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To reduce P excretion and increase the sustainability of poultry farms, one needs to understand the mechanisms surrounding P metabolism and its close link with Ca metabolism to precisely predict the fate of dietary P and Ca and related requirements for birds. This study describes and evaluates a model developed to estimate the fate of Ca and P consumed by broilers. The Ca and P model relies on three modules: (1) digestion of Ca and P; (2) dynamics of Ca and P in soft tissue and feathers; and (3) dynamics of body ash. Exogenous phytase affects the availability of Ca and P; thus, to predict the absorption of those minerals, the model also accounts for the effect of phytase on Ca and P digestibility. We used a database to estimate the consequences of dietary Ca, P, and phytase over feed intake response. This study followed a four-step process: (1) Ca and P model development and its coupling with a growth broiler model; (2) model behavior assessment; (3) sensitivity analysis to identify the most influential parameters; and (4) external evaluation based on three databases. The proportion of P in body protein and the Ca to P ratio in bone are the most sensitive parameters of P deposition in soft tissue and bone, representing 91 and 99% of the total variation. The external evaluation results indicated that body water and protein had an overall mean square prediction error (rMSPE) of 7.22 and 12.3%, respectively. The prediction of body ash, Ca, and P had an rMSPE of 7.74, 11.0, and 6.56%, respectively, mostly errors of disturbances (72.5, 51.6, and 90.7%, respectively). The rMSPE for P balance was 13.3, 18.4, and 22.8%, respectively, for P retention, excretion, and retention coefficient, with respective errors due to disturbances of 69.1, 99.9, and 51.3%. We demonstrated a mechanistic model approach to predict the dietary effects of Ca and P on broiler chicken responses with low error, including detailed simulations to show the confidence level expected from the model outputs. Overall, this model predicts broilers' response to dietary Ca and P. The model could aid calculations to minimize P excretion and reduce the impact of broiler production on the environment. A model inversion is ongoing that will enable the calculation of Ca and P dietary quantities for a specific objective. This will simplify the use of the model and the feed formulation process.

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Two experiments were carried out with the objective of evaluating the effect of superdosing of two phytases on performance, egg quality, digestive organ biometry and bone quality of light hens in the first (58 weeks) and second (87 weeks) productive cycle. In the first cycle, 270 light hens were used, in which a completely randomized design was adopted in a 2 x 2 + 1 factorial scheme (bacterial phytase or fungal phytase x 450 FTUs or 900 FTUs + control diet). In the second cycle, 270 hens were used, following the same design as the previous experiment. The performance and quality of the eggs were evaluated in both cycles, and the biometry of the digestive organs and bone characteristics were also evaluated in the first experiment. There was no effect in the comparison between the means for the performance and egg quality (in both experiments), or for the biometric variables and bone characteristics (first experiment). There was no significant interaction between the factors for any of the variables in the two experiments. In the first experiment, egg production was higher with bacterial phytase and egg weight with fungal phytase. The mineral matter showed greater value with 450 FTUs. It is recommended to use bacterial phytase produced from Escherichia coli as it improves the performance of light laying hens. The dosage of 450 FTUs improves the mineral content of light laying hens and the use of phytase in the laying hen diet implies a lower feed cost.(AU)

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The aim of this study was to evaluate the effect of two types of phytases (the 1st produced from Escherichia coli and the 2nd from Aspergillus oryzae) with different dosages (300 and 900 Unit Phytase or FTU) on performance, organ biometry and bone quality of replacement pullets in the period of 8 to 17 weeks of age. A total of 288 Hy-Line White laying hens were used at 8 weeks of age. A completely randomized design was adopted in a 2 x 2 factorial scheme, totaling 4 treatments with 8 replicates of 9 birds each. Performance, biometric variables and bone characteristics were evaluated. There was no significant interaction between the factors for any of the evaluated variables. The conversion and the accumulated consumption were influenced (p 0.05) by the phytase dosages, with the highest results being observed for the consumption obtained with 300 FTU, and the best results for the feed conversion obtained with the dosage of 900 FTU. The relative weight of the liver was influenced by the treatments (p 0.05), presenting higher values with bacterial phytase and a dosage of 900 FTU. The sternum length and tibial deformity were influenced by fungal phytase (p 0.05). It is concluded that the use of 900 FTU superdosing and fungal phytase improves the performance and bone characteristics of light replacement pullets.(AU)

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Although phytase has been researched, new enzymes have been produced, leading to different animal responses. In this scenario, the present study proposes to evaluate the inclusion of a bacterial phytase produced by Escherichia coli in broiler diets based on corn and soybean meal, with or without nutrient reductions, on the performance, nutrient digestibility, phosphorus bioavailability, and bone minerals of those animals and on the economic viability of this practice. A total of 896 male broiler chickens were distributed into 32 experimental units, each housing 28 broilers. The experiment was set up as a completely randomized design with four treatments (Positive Control (PC)- diet meeting the nutritional requirements of the broiler chickens; Negative Control (NC) with reductions of 100kcal/kg of ME, 0.14% avP and 0.11% tCa; NC + phytase (500 FTU/kg); PC + phytase (500FTU/kg)) and 8 replicates. Phytase increased (p < 0.05) feed intake and body weight gain and improved feed conversion ratio in starter (1 to 21 days) and total (1 to 42 days) phases, respectively, compared with Negative Control diet without supplementation. The Negative Control + phytase diet also led to a feed intake similar to Positive Control in the starter and total phases. The inclusion of phytase without nutrient reductions improved (p < 0.05) feed conversion ratio in the starter phase, compared to...(AU)

Embora a fitase tenha sido estudada, novas enzimas foram produzidas, levando a respostas animais diferentes. Nesse sentido, o presente estudo teve como objetivo avaliar a inclusão de fitase bacteriana produzida por Escherichia coli em dietas à base de milho e farelo de soja, com ou sem redução de nutrientes sobre o desempenho, digestibilidade dos nutrientes, biodisponibilidade de fósforo, minerais ósseos e viabilidade econômica. Foram distribuídos 896 frangos de corte machos em 32 unidades experimentais, cada unidade constituída por 28 frangos. O delineamento foi inteiramente casualizado com quatro tratamentos (Controle Positivo (CP) - dieta que satisfaz os requisitos nutricionais das aves; Controle Negativo (CN) - reduções de 100 kcal/kg EM; 0,14% avP e 0,11% tCa); CN + fitase (500 FTU/kg); CP + fitase (500 FTU/kg)) e 8 repetições. A fitase aumentou (p < 0,05) o consumo de ração, o ganho de peso médio e melhorou a conversão alimentar nas fases inicial (1 a 21 dias) e total (1 a 42 dias), respectivamente, em comparação com a dieta Controle Negativo, sem suplementação. O Controle Negativo + fitase também apresentou consumo de ração semelhante ao Controle Positivo nas fases inicial e total. A inclusão da fitase sem redução dos requerimentos nutricionais (Controle positivo + fitase) melhorou (p < 0,05) a conversão alimentar na fase inicial, em comparação com a dieta Controle...(AU)

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This study aimed to evaluate the digestibility of plant energetic ingredients, corn, sorghum and wheat bran, with and without phytase supplementation, in silver catfish (Rhamdia voulezi). The experimental design was completely randomized, represented by eight treatments, which consisted of the development of a reference diet and a test diet for each ingredient evaluated (corn, sorghum and wheat bran), with and without supplemental phytase. Diets were formulated so as to contain 70% reference feed and 30% test ingredient. The digestibility coefficients of dry matter and crude protein were significantly influenced only in relation to the evaluated ingredients. Phytase influenced the digestibility coefficients of energy and phosphorus, with interaction between food and the enzyme addition. The interaction between these two factors shows that the phytase efficiency is dependent on the type of vegetable ingredient used in the diet. The results suggest the supplementation of phytase for a higher nutrient digestibility of corn, sorghum and wheat bran by silver catifish (R. voulezi).(AU)

O objetivo do presente estudo foi avaliar a digestibilidade dos ingredientes energéticos vegetais, milho, sorgo e farelo de trigo, com e sem suplementação de fitase pelo jundiá (Rhamdia voulezi). O delineamento experimental foi inteiramente casualizado, representado por oito tratamentos, os quais consistiram na elaboração de uma dieta-referência e uma dieta- teste para cada ingrediente avaliado (milho, sorgo e farelo de trigo), com e sem a suplementação de fitase. As dietas foram fabricadas de modo que continham 70% da ração referência e 30% do ingrediente teste. Os coeficientes de digestibilidade da matéria seca e proteína bruta foram influenciados significativamente somente em relação aos ingredientes avaliados. A fitase influenciou nos coeficientes de digestibilidade da energia e do fósforo, onde também foi observada a interação entre os alimentos e a inclusão da enzima. A interação entre esses dois fatores demonstra que a eficiência da fitase é dependente do tipo de ingrediente vegetal utilizado na dieta. Pelos resultados obtidos sugere-se a suplementação de fitase visando maior digestibilidade dos nutrientes, do milho, sorgo e farelo de trigo pelo jundiá (R. voulezi).(AU)

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The objective of thisstudywas to evaluatethe effect ofreducedcalcium, phosphorus, energy andamino aciddietsupplemented withphytase forbroilersin the growth phase(14 to28 days)on the ofnitrogen, calciumand phosphorus balance. We distributed392male broilersofCobb, in a completely randomizedin a factorial3 x2 + 1Reduced levelofCaandP; Reduced levels ofamino acidsand energylevelsreducedCa, P, andamino acids x with and withoutenzyme+positive control), seven treatmentswitheight replicatesof sevenchicks each. In the diets with phytasewas used 500 FTU of phytase/ kg diet.Data weresubmitted to varianceanalysisandaverages werecomparedby theF test fororthogonal contrasts. Through the results can be seen that the enzyme phytase used thus of 21,34% reduction in calcium excretion end apparent retention ratio of calcium to 20,16%. Similarly, reductions of nitrogen excretion by 7,56% and phosphorus excretion by 21,34%, the environmental impact reducing caused by the excretion of these nutrientes of these nutrientes and increasing the apparent retention ratio of 9,41 and 33,94% in average, respectively.(AU)

Objetivou-se com este estudo avaliar o efeito da redução de nutrientes e energia suplementada ou não com fitase para frango de corte na fase 14 a 24 dias de idade no consumo, excreção e balanço de nitrogênio, de cálcio e de fósforo. Foram distribuídos 392 frangos de corte em delineamento inteiramente casualizado, utilizando-se arranjo fatorial 3 x 2 + 1 que consistiram de nível reduzido de cálcio e fósforo; níveis reduzidos de aminoácidos e energia; níveis reduzidos cálcio, fósforo, aminoácidos e energia x com e sem enzima + controle positivo, totalizando sete tratamentos com oito repetições de sete aves por unidade experimental. Nas dietas com fitase utilizou-se 500 FTU de fitase/kg de ração. Os dados foram submetidos à análise de variância e as médias comparadas por contrastes ortogonais através do teste F. Os resultados demonstram que a enzima fitase utilizada permitiu diminuir a quantidade de nutriente e energia das rações, proporcionando redução de 21,34% na excreção de cálcio e balanço de cálcio de 20,16%. Similarmente, reduções das quantidades de excreção de nitrogênio em 7,56% e fósforo em 21,34%, diminuindo a excreção desses nutrientes e aumentando o balanço de nitrogênio e fósforo em 9,41 e 33,94% em média, respectivamente.(AU)

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Avaliaram-se o desempenho, o coeficiente de digestibilidade da matéria seca (CDMS), da proteína bruta (CDPB), a retenção aparente de cálcio (Ca) e fósforo (P) e a energia metabolizável aparente corrigida para balanço de nitrogênio (EMAn) de dietas suplementadas com altos teores de fitase (FTU) para frangos, até 35 dias de idade. Foram utilizados 1848 pintos, distribuídos em delineamento inteiramente ao acaso, com sete tratamentos e oito repetições de 35 aves. Os tratamentos foram: T1: dieta-controle; T2: dieta com inclusão de 1.500FTU/kg; T3: 3.000FTU/kg; T4: 4.500FTU/kg; T5: 6.000FTU/kg; T6: 8.000FTU/kg e T7: 10.000FTU/kg de ração. No 10º e 28º dias de experimento, quatro e três aves, respectivamente, foram transferidas para gaiolas de metabolismo. A partir da inclusão de 4.500FTU/kg, o desempenho das aves de 1 a 35 dias foi semelhante ao das aves do grupo-controle (P>0,05). Não houve diferença (P>0,05) entre os tratamentos nos CDPB e nos valores de EMAn, porém, na fase inicial, observou-se maior aproveitamento da MS com os altos níveis de fitase (P<0,05). Em relação à retenção de Ca e P, houve efeito positivo da suplementação enzimática, com aumento significativo do uso desses minerais pelas aves. Concluiu-se que é possível suplementar altos teores de fitase valorando adequadamente os nutrientes da dieta.(AU)

The digestibility of dry matter (DMD), and of crude protein (CPD), the apparent retention of calcium (Ca) and phosphorus (P) and apparent metabolizable energy corrected by nitrogen balance (AME) of diets supplemented with high levels of phytase (FTU) for broilers, 35 days old were evaluated. A total of 1848 chicks were distributed in a completely randomized experiment with seven treatments and eight repetitions. The treatments were: T1: control diet, T2: inclusion of 1,500FTU/kg; T3: 3,000FTU/kg; T4: 4,500FTU/kg; T5: 6,000FTU/kg; T6:8,000FTU/kg; and T7: 10,000FTU/kg feed. On the 10th and 28th days of the experiment, four and three birds, respectively, were transferred to metabolism cages. An addition of 4,500FTU/kg from 1 to 35 days resulted in a performance similar to the control group (P>0.05). There was no difference (P>0.05) among treatments for DMD and AME, however, during the initial phase there was a higher use of MS with high levels of phytase (P<0.05). Regarding the retention of Ca and P, a positive effect of enzyme supplementation significantly increased the use of these minerals by birds. It is possible that high levels of supplemental phytase adequate valuing the nutrients.(AU)

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In order to evaluate the variability in concentration of secondary metabolites among grains from different sorghum hybrids (Sorghum bicolor (L) Moench) and provide some information for rational use in animal feeds, grain samples were collected from 12 hybrids (Criollo 1, Criollo 27, Chaguaramas III, Chaguaramas VII, Cristiani Burkard H-8046-2, Guanipa 95, Himeca 101, Himeca 400, Pioneer 81-G67, Pioneer 83-G88, Pioneer 86-P42 y Tecsem 120) sowed on 2008 in the Turén municipality, Portuguesa State-Venezuela. Using standardized analytical methods, hybrids showed polyphenolics compounds contents (0.92 +/- 0.37% TaE), total (0.61 +/- 0.29% TaE) and condensed tannins (0.95 +/- 0.65% LeuE), phytic phosphorus (0.17 +/- 0.03%) and intrinsic phytase activity (12.3 +/- 6.74 U/kg) in the ranges described in the literature, with an important variation among hybrids that must be considered for their inclusion levels in the formulation of balanced feeds, as well as plant breeding programs.

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