Valores energéticos de rações expandidas em diferentes temperaturas para frangos de corte / Energy values of expander feed in different temperatures for broilers

O objetivo deste estudo foi determinar os valores energéticos de rações expandidas, obtidas em diferentes temperaturas de expansão para frangos de corte em diferentes idades. As rações foram expandidas nas temperaturas: 80; 100; 120; 140ºC. Dois ensaios biológicos foram conduzidos utilizando-se o método tradicional de coleta total de excretas para determinar a energia metabolizável aparente corrigida (EMAn). Os ensaios metabólicos foram conduzidos com pintos machos Cobb, de 11 a 19 dias (fase inicial) e de 27 a 35 dias de idade (fase de crescimento), utilizando-se as mesmas aves do primeiro ensaio e, assim, preservando os tratamentos a que foram submetidas. Os valores da EMAn das rações da fase inicial foram: 2937; 2900; 2806 e 2751kcal/kg, e da fase de crescimento: 3045; 3031; 3115 e 2977kcal/kg, respectivamente. Os resultados mostraram uma redução linear dos níveis de EMn com o aumento da temperatura de expansão na idade de 11 a 19 dias. As perdas relativas entre as rações expandidas a 80 e 100ºC foram mínimas, enquanto nas temperaturas de 120 e 140ºC foram significativamente superiores. No ensaio de metabolismo para a fase de crescimento, verificou-se que as perdas relativas entre as rações expandidas a 80 e 100ºC foram pequenas (-14kcal). Para a ração expandida a 120ºC, o valor energético foi superior (84 kcal), enquanto para 140ºC foi significativamente inferior (-138kcal). Esses resultados mostram que, na fase de crescimento, os frangos de corte maximizaram o aproveitamento energético das rações na temperatura de expansão de 120ºC e que, em temperaturas acima desse nível, ocorrem altas perdas da EMAn das rações, que podem comprometer o consumo, a deposição de proteína e a conversão alimentar e, consequentemente, trazer grandes prejuízos econômicos pelo menos à idade de abate. As temperaturas de expansão de rações entre 80 e 100ºC apresentaram os melhores valores de EMAn para frangos com idade entre 15 e 10 dias, enquanto para idade de 31 a 35 dias foi de 120ºC.(AU)

The aim of this study was to determine the energetic value of feed in different expansion temperatures for broilers of different ages. The feedexpanded in the following temperatures: 80; 100, 120 and 140ºC. Two biological assays were run to establish apparent metabolizable energy corrected by nitrogen balance (AMEN) using the traditional total excreta collection method. In the first assay Cobb chicks were used from 11 to 19 days of age (initial period), and 29 to 37 days of age (growth period), as well as the same treatments of the first assay. The AMEN values for the initial period were respectively: 2937, 2900, 2806 and 2751 kcal/kg; and broilers in growing period were respectively: 3045, 3031, 3115 and 2977 kcal/kg. The results showed a linear decrease of the levels EMAN with an increase of the temperature of expansion from 11 to 19 days old. The loss relation between feed expanded at 80 and 100ºC were minimal, while in temperatures between 120 and 140ºC they were significantly higher. In the metabolic assay for period growth, we observed that the relation of energy values between feed expanded at 80 and 100ºC were smaller (14 kcal), while for the expanded in 120ºC they were superior (84 kcal), and at 140ºC were inferior (138 kcal). These results suggest greater energy utilization efficiency in period growth at a temperature of 120 ºC, while in temperatures above of this level there was greater loss of EMAN in feeds, which can prejudice feed intake, protein deposition and feed conversion, and consequently damage economics by increasing slaughter age. The expansion temperatures in feed between 80 and 100ºC showed the best EMAN values for broilers with 15 - 19 days of age, while for 31 - 35 days old it was 120 ºC.(AU)

Valores nutricionais do milho de diferentes qualidades para frangas de reposição na fase de recria / Nutritional value of corn with different qualities for egg pullets in the growing phase

O experimento objetivou determinar os valores nutricionais de diferentes frações de milho obtidas por meio de estratificação em mesa densimétrica na recria de frangas. Os milhos foram designados como: MDA - milho de densidade alta; MDI - milho de densidade intermediária; MDB - milho de densidade baixa; MDT - milho de densidade total, composto de 30% de MDA, 60% de MDI e 10% de MDB. Para a determinação da energia metabolizável corrigida (EMAn) foi utilizado o método de coleta total de excretas em frangas Hy Line de 15 semanas. Os valores de EMAn (kcal/kg na MN) foram: 3.467; 3.340; 3.217 e 3.385kcal/kg e densidade (kg/m³): 818,61; 698,13; 681,80 e 736,39kg/m³ para MDA; MDI; MDB e MDT, respectivamente. O MDB apresentou maior valor em todos os aminoácidos digestíveis, com maior intensidade para o triptofano. As frações de milho foram variáveis quanto ao EMAn e perfil de aminoácidos digestíveis, indicando a necessidade de correções nutricionais para a formulação de rações de custo mínimo...

The experiment aimed to determine the nutritional value of different corn fractions obtained by stratification in a gravity table of replacement pullets. The corn was designated as MDA - high density corn; MDI - medium density corn; MDB - low density corn; MDT - total corn density, composed of 30% MDA, 60% MDI and 10% MDB. To determine the corrected metabolizable energy (AME N) a method for total collection of excreta with pullets Hy Line was used for 15 weeks. AME N (kcal/kg in MN) were: 3467, 3340, 3217 and 3385kcal/kg and density (kg/m³): 818.61, 698.13, 681.80 and 736.39 for MDA, MDI, MDB and MDT, respectively. The MDB showed the highest value in all the digestible amino acids, with higher intensity for the tryptophan. The fractions of corn were variable as to AME N and digestible amino acid profiles, indicating the need for corrections to the nutritional feed formulation of minimum cost...

Balanço eletrolítico da dieta e desempenho de frangos em condições naturais de estresse calórico / Electrolyte balance of diets under performance of broiler in naturals conditions of heat stress

Avaliou-se o efeito da suplementação de eletrólitos sobre o desempenho de frangos, utilizando bicarbonato de sódio (NaHCO3) e cloreto de potássio (KCl) para ajuste do balanço eletrolítico da dieta (BED) com duas porcentagens de proteína bruta (PB). Utilizaram-se 800 frangos machos, alojados em 20 boxes, distribuídos em delineamento inteiramente ao acaso, com quatro tratamentos, cinco repetições e 40 aves por unidade experimental. Os tratamentos foram: dieta basal; dieta sem redução de PB suplementada com eletrólitos para ajuste do BED para 250mEq/kg; dieta com redução de PB, sem suplementação de eletrólitos; e dieta com redução de PB, com eletrólitos para ajuste do BED para 250mEq/kg. Foram avaliados: consumo da dieta, peso final, ganho de peso, ganho de peso médio diário, conversão alimentar e calórica e eficiência de utilização de nitrogênio e lisina nas fases de sete a 21 e de sete a 42 dias. Não se observaram diferenças (P>0,05) no consumo da dieta. A correção do BED com menor teor de PB melhorou (P<0,05) o peso final, na fase inicial. Houve piora (P<0,05) no ganho de peso e na conversão alimentar nas duas fases. A redução de três pontos percentuais na PB da dieta piorou o desempenho dos frangos.

The effect of the supplementation of electrolytes on de performance of broilers using sodium bicarbonate (NaHCO3) and potassium chloride (KC1) to adjust the electrolytic balance of the diet (BED) with two percentages of raw protein (PB) was studied. 800 male broiler chickens, housed in 20 boxes, distributed in random lineation, with four treatments, five repetitions and 40 birds per experimental unit were used. The treatments were: base diet; diet with no reduction of PB supplemented with electrolytes to adjust BED to 250mEq/kg; diet with a reduction of PB, with no electrolyte supplementation; and diet with the reduction of PB, with electrolytes to adjust the BED to 250mEq/kg. What was evaluated was: diet consumption, final weight, weight gain, average daily weight gain, food conversion and caloric efficiency of the use of nitrogen and lysine in phases from 7 to 21 and 7 to 42 days. No differences were observed (P>0.05) in diet consumption. The correlation of BED with the lower percentage of PB improved (P<0.05) the final weight in the initial phase. Weight gain and food conversion worsened (P<0.05) in both phases. The reduction of three percentage points in the PB in the diet worsened the broiler chicken's performance.

Modelling energy utilisation in broiler breeder hens.

1. The objective of this study was to determine a metabolisable energy (ME) requirement model for broiler breeder hens. The influence of temperature on ME requirements for maintenance was determined in experiments conducted in three environmental rooms with temperatures kept constant at 13, 21 and 30 degrees C using a comparative slaughter technique. The energy requirements for weight gain were determined based upon body energy content and efficiency of energy utilisation for weight gain. The energy requirements for egg production were determined on the basis of egg energy content and efficiency of energy deposition in the eggs. 2. The following model was developed using these results: ME = kgW0.75(806.53-26.45T + 0.50T2) + 31.90G + 10.04EM, where kgW0.75 is body weight (kg) raised to the power 0.75, T is temperature ( degrees C), G is weight gain (g) and EM is egg mass (g). 3. A feeding trial was conducted using 400 Hubbard Hi-Yield broiler breeder hens and 40 Peterson males from 31 to 46 weeks of age in order to compare use of the model with a recommended feeding programme for this strain of bird. The application of the model in breeder hens provided good productive and reproductive performance and better results in feed and energy conversion than in hens fed according to strain recommendation. In conclusion, the model evaluated predicted an ME intake which matched breeder hens' requirements.

Modeling metabolizable energy utilization in broiler breeder pullets.

The objective of this study was to determine models for ME requirements for broiler breeder pullets using the factorial method. The influence of the temperature on maintenance ME requirements was determined by experiments conducted in three environmental rooms with temperature kept constant at 15,22, and 30 degrees C, using the comparative slaughter technique. The energy requirements for weight gain were determined based on the body energy content and efficiency of energy utilization for weight gain. Two ME requirement models for each age were developed using the coefficients for maintenance and weight gain. The models for 3 to 8 wk were ME = W(0.75) (186.52 - 1.94T) + 2.47WG, and ME = W(0.75) (174 - 1.88T) + 2.83WG; for 9 to 14 wk, ME = W(0.75) (186.52 - 1.94T) + 2.69WG, and ME = W(0.75) (174 - 1.88T) + 2.50WG; and 15 to 20 wk, ME = W(0.75) (186.52 - 1.94T) + 2.76WG, and ME = W(0.75) (174 - 1.88T) + 3.24WG. In these equations, W is BW (kg), T is temperature (degrees C), and WG is daily weight gain (g). These models were compared to the breeder's recommendations in a feeding trial from 5 to 20 wk of age. Models 1 and 2 provided energy intakes that promoted BW smaller than the breeder's recommendation. However, all breeder pullets had weights above the standard recommendation. Model 2 gave the smallest ME intake and BW close to the standard recommendation and provided the best prediction of ME requirements.