Luciana de Paula Naves

Componentes antinutricionais e digestibilidade proteica em sementes de abóbora (Cucurbita maxima) submetidas a diferentes processamentos

Vegetable subproducts have been used in diets with the purpose of improving the nutritional quality of undernourished populations. However, the antinutrients present in those foods can cause adverse health effects. Therefore, the contents of polyphenols, cyanide, saponins, trypsin inhibitor, hemaglutinin activity, and the percentage of the in vitro protein digestibility of raw and thermally treated pumpkin seeds were investigated with the objective of selecting the processing that results in major antinutrient reduction and greater protein digestibility. Pumpkin seeds (Cucurbita maxima) were submitted to the following treatments, which were carried out in quadruplicate: used raw; boiled for 5, 10, and 15 minutes; and steamed for 10 minutes. Next, the seeds were freeze-dried, grinded, and stored at room temperature until the analyses were completed. There was no significant difference among the treatments as for the levels of polyphenols. The raw seeds showed the highest content of cyanide, smallest level of trypsin inhibitor, and smallest protein digestibility. The 10-minute boiling resulted in the lowest content of saponins and greatest protein digestibility. No Hemaglutinin activity was detected in the samples. It can be concluded that the 10-minute boiling was the treatment that produced better results.

Diets with reduced levels of nutrients supplemented with phytase and amino acids for broilers

Um experimento de desempenho e outro de metabolismo foram conduzidos simultaneamente com frangos de corte de 22 a 35 dias de idade, avaliando-se cinco dietas em seis repeticoes. A dieta controle, sem fitase, continha 19% de proteina bruta (PB); 0,412% de fosforo disponivel (Pdisp) e 0,824% de calcio (Ca). As demais dietas foram suplementadas com fitase e formuladas com 0,262% de Pdisp e 0,524% de Ca, tendo o teor de PB variado em 19 ate 16%. No ensaio de desempenho, 750 aves foram utilizadas, avaliando-se o desempenho, o teor de cinzas na tibia e rendimentos de carcaca, cortes e gordura abdominal, aos 35 dias de idade. O ensaio de metabolismo foi realizado com 90 aves, determinando-se a energia metabolizavel aparente, corrigida pelo balanco de nitrogenio e o coeficiente de metabolizabilidade da materia seca (CMMS) das racoes, e tambem o balanco e retencao de nitrogenio (N) e fosforo (P). As dietas nao influenciaram o desempenho, teor de cinzas na tibia e os rendimentos de carcaca, peito e coxa + sobrecoxa. Entretanto, as aves alimentadas com a racao contendo 16% de PB apresentaram maior teor de gordura abdominal. As racoes com 19% de PB apresentaram menor valor energetico e CMMS. A retencao de N e P foi maior nas aves que receberam as racoes com reduzidos teores de PB e fitase. Portanto, quando a racao de frangos de corte e suplementada com fitase e aminoacidos e possivel reduzir a PB, Pdip e Ca em ate 16; 0,262 e 0,524%, respectivamente.

Níveis de cálcio e fósforo disponível em rações com fitase para frangos de corte nas fases pré-inicial e inicial

Two independent experiments, one in pre-starter phase (1 to 7 days) and the other in the starter phase (8 to 21 days of age), were carried out with broilers to evaluate levels of calcium and available phosphorus (aP) in diets supplemented with 500 units of phytase activity/kg of diet. Each experiment consisted of a performance and a metabolic assay, and was conducted in a factorial schedule (3 × 4) + 1, with three aP levels (0.42, 0.37, 0.32% in the pre-starter phase and 0.39, 0.34, 0.29% in the starter phase), four calcium levels (0.94, 0.84, 0.74, 0.64% in the pre-starter phase and 0.88; 0.78, 0.68, 0.58% in the starter phase) plus a control diet. The control corresponded to the only diet without phytase and contained 0.47% of aP and 0.94% of calcium (pre-starter phase) or 0.44% of aP and 0.88% of calcium (starter phase). In the performance assays, at 7 and 21 days of age the feed intake, weight gain, feed conversion and the ash content in the tibia were evaluated. In the metabolic assays the apparent metabolizable energy corrected for nitrogen balance (AMEn) of the feed, and dry matter digestibility coefficients (DMDC) were determined. Calcium levels influenced the feed intake, AMEn and DMDC in the prestarter phase, and in the starter phase they influenced bone ash, AMEn and DMDC. The aP levels influenced the content of tibia ash, AMEn and DMDC in the pre-starter phase, and bone ash and DMDC in the starter phase. By adding 500 units of phytase activity/kg of diet, it is possible to reduce, respectively, the calcium and aP levels to 0.64% and 0.37% in the prestarter phase, and to 0.58% and 0.29% in the starter phase, since this reduction does not cause a negative effect on performance or bone mineralization of broilers in the evaluated periods.Dois experimentos independentes, um na fase pre-inicial (1 a 7 dias) e outro na fase inicial (8 a 21 dias de idade), foram realizados com frangos de corte para avaliar niveis de calcio e fosforo disponivel (Pdisp) em racoes suplementadas com 500 unidades de atividade de fitase/kg de racao. Cada experimento constou de um ensaio de desempenho e outro de metabolismo e foi conduzido em esquema fatorial (3 × 4) + 1, sendo tres niveis de Pdisp (0,42; 0,37; 0,32% na fase pre-inicial e 0,39; 0,34; 0,29% na fase inicial), quatro niveis de calcio (0,94; 0,84; 0,74; 0,64% na fase pre-inicial e 0,88; 0,78; 0,68; 0,58% na fase inicial) mais uma racao controle. O controle correspondeu a unica racao sem fitase e continha 0,47% de Pdisp e 0,94% de calcio (fase pre-inicial) ou 0,44% de Pdisp e 0,88% de calcio (fase inicial). Nos ensaios de desempenho, aos 7 e aos 21 dias de idade, foram avaliados o consumo de racao, o ganho de peso, a conversao alimentar e o teor de cinzas na tibia. Nos ensaios de metabolismo, determinaram-se a energia metabolizavel aparente corrigida pelo balanco de nitrogenio (EMAn) das racoes e os coeficientes de digestibilidade da materia seca (CMMS). Na fase pre-inicial, os niveis de calcio influenciaram o consumo de racao, a EMAn e o CMMS e, na fase inicial, afetaram o conteudo de cinzas osseas, a EMAn e o CMMS. Os niveis de Pdisp influenciaram o teor de cinzas na tibia, a EMAn e o CMMS na fase pre-inicial e as cinzas osseas e o CMMS na fase inicial. Adicionando 500 unidades de atividade de fitase/kg de racao, e possivel reduzir, respectivamente, os niveis de calcio e Pdisp para 0,64% e 0,37% na fase pre-inicial e 0,58% e 0,29% na fase inicial, pois essa reducao nao tem efeito negativo sobre o desempenho e a mineralizacao ossea dos frangos de corte nessas fases.

Nutrientes e propriedades funcionais em sementes de abóbora (Cucurbita maxima) submetidas a diferentes processamentos

O objetivo deste trabalho foi verificar a influencia dos processamentos termicos sobre os nutrientes e propriedades funcionais das sementes da abobora Cucurbita maxima. As sementes foram, em quatro repeticoes, submetidas aos seguintes processamentos: utilizadas na forma crua; cozidas em agua em ebulicao por tres tempos: 5, 10 e 15 minutos; e cozidas no vapor por 10 minutos. Posteriormente foram liofilizadas, trituradas e armazenadas em temperatura ambiente ate a realizacao das analises de composicao centesimal, minerais e propriedades funcionais. Nao houve diferenca significativa entre os processamentos para os niveis de proteina bruta, fibra alimentar, extrato etereo, cinzas, S, P, Mg, Ca, Cu, Zn, solubilidade do nitrogenio (nos pH 4, 5 e 6), absorcao de agua e oleo, volume de espuma e estabilidade de emulsao. O cozimento em agua em ebulicao reduziu o teor de K. Todos os processamentos termicos diminuiram os niveis de Mn e Fe. As sementes cruas apresentaram a maior solubilidade do nitrogenio nos pH 2, 3, 7, 8 e 9. Conclui-se que os processamentos acarretaram diferenca significativa apenas nos teores de K, Mn, Fe e solubilidade do nitrogenio; e que as sementes apresentam potencial para serem incorporadas, provavelmente, em alimentos que requeiram elevada taxa de absorcao de oleo.

Fontes e níveis de glicerina para frangos de corte no período de 8 a 21 dias de idade

umidade da cama de pintos de corte recebendo racoes com diferentes niveis e fontes de glicerina. Foram utilizados 1300 pintos de corte machos Cobb 500, num arranjo fatorial 4x3+1, com delineamento inteiramente casualizados, sendo quatro niveis de inclusao (17,5; 35,0; 52,5 e 70,0g/kg) de tres glicerinas (bruta de soja (GS), bruta mista (GM) e semipurificada (GPUR) nas dietas isonutritivas e um tratamento sem glicerina, sendo que para as fontes e niveis de glicerina foram teste de Student-Newman-Keuls e analise de regressao, respectivamente; e para o tratamento, teste de Dunnett. Utilizou-se quatro repeticoes e 25 aves por parcela. O consumo de racao foi influenciado (P<0,05) pelas fontes de glicerina, sendo a GM a fonte que promoveu menor consumo nas aves, porem, nao houve diferenca dos tratamentos em relacao ao controle. Nao houve diferenca significativa para o ganho de peso. Houve interacao dos niveis e fontes de glicerina para a conversao alimentar. Para a GS, a melhor conversao alimentar com a inclusao de 50,35g; para a GM, houve uma piora linear com o aumento da inclusao de glicerina. Houve interacao para a concentracao de glicerol serico nas aves, obtendo aumento linear nas aves que ingeriram a GS e GPUR, e reducao linear para a GM. O ganho de umidade da cama foi influenciado pelas fontes de glicerina, sendo que a mista apresentou menor umidade. As glicerinas estudadas podem ser incluidas nas racoes para pintos de corte ate 70,0g/kg, sem prejudicar o desempenho dos animais. Palavras-chave: aves, desempenho, glycerol, umidade de cama.

Níveis de fósforo disponível e cálcio em rações suplementadas com fitase para frangos de corte nas fases de crescimento e final

Calcium and available phosphorus (aP) levels in diets with phytase for Cobb broilers in the growing (22 to 35 days) and finishing phases (36 to 42 days of age) were evaluated. A 3 × 4 + 1 factorial scheme, with three aP levels (0.36, 0.31, 0.26% in the growing phase and 0.33, 0.28, 0.23% in the finishing phase), four calcium levels (0.82, 0.72, 0.62, 0.52% in the growing phase and 0.76, 0.66, 0.56, 0.46% in the finishing phase), and one level of supplementation of phytase (500 ftu/kg) was used. Control diets were not supplemented with phytase and they contained, respectively, the following levels of aP and calcium: 0.41 and 0.82% (growing phase) and 0.38 and 0.76 (finishing phase). In the performance assays, at 35 and 42 days of age, feed intake, weight gain, feed conversion and the ash content in the tibia were evaluated. In the metabolic assays, the energy values of diets (AMEn) and dry matter digestibility coefficients (DMDC) were determined. In the growing phase, the reduction of the calcium and aP to 0.52 and 0.26%, respectively, did not compromise performance, bone ash, AMEn or MCDM. In the finishing phase, the reduction of the calcium and aP to 0.56 and 0.28%, respectively, did not compromise performance, AMEn or MCDM; in addition to improving bone ash. The levels of calcium and aP of diet can be reduced to 0.52 and 0.26% in the growing phase, and to 0.56 and 0.28% in the finishing phase, provided that this reduction is combined with supplementation of fitase at 500 ftu/kg of the diet.

Activity of fungal phytases stored in two ways in response to the period of storage at room temperature

Two distinct experiments were conducted simultaneously with phytases of Aspergillus oryzae and A. niger for determining enzyme activity in response to storage period (up to 180 days at room temperature - RT). In the first experiment, enzymes were stored as they were acquired (pure form) and the activity was measured periodically during 180 days of storage at RT. In the second experiment, the phytases were incorporated to a supplement containing vitamins, minerals, and amino acids; and then this supplement was stored at RT up to 180 days, so that every 30 days of storage was collected one aliquot from each replicate for determining enzymatic activity. In conclusion, the phytase activity is affected by storage duration. To ensure 80% of the initial activity, the phytases of A. oryzae and A. niger can be stored in the pure forms for up to 53 and 135 days at RT, respectively. However, if the phytases of A. oryzae and A. niger are incorporated to a supplement containing vitamins, minerals, and amino acids then the storage period at RT should not exceed 67 and 77 days, respectively.

Efficiency of microbial phytases in diets formulated with different calcium:phosphorus ratios supplied to broilers from 35 to 42 days of age

ABSTRACT The aim of this study was to investigate the efficiency of six microbial phytases (named of A to F) supplemented in diets (1500 FTU/kg) formulated with three different calcium:available phosphorus ratios (3.5:1.0, 5.0:1.0 and 6.5:1.0). Moreover, one positive control diet without phytase that was formulated with a calcium:available phosphorus (Ca:AP) ratio of 6.5:3.0 was also considered. The utilization of dietary nutrients, as well as the bone, plasma and performance parameters of broilers from 35 to 42 days of age was evaluated. Phytase D increased the P and magnesium plasma concentrations. Broilers fed diets containing phytase B showed a lower feed intake and weight gain, while the birds fed diets containing phytase E consumed more feed, gained more weight and excreted less total P. The highest Ca retention and also the best nitrogen utilization were determined when the diet contained phytase D or E. For all phytases evaluated, an increased in the dietary Ca:AP ratio increased the tibia ash content and the Ca balance. Phytase utilization reduced the phytate P excretion, improving its utilization by the broilers. For the rearing period evaluated, it is possible to reduce the AP of the diet to 1.0 g/kg when Ca is maintained at 6.5 g/kg, and the diet is supplemented with 1500 FTU of phytase A, B, C, D or E/kg. This diet allows the maintenance of performance, optimizes the bone mineralization, and it improves the Ca, total P, phytate P and nitrogen utilization in addition to reducing the P excretion.

Redução de fósforo em dietas para frangos com base em valores de equivalência da fitase

The objective of this work was to evaluate the use of equivalency values of phytase as a basis for reduction of available phosphorus (aP) in broiler diets. Ten nutritional programs were evaluated with six replicates of 15 birds each. The following were evaluated: performance, tibia ash content, and feed costs. From 1 to 7 and 36 to 42 days of age, the birds received basal diet; from 8 to 21 days, diet without phytase containing 3.9 g kg-1 aP and four diets with phytase containing from 1.1 to 2.5 g kg-1 aP; and from 22 to 35 days, diet without phytase containing 3.4 g kg-1 aP plus diet with phytase containing 1.6 g kg-1 aP. The best nutritional plan was formed by the diets: 4.7 g kg-1 aP without phytase (1 to 7 days); 2.0 g kg-1 aP supplemented with phytase (8 to 21 days); 3.4 g kg-1 aP in feed without phytase (22 to 35 days); and 3.0 g kg-1 aP in feed without phytase (36 to 42 days). The reduction of aP occurs in the period from 8 to 21 days of age and corresponds to 2.0 g kg-1 of feed supplemented with phytase.

Níveis da bacitracina de zinco como melhorador do desempenho de frangos de corte

The use of growth promoters in the broilers production is a common practice in the poultry industry and its use must be made accordance with limits in Brazil set by the Ministry of Agriculture, Livestock and Supply (MAPA).The main objective of this study was to verify the effect of the use of zinc bacitracin, within the levels recommended by the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), in broiler diets for the performance of birds from 1 to 42 days old. We used a randomized design with five treatments in 10 replications of 25 male chicks from Cobb cut 500®, totaling 1250 birds. The treatments consisted of five inclusion levels of zinc bacitracin (0, 10, 25, 40 and 55ppm). The variables studied were feed intake, weight gain, feed conversion and economic evaluation of feed. For the breeding period as a whole, this study also evaluated the viability of broilers. Zinc bacitracin was effective as growth promoter of broilers reared during 1 to 21, 1 to 35 and 1 to 42 days. For the period 1-21 days, using 55 and 29.3ppm of zinc bacitracin resulted in a lower feed intake and increased weight gain, respectively. In general, the best feed conversion was obtained when 55ppm of zinc bacitracin was added to the feed of broilers.