Luziane Moreira dos Santos

Energy values and chemical composition of spirulina (Spirulina platensis) evaluated with broilers

ABSTRACT - The objective of this study was to determine the chemical and energy composition of spirulina ( Spirulinaplatensis ), the nutrient metabolizability coefficients, and the values of apparent metabolizable energy (AME) and the apparentmetabolizable energy corrected for nitrogen balance (AMEn) in broilers. A digestibility trial was carried out by using totalexcreta collection method, with 90 Cobb 500 lineage chicks, with initial weight of 256 ± 5 g at 11 days of age. Birds were allottedin metabolic cages for 10 days, distributed in a completely randomized design, with three treatments and six repetitions withfive birds each. Diets consisted on a reference-ration based on corn and soybean meal and two test diets, one containing spirulina(30%) and the other one with soybean meal (30%). Spiruline was superior to soybean meal for contents of dry matter (DM),gross energy (9.60%), crude protein (26.56%), ether extract (54.45%), mineral matter (42.77%), calcium (100%) and totalphosphorus (130.77%) and also for most amino acids, except lysine, glutamate, histidine and proline. Nevertheless, spirulinepresented lower values of gross fiber (83.95%), acid detergent fiber (85.12%) and neutral detergent fiber (6.15). The AMEand AMEn values (kcal/kg of DM) were, respectively, 2,906 and 2,502 for the spirulina and 2,646 and 2,340 for the soybeanmeal and AMEn of spirulina was 6.92% higher than soybean meal.Key Words: non-conventional food, nutritional value, total collection

Activity of glutamate dehydrogenase and protein content in the breast of broilers fed diets containing different sources and levels of glycerine

According to scientific literature, glycerol in the diet can spare glucogenic amino acids by inhibiting the activity of enzymes, such as glutamate dehydrogenase, thereby promoting protein deposition in muscle tissues. Therefore, the objective of this study was to evaluate the effect of three sources of glycerine (crude glycerine from soybean oil--CGSO, mixed crude glycerine from frying oil and lard--MCG and a semipurified glycerine from soybean oil--SPGSO) in four concentrations in the diet (17.5, 35.0, 52.5 and 70.0 g of each type of glycerine/kg of feed) on the activity of hepatic glutamate dehydrogenase, performance and protein content in the breast of broilers, during 22-35 days of age (experiment I) and 33-43 days of age (experiment II). In both experiments, an increase in MCG induced a linear decline in glutamate dehydrogenase activity (p < 0.05). In contrast, increasing the concentration of SPGSO in the diet caused a linear increase in enzyme activity (p < 0.05). There was no (p > 0.05) isolated effect of glycerine on the enzyme activity in either evaluated phase; however, during 33-42 days of age, MCG inhibited (p < 0.05) the glutamate dehydrogenase activity by up to 34.43%. During 22-35 days of age, the diet containing SPGSO induced a higher protein content (p < 0.05) in the breast, and regardless of the source utilized, the maximum protein deposition was estimated (p < 0.05) when broilers were fed with 55.08 g glycerine/kg of diet. There was no (p > 0.05) interaction or isolated effects of the sources and levels of glycerine on the protein content in the breast of broilers at 33-42 days of age, and moreover, all diets containing glycerine promoted a similar protein deposition in the breast compared with birds that received the diet without glycerine. The bird age also showed to influence the feed intake and weight gain of broilers fed diet containing glycerine. It is concluded that for both rearing phases, an increase in glycerine in the diet did not necessarily reduce the glutamate dehydrogenase activity, and the protein deposition in the breast of broilers may not be strictly correlated with the activity of this enzyme.

Nitrogen, calcium and phosphorus balance of broilers fed diets with phytase and crystalline amino acids

Objetivou-se, com este trabalho, avaliar o efeito de racoes com reduzidos teores de proteina bruta (PB) e fosforo disponivel (Pd), suplementadas com fitase e aminoacidos, para frangos de corte na fase de crescimento (14 a 21 dias) e terminacao (35 a 42 dias de idade) sobre o balanco de nitrogenio, potassio e fosforo. Foram utilizados 90 pintos Cobb, distribuidos em um delineamento inteiramente casualizado com tres tratamentos e seis repeticoes, com cinco e tres aves por unidade experimental nas fases inicial e de crescimento, respectivamente. As racoes foram formuladas para conterem niveis reduzidos de PB e Pd (19 e 17% de PB na fase de crescimento, com 0,34% de Pd e 18 e 16% de PB na fase de terminacao, com 0,30% de Pd) e suplementadas com aminoacidos e 500 FTU de fitase/kg de racao Essas racoes foram, entao, que foram comparadas a uma racao controle (21% de PB e 0,46% de Pd para fase de crescimento e 19% de PB e 0,40% de Pd para fase de terminacao). A reducao da PB em quatro unidades percentuais reduziu a excrecao, e aumentou a retencao de nitrogenio, mostrando que a fitase nao interferiu no balanco de nitrogenio ao serem incluidos aminoacidos cristalinos nas racoes. A excrecao de potassio diminuiu em dietas com PB reduzida, mas esta reducao em excesso diminuiu a retencao deste elemento, exceto na fase de retirada. Conclui-se que racoes contendo niveis reduzidos de PB, calcio e fosforo, suplementadas com fitase e aminoacidos, sao eficientes em diminuir o poder poluente das excretas de frangos de corte.

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.

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.

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.