ABSTRACT The objective of this study was to determine the chemical composition, non-starch polysaccharides (NSP) content, in vitro digestibility of starch, apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and apparent and apparent nitrogen-corrected coefficient of metabolizable energy (ACME and ACMEn) of three corn hybrids dried at different temperatures in the diets of broiler chickens. The energetic values were determined by the total collection of excreta method, using broilers from 11 to 21 d, placed in a completely randomized design in a factorial scheme (three corn hybrids and two drying temperatures: 80 and 110 °C), totalizing six treatments, seven replicates, and four birds/replicate. The data were subjected to two-way ANOVA. There was an interaction between the two factors tested wherein the AME and AMEn were increased when using corn Hybrid 1 dried at 80 °C. As main effects, the use of corn Hybrid 3 increased ACME and ACMEn. The drying temperature of 110 °C increased amylose, resistant starch, and nitrogen bound to the fiber contents, and reduced soluble:total NSP ratio. These changes may be responsible for the differences in digestibility of nutrients. The mean values of AME and AMEn of corn dried at 80 and 110 °C were 14.03 and 13.84 MJ/kg, respectively, and 81.62 and 80.53% for ACME and ACMEn, respectively.

Objetivou-se avaliar o desempenho, glicerol sérico e umidade da cama de pintos de corte recebendo rações com diferentes níveis e fontes de glicerina. Foram utilizados 1300 pintos de corte machos Cobb 500, num arranjo fatorial 4x3+1, com delineamento inteiramente casualizados, sendo quatro níveis de inclusão (17,5; 35,0; 52,5 e 70,0g/kg) de três 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 níveis de glicerina foram teste de Student-Newman-Keuls e análise de regressão, respectivamente; e para o tratamento, teste de Dunnett. Utilizou-se quatro repetições e 25 aves por parcela. O consumo de ração foi influenciado (P<0,05) pelas fontes de glicerina, sendo a GM a fonte que promoveu menor consumo nas aves, porém, não houve diferença dos tratamentos em relação ao controle. Não houve diferença significativa para o ganho de peso. Houve interação dos níveis e fontes de glicerina para a conversão alimentar. Para a GS, a melhor conversão alimentar com a inclusão de 50,35g; para a GM, houve uma piora linear com o aumento da inclusão de glicerina. Houve interação para a concentração de glicerol sérico nas aves, obtendo aumento linear nas aves que ingeriram a GS e GPUR, e redução 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 incluídas nas rações para pintos de corte até 70,0g/kg, sem prejudicar o desempenho dos animais.

This work aimed to evaluate the performance, serum glycerol and litter moisture of 1300 male Cobb 500 chicks fed diets containing different levels and sources of glycerin. A 4x3+1 factorial arrangement of treatments in a completely randomized design was used, with four inclusion levels of three glycerine (crude soybean (GS), gross mixed (GM) and semipurified (GPUR)) on isonutrient diets and one control treatment without glycerin. The methods of Student-Newman-Keuls test and regression analysis were applied for sources and levels of glycerin, respectively; and Dunnett test for treatment. It was used four replicates and 25 chickens per pen. Feed intake was affected (P <0.05) by the sources of glycerin, and GM was the source that promoted lower consumption in birds, however, there was no difference in the treatments when compared to control. Also there was no significant difference in weight gain. An interaction of levels and sources of glycerine to the feed conversion was seen.GS had the best feed conversion with the inclusion of 50,35g; GM had a linear worsening with increasing addition of glycerin. There was an interaction for the concentration of serum glycerol in birds, obtaining linear increase in birds consuming the GS and GPUR, and linear decrease for GM. The gain of litter moisture was influenced by the sources of glycerin, with a lower humidity for GM. The glycerine studied may be included in diets for broiler chicks until 70,0g/kg, without harming animal performance.

O objetivo deste trabalho foi avaliar o uso de valores de equivalência da fitase como base para redução de fósforo disponível (P-disp) em dietas para frangos. Foram avaliados dez planos nutricionais com seis repetições de 15 aves cada uma. Avaliaram-se: desempenho, teor de cinzas na tíbia e custo da ração. De 1 a 7 e de 36 a 42 dias de idade, as aves receberam dieta basal; de 8 a 21 dias, dieta sem fitase contendo 3,9 g kg-1 de P-disp e quatro dietas com fitase contendo de 1,1 a 2,5 g kg-1 de P-disp; e de 22 a 35 dias, dieta sem fitase contendo 3,4 g kg-1 de P-disp mais dieta com fitase contendo 1,6 g kg-1 de P-disp. O melhor plano nutricional foi composto pelas dietas: 4,7 g kg-1 de P-disp sem fitase (1 a 7 dias); 2,0 g kg-1 de P-disp suplementada com fitase (8 a 21 dias); 3,4 g kg-1 de P-disp em ração sem fitase (22 a 35 dias); e 3,0 g kg-1 de P-disp em ração sem fitase (36 a 42 dias). A redução do P-disp ocorre no período de 8 a 21 dias de idade e corresponde a 2,0 g kg-1 de ração suplementada com 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.

A redução do teor de fósforo disponível (Pdisp) na dieta de frangos deve ser acompanhada de adequada suplementação da fitase. Um experimento foi conduzido com frangos de corte, no período de 15 a 28 dias de idade, para determinar o nível de fitase necessário quando a ração farelada é formulada com 0,213% de Pdisp para permitir resultados de desempenho, teor de cinzas na tíbia e aproveitamento do cálcio (Ca) semelhantes ao determinado para aves alimentadas com uma dieta formulada para atender suas exigências nutricionais. Desse modo, 120 frangos foram distribuídos em esquema fatorial (4+1) x2, correspondendo a quatro rações deficientes em Pdisp (0,213%) suplementadas com fitase (0; 750; 1.500 ou 2.250FTU kg-1) mais uma ração controle positivo sem fitase (0,426% de Pdisp), fornecidas a frangos machos e fêmeas. Os machos apresentaram melhor desempenho e maior retenção de Ptotal. A redução do teor de Pdisp da dieta sem o uso de fitase piorou o desempenho, o teor de cinzas ósseas e a retenção do Ca, todavia, esses parâmetros foram gradativamente melhorados com o aumento do nível de fitase na ração. Independente do sexo, ao utilizar 2.250FTU kg-1, é possível reduzir o teor de Pdisp para 0,213% sem prejudicar o desempenho, teor de cinzas na tíbia e a retenção do Ca, além de reduzir a excreção do Ptotal em 56,75% e melhorar seu aproveitamento em 38,58%.

The reduction of the available phosphorus (avP) content in the broiler diet must be followed by the supplementation of adequate phytase. One experiment was conducted with broilers from 15 to 28 days of age to determine the level of necessary phytase when the mashed diet is formulated with 0.213% of avP to enable the results of performance, tibia ash content, and calcium (Ca) utilization similar to those determined for birds fed with diet formulated to meet their nutritional requirements. Thus, 120 broilers were distributed in (4+1) x2 factorial arrangement corresponding to four deficient diets in avP (0.213%) supplemented with phytase (0; 750; 1,500 or 2,250FTU kg-1) plus one positive control diet without phytase (0.426% of avP), supplied to male and female broilers. Males showed better performance and higher totalP retention. Decrease in the avP content of the diet without phytase use worsened the performance, tibia ash content, and Ca retention; however, these parameters were improved gradually with the increase of the phytase level in the diet. Regardless of sex, using 2,250FTU kg-1, it is possible to reduce the avP to 0.213% without impairing performance, tibia ash content, and Ca retention; in addition to reducing the totalP excretion in 56.75% and improving its utilization in 38.58%.