Carlos Bôa-Viagem Rabello

Exigências energéticas para mantença e para o crescimento de frangos de corte

This work was conducted to determine the energy requirements for broilers using the factorial method. The metabolizable energy (ME) requirements for maintenance (MEm) were determined at 13, 23 and 32oC (±2 C) by the comparative slaughter technique. ME requirements for weight gain were estimated considering the net efficiency of energy utilization for growth and body energy content. The energy requirements for maintenance were of 159.36, 116.17, and 128.66 kcal/kg0.75/day at 13, 23, and 32oC, respectively, and quadratic effect of temperature (T) on the maintenance requirement (MEm=300.14 - 14.61 T + 0.2876 T2, r2=0.90) was detected. Metabolizable energy requirements for weight gain for males and females were of 3.72 and 3.98; 4.21 and 3.93; 4.51 and 7.04 kcal/g, for the periods from 1 to 21, 22 to 42 and 43 to 56 days of age, respectively. Considering the requirements, prediction models were designed for ME requirements using adjustments for body weight, daily weight gain and temperature. The models predicted the ME requirements for broilers as redult of from breed manual recommendations and the studied models.

Equações de predição das exigências protéicas para frangos de corte

The objective of this study was to determine prediction equations for crude protein (CP) requirements for males and females broilers using the factorial method. In order to determine the crude protein for the maintenance was used the nitrogen balance technique. The crude protein requirements for weight gain were determined based on body nitrogen content and nitrogen utilization efficiency for the diet. Considering the requirements for maintenance and weight gain were elaborated prediction equations for CP requirements (g/bird/day) for males broilers (7 to 21 days - PB = 1.323xW0.75 + 0.256xG, 22 to 42 days - PB = 1.323xW0.75 + 0.277xG, and 43 to 56 days - PB = 1.323xW0.75 + 0.283xG) and females (7 to 21 days - PB = 1.748xW0.75 + 0.258xG, 22 to 42 days - PB = 1.748xW0.75 + 0.274xG, and 43 a 56 days - PB = 1.748xW0.75 + 0.300xG) where W = body weight (kg) and G = daily weight gain (g/day). The prediction equations utilization is recommended to determine the minimal nitrogen or crude protein requirements considering the amino acid requirements.

Modelling energy utilization in poultry

Models of daily energy requirement can help to establish better and more profitable feeding programs for poultry. Studies have been conducted at UNESP-Jaboticabal-Brazil with the aim of studying energy utilization in broiler breeders, laying hens, and broilers, and to establish metabolisable energy requirement models. The factorial approach was used to partition the energy requirements into maintenance, growth, and production components. The resulting models consider body weight, weight gain, egg production, and environmental temperature for the determination of the energy requirements of poultry. These models were evaluated in performance trials and provided good estimates. Therefore, they can be used to establish nutritional programs. The aim of this chapter is to describe the development of these models and to outline the results of our studies at UNESP.

Programas de alimentação para matrizes pesadas após o pico de postura, com base em modelos para predizer a exigência energética

This research was carried out to evaluate the performance of broiler breeder hens submitted to different feeding programs applying models to predict the metabolizable energy requirements after peak production. The experiment was conducted during 84 days (three periods of 28 days), at the Sao Paulo State University - Jaboticabal. Seven hundred and forty female broiler breeders Hubbard Hy-Yield, and eighty males Petterson 55-week old were assigned to a randomized design with four treatments and five replicates of 37 birds (box), and a factorial model 4´3 (four treatments and three periods). The feeding programs evaluated were: T1 - feeding according to the lineage recommendation (428 kcal/bird/day from 55 to 66-weeks old); T2 - energy reduction (2 kcal/bird/day for each week); T3 - feeding according to UNESP (2000) model; T4 - feeding according to NRC (1994) Model. The feeding program with weekly energy reduction was suitable to maintain the productive and reproductive performance of the birds, indicating the possibility of reducing 2 kcal/bird/day, at each week, in broiler breeders fed after 55 weeks of age. The UNESP and NRC models promoted higher energy intakes than the lineage recommendation, probably due to the body weight of breeders, that were above the recommended for lineage, providing higher energy requirements of maintenance.

Efeito do Uso de Diferentes Níveis de Inclusão de Glicose de Milho em Rações Peletizadas Sobre o Desempenho de Pintos de Corte de 1 a 7 Dias

A utilizacao das reservas vitelinicas associado a ingestao de carboidratos logo apos o nascimento do pintainho pode refletir em um bom desempenho. Portanto, objetivou-se avaliar o uso de diferentes niveis de inclusao de xarope de glucose sobre o desempenho de pintos de corte na fase preinicial. Os tratamentos consistiram de cinco racoes peletizadas: uma com a inclusao de 0% do ingrediente e quatro racoes com 3; 6; 9 e 12% de inclusao, totalizando cinco tratamentos e seis repeticoes com 10 aves por unidade experimental, com peso inicial medio de 46 g. Nao houve efeito significativo para o consumo de racao nos tres modelos de regressao estudados: Linear; quadratico e Sigmoidal. Quando analisado os dados de ganho de peso e conversao alimentar pelos tres modelos de regressao, estes apresentaram efeito significativo, porem a determinacao do melhor modelo foi realizada atraves do r2 ajustado, para ambos os dados quanto maior o nivel de inclusao de xarope de glicose de milho, menor o ganho de peso e maior a conversao alimentar. Verificou-se assim, a viabilidade de inclusao de 2,18% para ganho de peso e 4,52% para conversao alimentar. DOI: 10.15528/2176-4158/rcpa.v14n1p58-61