Activity of various hydroxylated vitamin D3 analogs for improving phosphorus utilisation in chicks receiving diets adequate in vitamin D3

Effects of calcium, phosphorus, and vitamin D on growing mink (Mustela vison)

The present study investigated the effects of dietary calcium (Ca), phosphorus (P), and vitamin D (VD) supplements on growth performance, Ca:P digestion and metabolism, and serum biochemical indexes of growing male mink (Mustela vison) under conditions of a fixed 2:1 ratio of Ca to P. About 135 dark male mink were randomly assigned to nine groups. The experiment was conducted with a 3 × 3 (Ca:P × VD) factorial design using a corn–fish meal-based diet that contained 2.3% Ca, 1.15% P, and 2100 IU kg−1 VD. The supplementary Ca and P levels were 0%:0%, 0.4%:0.2%, and 0.8%:0.4% of the diets, respectively, whereas supplementary VD levels were 0, 2000, and 4000 IU kg−1. The Ca and P dosage had a significant effect on growth performance of the mink (P < 0.05). The appropriate VD level, which was 4100 IU kg−1, significantly improved protein utilization and Ca and P digestibility of growing mink (P < 0.05). In addition, excreta pollution to the environment was also significantly reduced (P < 0.05). In conclusion, Ca:P (3.1%:1.55%) and VD (4100 IU kg−1) had an important effect on growth performance and protein utilization in growing mink and could reduce environmental pollution by improving protein and P utilization.

Metabolizable energy and standardized ileal digestible amino acid contents of a high-protein sunflower meal fed to broiler chicks

This study was conducted to determine the standardized ileal digestible amino acid (AA) and nitrogen-corrected apparent metabolizable energy (AMEn) contents of a high-protein sunflower meal (HiSFM) fed to broiler chicks. A total of 144 broiler chicks were randomly allotted to one of three dietary treatments with eight replicate cages of six birds. Birds were fed the experimental diets from day 14 to day 21 of age. The results showed that gross energy, crude protein, nonphytate phosphorus, lysine (Lys), methionine (Met), threonine (Thr), and total nonstarch polysaccharide contents of HiSFM were 4178 kcal kg−1, 48.7%, 0.86%, 1.59%, 0.75%, 1.45%, and 14.6%, as-fed basis, respectively. The standardized ileal digestible Lys, Met, and Thr of HiSFM were 12.6, 6.8, and 11.6 g kg−1(dry matter basis), respectively. In addition, the AMEncontent of HiSFM fed to broiler chicks was 1785 kcal kg−1. In conclusion, compared with literature values for sunflower meal, HiSFM had lower standardized ileal digestibility of indispensable AA and higher AMEncontent. The standardized ileal digestible AA and AMEnvalues of HiSFM obtained from the current study could be used when formulating poultry diets and to obtain predictable bird performance.

Suplemento de 1,25 dihidroxicolecalciferol e redução de cálcio e fósforo disponível para frangos de corte

Avaliaram-se o desempenho e o rendimento de carcaça e cortes nobres de frangos de corte machos com suplemento nas rações de 1,25 dihidroxicolecalciferol e redução de cálcio e fósforo disponível. Foi utilizado um delineamento em blocos ao acaso, com seis tratamentos: 0,0; 1,0; 2,0; 3,0; 4,0 e 5,0µg de vitamina D3 ativa/kg de ração, e seis repetições com 17 aves cada. Aos 8 e 42 dias de idade cada unidade experimental foi pesada para avaliação do desempenho. Posteriormente, quatro aves/repetição foram retiradas e abatidas para mensuração do rendimento de carcaça e de cortes nobres. A inclusão da vitamina D3 ativa influenciou positivamente (P<0,05) o ganho de peso e a conversão alimentar com as suplementações de 1,0 e 2,0µg/kg. O consumo de ração não apresentou diferença significativa para os níveis estudados. O rendimento de carcaça e de cortes nobres de frangos de corte machos aos 42 dias não foram influenciados pelo suplemento de 1,25 dihidroxicolecalciferol e redução de cálcio e fósforo disponível nas rações. Recomenda-se o fornecimento suplementar de 1,0 a 2,0µg/kg de vitamina D3 ativa nas rações para frangos de corte machos de 8 a 42 dias de idade.

Effects of phytase and 25-hydroxyvitamin D3 inclusions on the performance, mineral balance and bone parameters of grower-finisher pigs fed low-phosphorus diets

Two experiments, a performance experiment and a mineral balance study, were conducted on grower-finisher pigs (42 to 101 kg live weight) to investigate the effects of Peniophora lycii phytase enzyme and 25-hydroxyvitamin D3 (25-OHD3) on growth performance, carcass characteristics, nutrient retention and excretion, and bone and blood parameters. The two experiments were designed as a 2 × 2 factorial (two levels of phytase and two levels of 25-OHD3). The four diets were T1, low-phosphorous diet; T2, T1 + phytase; T3, T1 + 25-OHD3 and T4, T1 + phytase + 25-OHD3 diet. In all, 25 μg of 25-OHD3 was used to replace 1000 IU of vitamin D3 in diets T3 and T4. Diets were pelleted (70°C) and formulated to contain similar concentrations of energy (13.8 MJ DE/kg), lysine (9.5 g/kg) and digestible phosphorus (P; 1.8 g/kg). Neither the inclusion of phytase nor 25-OHD3 in the diet had any effect on pig performance. There was an interaction between phytase and 25-OHD3 on calcium (Ca) and P retention (P < 0.01) and on the apparent digestibility of ash (P < 0.01), P (P < 0.001) and Ca (P < 0.001). Pigs offered phytase diets only, had a higher retention of Ca and P and digestibility of ash (P < 0.01), P (P < 0.001) and Ca (P < 0.01) compared with pigs offered unsupplemented diets. However, when the combination of phytase and 25-OHD3 were offered, no effects were detected compared with 25-OHD3 diets only. Pigs fed phytase diets had higher bone ash (P < 0.01), bone P (P < 0.01) and bone Ca (P < 0.05) concentrations compared with pigs offered non-phytase diets. In conclusion, pigs offered phytase diets had a significantly increased bone ash, Ca and P than pigs offered unsupplemented phytase diets. However, there was no advantage to offering a combination of phytase and 25-OHD3 on either bone strength or mineral status compared to offering these feed additives separately.

Modifying broiler diets with phytase and vitamin D metabolite (25-OH D(3)): impact on phosphorus in litter, amended soils, and runoff

Adding phytase and 25- hydroxycholecalciferol (25-OH D(3)) to broiler diets has been shown effective at reducing total P concentrations in broiler litter. This study was conducted to determine the impact of field application of broiler litter from modified diets on P solubility in litter-amended soils and P losses in runoff. Five broiler diets and their resulting litters were evaluated: a high P diet, a low P diet, each of those basal diets with phytase added, and a low P diet with phytase and 25-OH D(3) added. A field study was initiated at two sites with each of the five broiler litters and a commercial P fertilizer (triple superphosphate [TSP]) applied at the same total P rate (150 kg P ha(-1)) and a control where no P was applied. Soil P was monitored over time at two depths (0-5 cm and 0-15 cm) soils were collected in the spring and fall to perform rainfall simulation studies. Broiler litter or TSP application increased soil water-soluble P and Mehlich 3-P concentrations relative to the control, however there were no consistent differences detected between litter treatments. Results from the rainfall simulation experiments indicate that diet modification with phytase or 25-OH D(3) does not increase the potential for P losses in runoff from amended soils relative to traditional diets. Moreover, broiler diet modification to reduce excreted P could be a potentially effective method for reducing watershed scale P surpluses in areas of intensive broiler production, without raising concerns over soluble P losses from litter-amended soils.

Corn expressing an Escherichia coli-derived phytase gene: residual phytase activity and microstructure of digesta in broiler chicks

The residual phytase activity, phytic acid P content, and microstructure of the digesta along the gastrointestinal tract (GIT) of broiler chickens fed a corn expressing microbial phytase was studied in a 14-d experiment. The phytase activity of the corn expressing phytase (CBP) was determined to be 660 phytase units/g and was incorporated into broiler diets at varying rates. One hundred forty-four 7-d-old male broiler chickens were grouped by weight into 8 blocks of 3 cages with 6 birds per cage. Three dietary treatments were randomly allotted to the cages within blocks. The corn-soybean meal-based diets consisting of low P and Ca (no added inorganic P) supplemented with 0 (control), 55, or 550 g/kg of CBP (substituting corn) were formulated to contain 0 (control), 36,300, or 363,000 phytase units/kg of phytase activity, respectively. Birds were fed the dietary treatments for 14 d when they were killed and digesta samples from the proventriculus and gizzard, jejunum, and ileum were collected. The residual phytase activity along the GIT increased linearly and quadratically (P < 0.01) with the addition of CBP to the control diets. There was a decrease (P < 0.01) in residual phytase activity as digesta moved distally along the GIT with CBP supplementation. Phytic acid P content significantly decreased (linear, P < 0.01; quadratic, P < 0.05) with CBP supplementation of the control diets. There was substantial degradation (linear and quadratic, P < 0.01) of phytic acid content caudally along the GIT of birds. Extensive cell wall degradation of digesta samples from the proventriculus and gizzard in broilers fed the highest level of CBP compared with birds fed the control diets was observed. The addition of CBP to control diets led to a rapid degradation of the cell walls of digesta and a marked reduction in phytic acid P concentration of digesta in broiler chicks.

Comparative therapeutic effects of orally administered 1,25-dihydroxyvitamin D(3) and 1alpha-hydroxyvitamin D(3) on type-1 diabetes in non-obese diabetic mice fed a normal-calcaemic diet

Frequent injections of the hormonal form of vitamin D(3), 1,25 dihydroxyvitamin D(3) (1,25D3) reportedly inhibits autoimmune type 1 diabetes (T1D) in non-obese diabetic (NOD) mice by correcting some of the abnormalities in antigen-presenting cells which contribute the development of pathogenic T cell responses. This route of administration greatly elevates the levels of these compounds in the bloodstream for hours after treatment, which requires mice to be fed diets formulated to contain much reduced levels of Ca to avoid the toxic effects of hypercalcaemia. In the current work, we demonstrate that feeding 1,25D3 or its synthetic precursor, 1alpha(OH) vitamin D(3) (1alphaD3), as part of a T1D supportive chow diet containing normal levels of Ca, is an effective means of reducing the incidence of disease in NOD mice, but the doses required for protection elicited hypercalcaemia. However, T1D protection elicited by D3 analogue feeding appears, at least partially, to have an immunological basis, as splenic T cells from treated mice had a decreased capacity to adoptively transfer disease. Protection is associated with an increased proportion of T cells with CD4+ forkhead box P3+ regulatory phenotype within the islet infiltrate of treated animals. The 1alphaD3 precursor is converted rapidly to the active 1,25D3 isoform in vivo. However, feeding the 1alphaD3 analogue elicited stronger T1D protection than the 1,25D3 compound, but also induced more severe hypercalcaemia. In future, the dietary supplementation of novel low-calcaemic D3 analogues may enable their continuous delivery at levels that inhibit T1D development in susceptible humans consuming normal levels of Ca.

Phytase and 1alpha-hydroxycholecalciferol supplementation of broiler chickens during the starting and growing/finishing phases

Supplemental 1alpha-hydroxycholecalciferol (1alpha-OHD3) has been shown to have qualitatively similar and quantitatively additive effects to exogenous phytase. Two experiments were conducted from 0 to 35 d in floor pens to determine the additive effect of phytase and 1alpha-OHD3 when supplemented to Ca- and P-deficient diets. In both experiments, at least 4 replicates per treatment (50 chicks per replicate) were used. Corn-soybean-meal-and soybean-oil-based diets were fed and birds were raised in a house impervious to ultraviolet light. During the starter phase (ST), from 0 to 18 d, chicks were fed a 23% CP diet containing 0.60% Ca and 0.47% total P (tP). During the grower/finisher phase (GF), from 19 to 35 d, birds were fed a 19% CP diet containing 0.30% Ca and 0.37% tP. A combination of 1,000 phytase units/kg of Natuphos phytase and 5 microg/kg of 1alpha-OHD3 (P+1A) was supplemented to some of the feed during the ST and GF. Diets containing adequate Ca and P were also fed during the ST (0.90% Ca, 0.68% tP) and GF (0.80% Ca, 0.67% tP). Performance characteristics and the incidence of rickets and tibial dyschondroplasia were measured at 18 and 35 d. In experiment 1, unsupplemented chicks performed well but had considerable leg problems. Chicks fed P+1A during the ST or GF did not perform as well as birds fed P+1A throughout. Birds fed P+1A throughout performed as well birds fed the adequate diets without any indication of leg problems. In experiment 2, unsupplemented birds performed similarly to unsupplemented birds in experiment 1. However, chicks fed the supplements or the control diets did not perform as well or accumulate as much bone ash as birds in experiment 1, although the diets were formulated identically in both experiments. Diets with as little as 0.30% Ca and 0.37% tP appear to be adequate for broilers older than 18 d if supplemented with the correct amounts of phytase and 1alpha-OHD3. However, there are unknown variables that may limit the potential of broilers in terms of bone mineralization and bone pathology, even when adequate diets are fed.

Effects of dietary phosphorus, phytase, and 25-hydroxycholecalciferol on performance of broiler chickens grown in floor pens

Three 49-d experiments (Exp 1, 2, and 3) with broilers in floor pens were conducted to test the applicability of nonphytin phosphorus (NPP) requirements and the NPP-sparing effect of phytase (PHY) and 25-hydroxycholecalciferol (25D) determined previously in battery Exp. Six dietary NPP treatments were tested using a 4-phase feeding program. Treatments 1 to 6 were NRC (1994) NPP (C); University of Maryland (UMD) NPP; UMD NPP - 0.064% (UMD+PHY); UMD NPP - 0.09% (UMD+PHY+25D); NRC - 0.10% (C+PHY), and 90% UMD NPP (NC), respectively. Treatments 3, 4, and 5 had 600 U of PHY/kg of diet. Treatment 4 also had 70 microg of 25D/kg of diet; NPP concentrations were reduced to account for the sparing effect of these additives. No differences in hatch to 49 d BW were observed between treatments in Exp 1 and 2, and only in Exp 3 were the BW of the NC broilers (2.86 kg) different (P < 0.05) from those fed the C, UMD, and UMD+PHY treatments (2.96, 2.94, and 2.98 kg, respectively). Cumulative NPP consumption per bird was lowest (P < 0.05) for broilers fed the UMD+PHY+25D treatment (8.65 g in Exp 3) compared with those fed the C, NC, UMD, and UMD+PHY treatments (18.19, 10.60, 13.63, and 11.01 g, respectively for Exp 3). Application of any of these treatments reduced total P and NPP consumption compared with C. The results of this series of floor pen Exp validate the UMD NPP recommendations for a 4-phase feed program and the PHY and 25D NPP-sparing effects observed in battery trials without negatively affecting broiler performance.

Efficacy of an evolved Escherichia coli phytase in diets of broiler chicks

An evolved Escherichia coli-derived phytase was evaluated for its efficacy in improving growth performance and nutrient utilization of broiler chicks. One hundred forty-four 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 4 birds per cage. Six corn-soybean meal-based mash diets were randomly assigned to cages within each block. The 6 diets were adequate P (7.7 g of P/kg of diet), low P (3.9 g of P/kg of diet), low P diet plus 0.75 or 1.5 g of inorganic P from monosodium phosphate, and low P diet plus the evolved Escherichia coli phytase at 500 or 1,000 units/kg of diet. The chicks were fed the experimental diets from 8 to 22 d of age. The evolved Escherichia coli phytase improved weight gain (P < 0.05), feed intake (P < 0.01), percentage tibia ash (P < 0.01), and retention of P (P < 0.001), Ca (P < 0.01), N (P < 0.05), and a number of amino acids (P < 0.05). The evolved Escherichia coli phytase was, therefore, efficacious in improving broiler growth performance, bone characteristics, and retention of P, Ca, N, and a number of amino acids.

Utilizing Solanum glaucophyllum alone or with phytase to improve phosphorus utilization in broilers

Experiments were conducted to determine if Solanum glaucophyllum (SG), a plant containing a glycoside of 1,25-dihydroxyvitamin D, could be used as a feed additive to improve P utilization of broilers. SG leaves (1, 2.5, or 5 g/kg), 1,25-dihydroxyvitamin D (15 microg/kg), or Ca and P (to achieve a 0.92% Ca:0.65% P:0.41% nonphytate P control diet) were added to a 0.56% Ca/0.45% P/0.28% nonphytate P basal diet and fed to broilers from 7 to 28 d of age. Birds fed basal ration alone exhibited reduced weight gain, bone density, and bone mineral content when compared with birds fed the 0.92% Ca:0.65% P diet. Adding 5 g SG leaves or 15 microg of 1,25-dihydroxyvitamin D/kg to the basal diet increased body weight gain, plasma Ca and P, bone ash, and bone density above basal diet levels. Plasma P and weight gain of birds fed 5 g SG or 15 microg of 1,25-dihydroxyvitamin D/kg basal diet were equivalent to those observed in birds fed the 0.92% Ca:0.65% P diet. In experiment 2, the effect of higher doses of SG, as well as the additive effect of SG with 1,200 phytase units/kg diet, were examined in chicks fed a 0.59% Ca and 0.42% P basal diet. Two levels of SG leaves (7.5 g and 10 g), phytase, or both SG (7.5 g) and phytase were added per kilogram of basal diet. Adding SG or phytase to the basal diet increased weight gain, plasma Ca, plasma P, and bone mineral content over that observed in birds fed basal diet alone. Combining SG with phytase provided no significant gains in growth or bone parameters over treatment with phytase alone.

The Yeast Production System in Which Escherichia coli Phytase is Expressed May Affect Growth Performance, Bone Ash, and Nutrient Use in Broiler Chicks

The efficacy of three Escherichia coli-derived phytase preparations on the performance and nutrient utilization of broiler chicks was evaluated. Two hundred sixteen 7-d-old male broiler chicks were grouped by weight into 6 blocks of 6 cages with 6 birds per cage. Six corn-soybean meal-based diets were randomly assigned to cages within each block. The 6 diets were adequate P, very low P, and low P and contained (g of P/kg of diet) 7.7, 4.0, and 5.1, respectively; and low-P diet plus phytase preparation A, B, or C at 1,000 units/kg of feed. All 3 phytase preparations were produced in different yeast production systems with slightly different glycosylation patterns. Preparation A was produced in Pichia pastoris, B in Schizosaccharomyces pombe, and C in Saccharomyces cerevisiae. The chicks were fed the experimental diets from 8 to 22 d of age. Excreta samples were collected between 17 and 21 d of age. At the end of the study, blood was collected, chicks were killed, and tibiae were removed from 3 birds per cage. Weight gain, feed intake, and feed efficiency among the 3 phytase preparations did not differ, although only phytase A diet outperformed (P < 0.05) the low-P diet in terms of weight gain and feed efficiency. All 3 phytase diets outperformed (P < 0.05) the low-P diet in bone mineral content, density, strength, percentage ash, P retention, and serum P levels. Phytase B diet outperformed the adequate-P diet in bone strength. All 3 preparations increased (P < 0.05) Ca retention with phytase B or C showing a better retention of Ca than phytase A. All 3 phytase preparations showed similar P use as indicated by BW gain and tibia bone characteristics.

Studies on the efficacy of cholecalciferol and derivatives for stimulating phytate utilization in broilers

Studies were conducted to determine the effect of dietary supplementation with cholecalciferol (D3), 1,25-dihydroxycholecalciferol [1,25-(OH)2D3], 1alpha-hydroxycholecalciferol (1alpha-OHD3), and 25-hydroxycholecalciferol (25-OHD3) on utilization of phytate P by broiler chickens. Three experiments were conducted with corn-soybean meal type diets with D3 and 1,25-(OH)2D3 being tested in one experiment and 1,25-(OH)2D3, 1alpha-OHD3, and 25-OHD3 being tested in two experiments of exactly the same design. In the first experiment, high levels of D3 (110 microg and 220 microg/kg of diet) increased phytate P utilization, but the increase was not as great as that obtained from 1,25-(OH)2D3 supplementation. In the other two experiments, 1,25-(OH)2D3, D3 and 1alpha-OHD3 were consistently effective in increasing phytate P utilization as measured by plasma Ca and P, incidence of P rickets, bone ash, and retention of Ca, P, and phytate P. Supplementation with 25-OHD3 in general gave smaller and more inconsistent responses to these criteria, indicating some inconsistency in its ability to improve phytate P utilization.