomly divided into 9 groups and fed with diets containing different levels of Ca (0.70, 0.80, 0.90%) and NPP (0.30, 0.35, 0.40%) for 28 d. The dietary Ca level affected the ADFI of yellow-feathered broilers (P < 0.05), and the ADFI of birds fed with 0.90% Ca was increased (P < 0.05) compared with that of birds fed with 0.70% Ca. Birds received 0.35 or 0.40% NPP had higher final BW, ADG, and ADFI than those fed with 0.30% NPP (P < 0.05). The tibial diameter of birds fed with 0.80% Ca was increased compared with that of other groups (P < 0.05). The dietary NPP level did not affect tibial characteristics (P > 0.05). The dietary Ca level did not affect carcass traits (P > 0.05). When broilers were fed with 0.30% P, the semieviscerated percentage was increased compared with birds fed with 0.40% NPP (P < 0.05). The dietary Ca level had significant effects on the L∗ value and shear force of the breast muscle, and the dietary NPP level affected the L∗ value and drip loss of the breast muscle (P < 0.05). Furthermore, the effect of interaction between the level of Ca and NPP was observed on the L∗ and a∗ value (P < 0.05). In conclusion, dietary Ca had influence on performance, tibial characteristics, and meat quality of yellow-feathered broilers, and dietary NPP affected performance, tibial characteristics, and carcass traits. Furthermore, the effect of interaction between the dietary Ca and NPP level was observed on carcass traits and meat quality. Considering all aforementioned indicators, 0.80% Ca and 0.35% NPP were recommended for slow-growing yellow-feathered broilers aged 57 to 84 d of age.

Effects of phytase and multicarbohydrase on growth performance, bone mineralization, and nutrient digestibility in broilers fed a nutritionally reduced diet

An experiment was conducted to evaluate the effects of phytase and multicarbohydrase ( MC ) on growth performance, bone ash, and nutrient digestibility in broilers fed a nutritionally reduced diet. A total of 480 Cobb 500 male broilers were randomly allocated to 8 treatments with 6 replicates of 10 birds each. Experimental diets consisted of a positive control ( PC ); a negative control ( NC ) with the reduction of ME, CP, Ca, and nonphytate phosphorus by 75 kcal/kg, 1.5, 0.15, and 0.15%, respectively; NC plus phytase at 500, 1,000, or 1,500 FTU/kg as T3–T5; and further plus MC at 500 mg/kg as T6–T8. Results showed that during 0–18 d of age, feed conversion ratio ( FCR ) was increased ( P < 0.05) in the NC group compared with the PC group; this was recovered ( P < 0.05) in T5 group; BW gain ( BWG ) was increased ( P < 0.05) in T6–T8, and FCR was decreased ( P < 0.05) in T6 and T8, compared with the NC group. For bone mineralization, fat-free dry weight, weight, percentage, and concentration of tibia ash were decreased ( P < 0.05) in the NC group compared with the PC group; T3–T5 increased ( P < 0.05) tibia ash percentage and concentration, compared with the NC group, but only the tibia ash percentage reached to the level that of the PC group; T6–T8 increased ( P < 0.05) tibia ash weight, percentage, and concentration compared with the NC group. Similarly, nitrogen retention and AMEn were decreased ( P < 0.05) in the NC group and recovered in T3–T8; ileal P digestibility also was increased in T3–T8, to a greater level than that in the PC group. The results from contrasts suggested increasing phytase level with or without carbohydrase linearly increased broiler BWG, FCR, bone mineralization, N retention, and ileal P digestibility. Moreover, when combined with carbohydrase, increased phytase level in the diet linearly increased broiler energy utilization, while phytase alone showed no effect on AMEn. In conclusion, supplementation of a combination of phytase and MC could compensate the decreases in growth performance, bone ash, and nutrient digestibility caused by a nutritionally reduced diet.

Dietary resistant potato starch improves growth performance and feather development in Pekin ducks fed a low phosphorus diet

This study investigated whether dietary resistant potato starch (RPS) inclusion could ameliorate the negative impact of a low nonphytate phosphorus (nPP) diet on growth performance, feather growth, feather follicles (FF) development, and carcass traits by improving nutrient utilization and cecal microbiome fermentation capacity in Pekin ducks. The experiment was performed with a 2 × 2 randomized block design with 2 levels of RPS (0 or 12%) and 2 levels of nPP (low or normal, low: 0.22% at 1–14 d and 0.18% at 15–35 d of age; normal: 0.40% at 1–14 d and 0.35% at 15–35 d of age) for a total of 4 treatments, each with 8 replicate pens per treatment of 12 birds per pen. As regards growth performance and carcass traits, RPS inclusion markedly increased (P < 0.05) BW of 14 and 35 d, BWG and FI of 1–14 d, 15–35 d, and 1–35 d as well as abdominal fat and breast meat percentage of 35 d in ducks fed low nPP diets; moreover, RSP inclusion significantly reduced (P < 0.05) mortality in ducks fed low nPP diets. As regards feather growth and follicles development of 35 d, RPS inclusion significantly increased (P < 0.05) the fourth primary feather length, absolute feather weight, and the density of primary FF in the back skin in ducks fed low nPP diets. In regard to nutrition utilization, RPS supplementation significantly increased (P < 0.05) the availability of DM, CP, and energy, as well as dietary AME at 35 d of age in ducks fed low nPP diets. However, RPS supplementation had no effect (P > 0.05) on the concentration of cecal short-chain fatty acids and the activities of cecal phytase and cellulase in ducks fed low nPP diets. These results indicate that RPS can improve nutrient availability to ameliorate the negative effects on performance and feather development caused by a low nPP diet in Pekin ducks.

Evaluation of a novel corn-expressed phytase on growth performance and bone mineralization in broilers fed different levels of dietary nonphytate phosphorus

Summary An experiment was conducted to evaluate the effects of dietary nonphytate phosphorus level and a novel corn-expressed phytase (GraINzyme, Agrivida Inc., Woburn, MA) supplementation on broiler growth performance and bone mineralization. Broilers were fed graded levels of nonphytate phosphorus from 0.20 to 0.44% increased by 0.06% and 4 levels of corn-expressed phytase (500; 1,500; 3,000; and 4,500 FTU/kg). Dicalcium phosphate was used as the reference for inorganic phosphorous. Increasing dietary nonphytate phosphorus level or supplementation of phytase linearly (P

Response of modern broiler chickens to dietary calcium and phosphorus levels below recommendations

This study was carried out to investigate the effects of reduced dietary calcium (Ca) and non-phytate-phosphorus (NPP) levels on performance, carcase yield and bone mineralisation of modern broilers. 11,200 one-day-old chicks (Ross-308) were divided into 7 treatments and 8 replicates with standard recommended level and six different levels of Ca and NPP reduction with completely randomised block design. Treatments were divided into following diets; T1: ross recommended control, T2: 94%, 95% and 91% as percentage of T1, T3: 94%, 95% and 83% as percentage of T1, T4: 94%, 91% and 83% as percentage of T1, T5: 94%, 91% and 77% as percentage of T1, T6: 94%, 86% and 83% as percentage of T1 and T7: 94%, 86% and 77% as percentage of T1 for starter, grower and finisher periods, respectively. Results showed that, the Ca and NPP reduction (T2–T7) through starter period did not significantly (p>.05) affect performance but when considered whole period, quadratically (p<.05) improved body weight gain (BWG), feed conversion ratio (FCR) and European Production Efficiency (EPEF). In line with, Ca and NPP intakes were decrease linearly and quadratically with Ca and NPP reducing in diet and higher intakes at T1 resulted in impaired BWG and FCR. On the other hand, carcase parameters and tibia mineralisation were not significantly affected by the reductions. In conclusion, Ca and NPP requirements of Ross 308 broilers seem to be lower than the Aviagen 2014 and 2019 recommendations and reducing almost 20% Ca and NPP intake of broilers is possible, especially after starter period, to maintain performance without any negative effect on bone development. Highlights Excessive dietary Ca and P feeding have potential deleterious effects on broilers. Dietary Ca and NPP reduction improved growth performance, without impairment bone characteristics. Especially after starter period, Ca and NPP reduction, by keeping the dietary levels as 0.90:0.45, 0.75;0.38 and 0.60;0.30% for starter, grower and finisher phase respectively, seems enough for Ross-308.

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 citric acid, vitamin D3, and high-dose phytase on performance of broiler chicken fed diet severely limited in non-phytate phosphorus

This study investigated effect of various combinations of phytase, citric acid (CA), and vitamin D3 (D3) on phytate P utilization as evaluated by growth performance, serum minerals, and bone characteristics in broiler chickens fed the diet severely limited in non-phytate P. A total of 585 ten-day-old male broiler chickens were allocated to 9 diets from 11 to 38 d of age. There were a positive control (with adequate non-phytate P concentration and 2,000 IU D3/kg in the diet) and 8 diets (without any inorganic P) consisting of D3 (2,000 and 4,000 IU/kg), CA (0 and 15 g/kg), and phytase (0 and 1,500 FTU/kg) in a 2 × 2 × 2 factorial arrangement of treatments with 5 pens per treatment and 13 broiler chickens per pen. Phytase supplementation increased average daily gain and decreased feed to gain ratio, but the effect of phytase was more apparent in broiler chickens received CA (phytase × CA, P < 0.05 and P < 0.01 for average daily gain and feed to gain ratio, respectively). Serum P was increased by phytase supplementation and decreased by CA supplementation, but the decreasing effect of CA was not observed in broiler chickens received phytase (phytase × CA, P < 0.05). Addition of 4,000 IU D3/kg increased breast muscle yield (P < 0.05) and decreased abdominal fat pad (P < 0.05). Phytase supplementation increased carcass yield (P < 0.05) and breast muscle yield (P < 0.001). The individual use of phytase increased bone ash percentage and the combination of 4,000 IU D3/kg and CA increased it, but the inclusion of phytase, CA, and 4,000 IU D3/kg simultaneously did not increase further bone ash percentage (phytase × CA × D3, P < 0.05). Bone strength was increased by phytase supplementation and not affected by supplementation of CA or 4,000 IU D3/kg, but the effect of phytase was more apparent in broiler chickens received CA or 4,000 IU D3/kg; however, the inclusion of phytase, CA, and 4,000 IU D3/kg simultaneously did not increase further bone strength (phytase × CA × D3, P < 0.01). In conclusion, the combination of phytase and CA was more effective than other possible combinations in improving growth performance of broiler chickens fed a diet severely limited in non-phytate P.

Response of broiler chickens in the starter and finisher phases to 3 sources of microbial phytase

A broiler chicken study was conducted for 42 D to evaluate their responses to 3 commercially available microbial phytases. Growth performance, nutrient digestibility, and bone mineralization at days 21 and 42 posthatching were used as parameters of evaluation. The study was a randomized complete block design with 12 treatments, 8 replicate pens, and 25 birds per pen. Treatments included a positive control (PC), a negative control (NC) with crude protein (CP), nonphytate phosphorus (P), and calcium (Ca) reduced by 18, 1.5, and 1.8 g/kg, respectively; the NC + 4 levels of phytase A (250, 500, 750, 1,000 FTU/kg), 3 levels of phytase B (250, 500, 750 FTU/kg), and 3 levels of phytase C (500, 750, 1,000 FTU/kg). Broilers fed the NC diet had reduced (P < 0.05) performance and digestibility measures at days 21 and 42 relative to the PC. All phytase enzymes improved (P < 0.05) BW, gain, feed efficiency, and tibia ash weight and percent. Inclusion of phytase at the highest levels improved (P < 0.05) tibia ash weight by an average of 18.5 and 22% at days 21 and 42, respectively, over the NC. Phytase A linearly improved (P < 0.05) the apparent ileal digestibility (AID) of DM, Ca, P, copper, and sodium at day 21, and the AID of energy, nitrogen, and all amino acid (AA) digestibility at day 42 posthatching. Phytase B linearly (P < 0.05) improved BW gain and feed efficiency of birds at day 21 and quadratically improved (P < 0.05) the AID of nitrogen and all AA in birds at day 42. Supplementation of birds fed the NC with phytase C linearly improved (P < 0.05) the BW gain, feed intake, feed efficiency, and AID of DM, energy, nitrogen, all AA, and all minerals except manganese at day 42. In conclusion, all 3 phytase products improved the growth performance, nutrient and mineral digestibility, and bone mineralization of birds fed diets deficient in nitrogen, Ca, and P similar to or more than birds fed diet adequate in P and CP.

IMPACT OF PHYTASE SUPPLEMENTATION IN RESTRICTED CALCIUM AND PHOSPHORUS BROILER DIETS ON PERFORMANCE, BLOOD PARAMETERS AND BONE CHARACTERISTICS

Six weeks feeding trial using 210 one-day old unsexed Cobb 500 chicks was carried out to study the effects of addingphytase enzyme on growth performance, blood parametersand bone characteristics in broiler chicks. Three starter diets were used from 1 to 21 days; T100 {100% of Ca & non-phytate phosphorus NPP requirements (1.00% Ca and 0.50% NPP)}; T75{75% of Ca & NPP requirements (0.75% Ca and 0.38% NPP)} and T50 {50% of Ca & NPP requirements (0.51% Ca and 0.25% NPP)}. Three grower diets were used from 22 to 42 days; T100 {100% of Ca & NPP requirements (0.91% Ca and 0.46% NPP)}; T75{75% of Ca & NPP requirements( 0.68% Ca and 0.34% NPP)} and T50{50% of Ca & NPP requirements (0.45% Ca and 0.23% NPP)}. Seven dietary treatments were distributed according to diets fed consecutively during starter and grower phases as; (100/100) fed starter T100 then grower T100; (100/75) fed starter T100 then grower T75; (100/50) fed starter T100 then grower T50; (75/75) fed starter T75 then grower T75; (75/50) fed starter T75 then grower T50 and (50/50) fed starter T50 then grower T50.All diets added phytase enzyme (FTU 10000/Ton). Each treatment comprised of 30 chicks in 3 replicates of 10 chicks each. Results showed that live body weight and weight gain did not significantly affected by restricted Ca and NPP diets at starter period, where weight gain was significantly affected at grower period. Birds group received diet containing 100/75 with phytase (T3) gave the highest significant values for LBW and BWG, then 50/50 with phytase (T7) as compared with the other experimental groups during the grower and overall periods.Feed consumption and conversion ratio values were no significant differences among groups fed different dietary treatments during starter and grower phases. Plasma P concentrations was significantly affected however plasma Ca concentrations, GOT and GPT valueswere not significantly affected by the reduction of dietary Ca and NPPwith adding phytase. Percentages of tibia ash, Ca and P were significantly affected by dietary treatments. Supplementation of phytasehas a significant effect ontibia breaking strength, while supplementation of phytase hasn’t any effect on tibia Seedorindex.It is obvious that, the best performance was seen with (100/75) diet without any adverse effect on productive performance, blood parameters and most of tibia measurements and chemical composition.

Inorganic feed phosphate type determines mineral digestibility, broiler performance, and bone mineralization

Summary An experiment was conducted to evaluate early broiler performance, tibia mineralization, and mineral digestibility of broilers fed with diets that differed in inorganic feed phosphates (IFP) but were formulated to be similar in dietary nonphytate phosphorus (nPP) content and calcium-to-phosphorus ratio (Ca:P), total mineral content, or calculated prececal digestible phosphorus (CPDP). Dicalcium phosphate (DCP), monodicalcium phosphate (MDP), monocalcium phosphate (MCP), and defluorinated phosphate were used in formulations with similar nPP content and Ca:P. In addition to these 4 treatments, a mixture of MCP, monosodium phosphate, and DCP was used to assimilate total mineral content of MDP (DMM). Moreover, a mixture of MCP and silicon dioxide was used to produce a similar CPDP content as the DCP diet (MCP + SiO2). The MCP + SiO2 diet had the lowest IFP inclusion. The study used a randomized complete block design with 10 replications of 10 male broilers fed with each of the 6 dietary treatments for 21 D. Linear contrasts were used to compare treatments of interest. Birds fed with MCP demonstrated increased live weight gain, tibia ash (mg/chick), and mineral digestibility compared with birds fed with DCP when diets were formulated to similar nPP content and Ca:P (P

The adaptability of Hy-Line Brown laying hens to low-phosphorus diets supplemented with phytase

Body phosphorus homeostasis network allows laying hens to adapt to wide range of changes in dietary phosphorus levels. Phytase hydrolyzes phytate rendering phosphorus and reduces the laying hens' requirements for inorganic phosphate rock. Here, we demonstrate that there is no need to keep large safety margins in dietary phosphorus when hens are fed with phytase. Hy-Line Brown laying hens (n = 504) were randomly assigned to 7 treatments (6 replicates of 12 birds). A corn-soybean meal–based diet, with no inorganic phosphate rock, was formulated to contain 0.12% nonphytate phosphorus (nPP), 3.8% calcium, and 2,000 FTU/kg phytase. Inorganic phosphate rock (di-calcium phosphate) was supplemented into the basal diet to create 6 other diets containing 0.17, 0.22, 0.27, 0.32, 0.37, and 0.42% nPP. Levels of calcium carbonate and zeolite powder were adjusted to make sure all the 7 experimental diets contained the same nutrition levels (including calcium and phytase) except nPP. The diets were subjected to laying hens from 29 to 40 wk of age. As a result, when supplemented with 2,000 FTU/kg phytase, extra supplementation of inorganic phosphate rock had no effects (P > 0.05) on serum phosphorus levels, serum calcium levels, laying performance (laying rate, egg weight, feed intake, feed-to-egg ratio, and unqualified egg rate), egg quality (shell thickness, shell strength, albumen height, yolk color, and Haugh unit), and tibia quality parameters (breaking strength and ash, calcium, and phosphorus contents). Extra supplementation of inorganic phosphate rock linearly increased (P < 0.01) fecal phosphorus excretion and linearly decreased (P = 0.032) the apparent metabolizability of dietary phosphorus. While serum hormones and intestine gene expressions were varied within treatments, no consistent changes were found. In conclusion, the supplementation of inorganic phosphate rock (provided 0.05–0.30% extra nPP) to phytase-containing basal diets (2,000 FTU/kg; nPP = 0.12%) provided limited benefits to egg production performance in laying hens from 29 to 40 wk of age. Further investigating the body phosphorus homeostasis would help to understand the nutritional and physiological reasonability of formulating low-phosphorus diets in the laying hen industry.

In vitro phytase activity after steam conditioning and pelleting may not consistently correlate with in vivo measurements among commercial phytases

Summary An experiment was conducted to evaluate correlations between in vitro phytase activity after pelleting and broiler performance, tibia mineralization, and plasma myo-inositol of broilers fed diets containing different phytase enzymes conditioned at 3 different temperatures (70°C, 80°C, and 90°C). Dietary treatments included a positive control (0.9% calcium [Ca] and 0.4% nonphytate phosphorus [nPP]) and negative control (NC; 0.7% Ca and 0.2% nPP) and 4 additional diets containing commercially available phytase products (A, B, C, and D) added to the NC based on analyzed activity and manufacturer's recommendations. Treatments were arranged in a 6 (diet formulation) × 3 (conditioning temperature) factorial in a randomized complete block design, with 10 replications of 10 male broilers fed each of 18 dietary treatments for 21 D. Correlations were determined with categorical and replicated data. A conditioning temperature × diet formulation interaction occurred for day 14 and 21 feed conversion ratio (FCR) and day 21 tibia ash (P 0.05), phytase C correlated with tibia ash mg/chick (P = 0.01, r = 0.46), and phytase D showed a moderate correlation with tibia ash mg/chick (P = 0.16, r = 0.26) and plasma myo-inositol concentration (P = 0.15, r = 0.27). This study did not demonstrate a common in vivo performance metric that was correlated with in vitro phytase activity after manufacture among commercial phytase products that decreased in activity because of increased conditioning temperature. Both in vivo and in vitro measurements should be assessed to properly evaluate the efficacy of an enzyme.

Effect of constant 2:1 calcium to non-phytate phosphorus ratio over a range of concentrations during starter-grower and finisher phases on performance of broiler chicken

This experiment investigated the effect of 2:1 ratio of calcium (Ca) to non-phytate phosphorus (NPP) over a range of their concentrations on performance of broilers in phase 1 (1–24 days), phase 2 (25–38 days) and the whole period. A total of 900 male broilers were allocated into 60 pens. In phase 1, dietary treatments were high (H, 9.6 g/kg Ca and 4.8 g/kg NPP), moderate (M, 7.6 g/kg Ca and 3.8 g/kg NPP), low (L, 5.6 g/kg Ca and 2.8 g/kg NPP) and very low (VL, 3.6 g/kg Ca and 1.8 g/kg) level of Ca and NPP. H and M diets showed higher average daily feed intake (ADFI) and serum Ca than those of L and VL diets. There was a linear decrease in tibia Ca and serum P and a linear increase in relative expression of SLC20A1 and CALB1 and retention of Ca and P when concentration of Ca and NPP was reduced. H diet resulted in the highest tarsometatarsus strength and feed conversion ratio (FCR). M and L diets showed higher average daily gain (ADG) than those of H and VL diets. VL diet demonstrated the lowest tibia ash. On day 25, treatments H, M, L and VL received, respectively, 4, 3, 2 and 1 types of finisher diets (H, M, L and VL) during phase 2, resulting in a total of 10 treatments; HH, HM, HL, HVL, MM, ML, MVL, LL, LVL and VLVL. HH vs. HM vs. HL vs. HVL showed a linear decrease of ADFI, ADG, serum P, tibia ash, tarsometatarsus strength and a linear increase of FCR. HH vs. MM vs. LL vs. VLVL demonstrated a linear increase of relative expression of CALB1 and SLC20A1 and a linear decrease of serum P, and in terms of growth performance, MM showed the best results generally. MM vs. ML vs. MVL showed a linear decrease of ADFI and ADG and a linear increase of FCR. HM vs. ML vs. LVL demonstrated a linear decrease of ADG, serum Ca and P and relative expression of CALB1 and a linear increase of FCR (during phase 2). In conclusion, reducing Ca and NPP level over finisher phase, similarly for all combinations of treatments, resulted in poorer performance either in finisher phase or the whole period. Generally, 7.6 g/kg Ca and 3.8 g/kg NPP over the whole period maximized broiler’s performance without negative effects on bone ash and strength.

Phosphorus Restriction Changes the Expression of Fibroblast Growth Factor 23 and Its Receptors in Laying Hens

Dietary phosphorus oversupply wastes non-renewable natural resources and raises environmental concerns in animal agriculture. We hypothesized that laying hens do not need large safety margins for dietary phosphorus because of the existence of fibroblast growth factor 23 (FGF23). In experiment 1, a total of 504 Hy-Line Brown laying hens (40-week-old) were randomly assigned to seven diets (for each diet, six replicates of 12 hens), containing 0.12, 0.17, 0.22, 0.27, 0.32, 0.37, and 0.42% non-phytate phosphorus, respectively, for 15 weeks. In experiment 2, a total of 14 Hy-Line Brown laying hens (40-week-old) were randomly assigned to two diets: (1) phosphorus restricted (n = 7) diet containing 0.14% non-phytate phosphorus, and (2) regular phosphorus (n = 7) diet containing 0.32% non-phytate phosphorus, for 21 days. Laying performance and egg quality were investigated in experiments 1 and 2. Phosphorus excretion and physiological changes were determined in experiment 2. It was found that dietary non-phytate phosphorus levels had no effects (P > 0.05) on laying performance and egg quality in either experiment. In experiment 2, laying hens fed 0.14% non-phytate phosphorus had decreased phosphorus excretion (by 52.6%, P < 0.001) when compared to those fed 0.32% non-phytate phosphorus. In response to the 0.14% non-phytate phosphorus diet, laying hens in experiment 2 exhibited: (1) suppressed calvaria mRNA expressions of FGF23 (by 57.8%, P < 0.001) and fibroblast growth factor receptor 1 (FGFR1, by 52.8%, P = 0.012), (2) decreased serum levels of FGF23 (by 41.7%, P = 0.011) and phosphorus (by 40.3%, P < 0.001), (3) decreased kidney mRNA expressions of FGFR1 (by 66.0%, P = 0.040) and FGFR4 (by 63.3%, P = 0.012) and decreased kidney protein expression of type 2a sodium-phosphorus co-transporter (NPt2a, by 51%, P = 0.025), (4) increased duodenum protein expression of NPt2b (by 45%, P = 0.032), and (5) increased excretion of calcium (by 22.9%, P ≤ 0.024). Collectively, decreasing dietary non-phytate phosphorus by up to 0.12% had no negative effects on egg-production performance but significantly decreased phosphorus excretion in laying hens. The laying hens adjusted to low-phosphorus diets by increasing intestinal NPt2b protein production, which was associated with decreased serum FGF23 concentration. Decreasing dietary non-phytate phosphorus is suggested to laying-hen nutritionists.

Organic trace minerals and calcium levels in broilers' diets to 21 days old

This study was undertaken to evaluate the effects of dietary calcium levels and supplementation with organic trace minerals selenium, copper, iron, zinc and manganese on performance, tissue deposition and litter mineral concentration. A total of 2,496 one-day-old male Cobb 500 broilers were randomly assigned to a 3 × 4 factorial experimental design with three levels of dietary Ca [8, 10 and 12 g kg–1, while maintaining the same Ca:nPP (non-phytate phosphorus) ratio (2:1)] and four levels of micromineral supplementation (0.62, 0.72, 0.82 and 0.92 g kg–1). There was a total of 12 treatments, with eight replicates of 26 birds per pen. Micromineral supplementation (MS) was achieved by adding different levels of the product Bioplex TR Se® and Ca supplementation was achieved by adding increasing levels of limestone and dicalcium phosphate. An interaction between Ca and MS levels was observed (p 0.05) for Ca, P or ash concentrations in the tibia, which were influenced only by dietary Ca levels (p < 0.05). The Ca level of 10 g kg–1 promoted higher Ca and P concentration in the tibia and lower micromineral excretion in the litter. The combination of MS level of 0.82 g kg–1 with Ca level of 10 g kg–1 led to the best BWG response. The supplementation conditions that led to higher micromineral levels in the liver and breast varied for each mineral.

Effect of inorganic phosphate supplementation on egg production in Hy-Line Brown layers fed 2000 FTU/kg phytase

Phytase has long been used to decrease the inorganic phosphorus (Pi) input in poultry diet. The current study was conducted to investigate the effects of Pi supplementation on laying performance, egg quality and phosphate–calcium metabolism in Hy-Line Brown laying hens fed phytase. Layers (n = 504, 29 weeks old) were randomly assigned to seven treatments with six replicates of 12 birds. The corn–soybean meal-based diet contained 0.12% non-phytate phosphorus (nPP), 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase. Inorganic phosphorus (in the form of mono-dicalcium phosphate) was added into the basal diet to construct seven experimental diets; the final dietary nPP levels were 0.12%, 0.17%, 0.22%, 0.27%, 0.32%, 0.37% and 0.42%. The feeding trial lasted 12 weeks (hens from 29 to 40 weeks of age). Laying performance (housed laying rate, egg weight, egg mass, daily feed intake and feed conversion ratio) was weekly calculated. Egg quality (egg shape index, shell strength, shell thickness, albumen height, yolk colour and Haugh units), serum parameters (calcium, phosphorus, parathyroid hormone, calcitonin and 1,25-dihydroxyvitamin D), tibia quality (breaking strength, and calcium, phosphorus and ash contents), intestinal gene expression (type IIb sodium-dependent phosphate cotransporter, NaPi-IIb) and phosphorus excretion were determined at the end of the trial. No differences were observed on laying performance, egg quality, serum parameters and tibia quality. Hens fed 0.17% nPP had increased (P < 0.01) duodenum NaPi-IIb expression compared to all other treatments. Phosphorus excretion linearly increased with an increase in dietary nPP (phosphorus excretion = 1.7916 × nPP + 0.2157; R2 = 0.9609, P = 0.001). In conclusion, corn–soybean meal-based diets containing 0.12% nPP, 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase would meet the requirements for egg production in Hy-Line Brown laying hens (29 to 40 weeks of age).

Modelling and optimizing of calcium and non-phytate phosphorus requirements of male broiler chickens from 1 to 21 days of age using response surface methodology

The skeleton is the main site of P and Ca deposition; therefore, accurate estimation of Ca and P requirements is necessary to maintaining health and optimum performance of broiler chickens. A response surface methodology (RSM) using a central composite design (CCD) was used for evaluating and optimizing of Ca and non-phytate P (NPP) requirements of broiler chickens for optimal performance, ileal nutrient digestibility and bone mineralization from 1 to 21 days of age. A total of 750 one-day-old male broiler chickens (Ross 308) were randomly distributed into 50 cages including 9 treatments, each replicated 5 times (except central treatment with 10 replicates) and 15 birds in each cage by CCD. The dietary Ca levels of 4.3, 5.6, 8.6, 11.7 and 13.0 g/kg and NPP of 2.5, 2.9, 4.0, 5.0 and 5.4 g/kg were used for nine treatments of CCD. The results indicated that the linear and quadratic effects of NPP, quadratic effects of Ca and Ca × NPP were significant for average weight gain (AWG, P < 0.05), average feed intake (AFI, P < 0.05), feed conversion ratio (FCR, P < 0.05) and Ca and P apparent ileal digestibility (AID, P < 0.05); however, the linear effect of Ca was significant only for FCR (P < 0.05). On the other hand, tibia and toe ash were affected by NPP (linear and quadratic, P < 0.01) and Ca (quadratic, P < 0.01). The second-order polynomial regression model was significant for AWG (R2 = 0.93, P < 0.001), AFI (R2 = 0.88, P < 0.001), FCR (R2 = 0.78, P < 0.001), AID of Ca (R2 = 0.78, P < 0.001) and P (R2 = 0.88, P < 0.001), tibia ash (R2 = 0.86, P < 0.001) and toe ash (R2 = 0.85, P < 0.001). The multi-objective optimization indicated that broiler chickens from 1 to 21 days of age need 7.03 and 4.47 g/kg of Ca and NPP, respectively, to achieve optimal AWG, FCR, tibia and toe ash. However, the dietary Ca and NPP levels can be reduced to 6.57 and 3.95 g/kg with a slight negative impact on performance and bone mineralization, respectively. In conclusion, the findings indicate that using multi-objective optimization model such as RSM provides more information regarding optimum Ca and NPP requirements of broiler chickens, considering the complex interaction between these two minerals. While the NPP levels are in line with current recommended requirements, Ca levels are considerably lower and suggest that current recommended Ca requirements may be in excess of the needs of the broiler.

Growth performance, nutrient digestibility, bone mineralization, and hormone profile in broilers fed with phosphorus-deficient diets supplemented with butyric acid and Saccharomyces boulardii

The present study evaluated the effects of butyric acid supplementation and Saccharomyces boulardii (alone or in combination) on growth performance, nutrient digestibility, bone mineralization, and blood hormones of male broiler chickens fed a diet including reduced levels of nonphytate phosphorus (NPP). The chickens were allocated to 6 dietary treatments: 1) positive control diet with adequate amounts of NPP (PC; 0.48, 0.43, and 0.39% in the starter, grower, and finisher period, respectively); 2) negative control diet with low amounts of NPP (NC; 0.38, 0.33, and 0.29% in the starter, grower, and finisher period, respectively); 3) NC plus 500 FTU/kg microbial phytase (PHY); 4) NC plus 0.2% butyric acid (BA); 5) NC plus 1 × 108 cfu/kg S. boulardii (SB); 6) NC plus butyric acid and S. boulardii (BA+SB). Each treatment had 5 pen replicates of 25 birds. After 6 wk, the body weight and ADG in birds fed with any of the diets were higher (P < 0.001) than those in birds fed with the NC diet, where the birds fed with the PHY and BA+SB diets had the highest values. However, only the PHY diet improved (P = 0.041) overall F:G. All diets, except the SB diet, resulted in the increased apparent ileal digestibility coefficient (AIDC) of CP, AMEn, and tibia ash content and decreased serum alkaline phosphatase level compared with the NC diet (P < 0.05). Broiler chickens fed with the PHY, SB, and BA+SB diets also had increased AIDC of phosphorus (P = 0.017) than those fed with the NC and PC diets. Feeding PC, PHY, and BA+SB diets increased (P = 0.007) the tibia phosphorus content but decreased (P = 0.033) serum parathyroid hormone concentration. Overall, the present data indicate that the simultaneous inclusion of butyric acid plus S. boulardii in the low-NPP diets was beneficial for improving growth rate and bone mineralization, but not for feed efficiency.

Effects of Increasing Phytase Inclusion Levels on Broiler Performance, Nutrient Digestibility, and Bone Mineralization in Low-Phosphorus Diets

SUMMARY The objective of the current study was to evaluate the impact of increasing levels of phytase in corn-soy diets fed to male broilers. Experimental treatments included a positive control (PC) with a calculated non-phytate phosphorus (nPP) level of 0.43 and 0.39% for the starter and grower, respectively. The negative control (NC) diet included a reduction in nPP to 0.25 and 0.23% in the starter and grower, respectively, and phytase added to NC diet with increasing levels of 250, 500, 750, 1,000, 2,000, and 3,000/1,000 FTU/kg. All phytase treatments were fed throughout the study with the exception of the 3,000 FTU/kg treatment, which utilized a “step-down” program consisting of 3,000 FTU/kg in the starter being reduced to 1,000 FTU/kg in the grower. Treatment effects on performance, apparent metabolizable energy, apparent ileal digestibility of amino acids, phosphorus, and calcium, and bone mineralization were evaluated on days 14 and 28. The NC diet decreased feed consumption (FC) (P

Effect of anti-fibroblast growth factor receptor 1 antibodies on phosphorus metabolism in laying hens and their progeny chicks

Targeting fibroblast growth factor 23 (FGF-23) signaling pathway is of interest in controlling body phosphate metabolism. This study investigated the effect of anti-fibroblast growth factor receptor 1 (FGFR1, major FGF-23 receptor in the kidney) antibodies on phosphate metabolism. White Leghorn laying hens (65-wk-old) were vaccinated with either a FGFR1 peptide vaccine (five 8-amino-acid peptides were selected, CrZ-1:LPEDPRWE, CrZ-2:LDKDKPNR, CrZ-3:RRPPGMEY, CrZ-4:GSPYPGVP, and CrZ-5:RMDKPSNC) or adjuvant control. At peak antibody titer, hens were artificially inseminated. Chicks from control-vaccinated hens were fed either a non-phytate phosphorus (nPP) sufficient (nPP = 0.45%, positive control) or deficient (nPP = 0.20%, negative control) diet, while chicks from each of the FGFR1 peptide vaccinated hens were fed with the above nPP-deficient diet, for 14 D. When compared to control hens, plasma phosphate in CrZ-1, CrZ-2, CrZ-3, CrZ-4, and CrZ-5 vaccinated hens were decreased by 33, 30, 24, 20, and 26%, respectively (P < 0.05); egg weight in CrZ-2 and CrZ-5 vaccinated hens were increased by 6 and 7%, respectively (P < 0.05); egg production in CrZ-3, CrZ-4, and CrZ-5 vaccinated hens tended to decrease (P= 0.085; decreased by 14, 15, and 13%, respectively). When compared to positive control, chicks from all other groups had decreased body weight gain (BWG) and feed intake (FI) during 1 to 14 D, and had decreased plasma phosphate, tibiotarsus ash, and 24-h phosphorus excretion on day 14. When compared to negative control, BWG of CrZ-1, CrZ-2, CrZ-3, and CrZ-4 antibody chicks were decreased by 23, 28, 26, and 20%, respectively (P < 0.05); FI of CrZ-1, CrZ-2, and CrZ-3 antibody chicks were decreased by 15, 15, and 18%, respectively (P < 0.05); plasma phosphate of CrZ-5 antibody chicks were decreased by 26% (P < 0.05); plasma FGF-23 levels of CrZ-4 antibody chicks were increased by 18% (P < 0.05); tibiotarsus ash content of CrZ-2, CrZ-3, and CrZ-4 antibody chicks were decreased by 20, 20, and 21%, respectively (P < 0.05). In conclusion, anti-FGFR1 peptide antibodies decreased egg production of hens and growth performance of their progeny chicks probably by activating FGF-23 signaling and stimulating FGF-23 production.