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.

No abstract

Nutritional value of corn with different qualities for broiler chickenABSTRACT -This work was carried out to determine the nutritional value of corn of different qualities, obtained by means of stratification in densimetric table, for broilers in different ages. The corns were designed as: MDA -high density corn; MDI -medium density corn; MDB -low density corn and MDT -total density corn, composed by 30% MDA, 60% MDI and 10% MDB. Two biological assays were carried out using the traditional total excreta collection method to determine the apparent metabolizable energy corrected by nitrogen balance (AME N ). The first assay was carried out using Cobb chicks with 11 to 19 days old and in the second assay, with chicks with 29 to 37 days old. Chemical analyses were made to estimate the nutritional profile, classification of the grains according to density and comparison by means of prediction equation estimatives the energy values and mycotoxins. The digestible amino acids profiles were obtained by NIR. The values of AME N of corns of different qualities (MDA, MDI, MDB and MDT) for broilers in initial phase were respectively: 3308; 3121; 2937 and 3239 kcal/kg; and broilers in growing phase were respectively: 3413, 3362, 3174 and 3348 kcal/kg. These results indicated significant energy losses of low density corn and the efficiency of the densimetric table to stratify the grains by quality. The different AME N values between birds ages suggest better energy utilization efficiency as age increases. The prediction equations could be used to estimate energy value of corn by its classification or density. However, the error associated to each prediction equation could compromise the accuracy of the nutritional value. The contaminations by aflatoxins and trichothecenes changed with quality of the stratified corn, important factor to be considered in the broilers feeding.

RESUMO -O objetivo do presente trabalho foi determinar as exigências de proteína para aves reprodutoras pesadas através do método fatorial. A exigência de proteína bruta para mantença (PBm) foi determinada por intermédio da técnica do balanço de nitrogênio por meio de ensaio de metabolismo com aves submetidas a quatro dietas com níveis decrescentes de proteína, proporcionando balanço positivo, próximo a zero e negativo. Para determinar a exigência de proteína bruta para o ganho de peso (PBg) dois experimentos foram conduzidos, sendo que em um, determinou-se as exigências líquidas de nitrogênio e no outro, a eficiência de utilização do nitrogênio para o ganho, por meio de abates semanais de aves no período de 26 a 33 semanas de idade. A exigência de proteína bruta para produção de ovos (PBo) foi determinada através de análises semanais de proteína bruta dos ovos coletados, no período de 31 a 37 semanas de idade, considerando a eficiência de deposição da proteína no ovo. A exigência e eficiência de utilização da proteína para mantença foram 2.282 mg PB/kg 0,75 /dia e 60,79%; respectivamente. As exigências de PBg e PBo determinadas foram: 356 mg PB/g e 262 mg PB/g, respectivamente, e as eficiências de utilização do nitrogênio, 40 e 46,80%, respectivamente. A equação de predição elaborada para aves reprodutoras pesadas na fase de produção foi: PB=2,282.P 0,75 +0,356.G+0,262.MO, onde PB é a exigência de proteína bruta (g/ave/dia), P o peso corporal (kg), G o ganho de peso (g/dia) e MO a massa de ovos (g/dia).Palavras-chave: balanço de nitrogênio, equação de predição, exigência de proteína, método fatorial, reprodutoras pesadas Prediction Equation of Crude Protein Requirements for Broiler Breeders HensABSTRACT -The objective of this study was to determine the protein requirement for broiler breeder hens using factorial method. The requirement of crude protein for maintenance (CPm) was determined using nitrogen balance technique in metabolism assay. The birds were fed with four protein levels in order to get a positive, a close to zero and a negative nitrogen balance. To determine the crude protein weight gain requirement (CPg), two experiments were carried out. The first was calculate to determine the net nitrogen requirement and the other to determine nitrogen use efficiency for body deposition, from 26 to 33 weeks old. The crude protein requirement for egg production (CPe) was determined by content of crude protein of eggs measured in birds from 31 to 37 weeks old. The protein requirement for maintenance was 2,282 mg CP/kg 0.75 /day and the protein efficiency 60.79%. The nitrogen requirement for weight gain and egg production were: 356 mgCP/g and 262 mg of CP/g, respectively, and the protein efficiency utilization were: 40 and 46.80% for weight gain and egg production, respectively. The prediction equation for broiler breeder hens was : CP = 2,282W 0.75 + 0.356G + 0.262 EM, where CP is crude protein requirement (g/bird/day), W is body weight (kg), G is weight gain (g/day) and EM is egg mass (g/day). ., v.31, n.3, p...

RESUMO -Um ensaio de metabolismo foi realizado para determinar os valores de EMV e EMVn da farinha integral de vagem de algaroba (FVA) com galos cecectomizados, utilizando o método Sibbald. Um experimento de desempenho foi realizado para avaliar os efeitos da inclusão da FVA em níveis de 0; 5; 10; 15; 20; 25; e 30% em rações peletizada e farelada para poedeiras comerciais. No experimento 1, foram obtidos valores de EMV e EMVn de 2819 e 2806 kcal, respectivamente, enquanto a FVA apresentou cinco vezes mais celulose e quatro vezes mais lignina em comparação com o milho. No experimento 2, verificou-se que a peletização aumentou o peso vivo, peso dos ovos e da clara e a porcentagem de clara e reduziu a porcentagem de gema. O nível de 30% da FVA reduziu o peso e a massa de ovos e piorou a conversão alimentar, em comparação ao tratamento controle. Houve efeito quadrático do nível da FVA (como efeito principal) sobre o consumo de ração, a produção de ovos, massa de ovos, conversão alimentar por massa e porcentagens de casca, clara e gema. O consumo da FVA cresceu linearmente nas rações peletizada e farelada em resposta ao seu aumento na ração. A inclusão da FVA até 13,6%, em substituição ao milho, em rações isoprotéicas e isoenergéticas não afetou adversamente o desempenho de poedeiras comerciais. Palavras-chave: fibra dietética, desempenho, valores energéticos Energy Values and Effects of Integral Mesquite Pods (Prosopis juliflora (Sw.) D.C.) Meal Inclusion in Commercial Laying Hens DietsABSTRACT -An experiment was carried out to determine TME and TMEn values of integral mesquite pods meal (MPM) in cecectomized cockerels by Sibbald method. A second experiment was conducted to examine the effects of MPM inclusion (0, 5, 10, 15, 20, 25 and 30%) in pelleted and mashed diets on laying hens performance. In the experiment 1, values of TME and TMEn in raw MPM were 2819 and 2806 kcal/kg, respectively, while cellulose and lignin contents were five-and four-fold higher than in corn. Results of experiment 2 showed that pelleting increased live weight, egg and albumen weight and percentage of albumen, and reduced yolk percentage. The 30% MPM level reduced egg and mass weights and affected feed to egg mass ratio when compared to control. There was quadratic effect of MPM levels (as main effect) on feed intake, egg production, egg mass, feed to egg mass ratio, and the percentages of shell, albumen and yolk. The MPM intake increased linearly according to their diet addition level. The inclusion of MPM up to 13.6% in isonitrogen and isoenergy diets did not adversely affect laying hens performance.