Uso do ácido orgânico (ácido fumárico) nas rações de frangos de corte

This experiment was carried out to evaluate the effect of the addition of fumaric acid to broiler diet on birds performance. One thousand and eighty Hubbard day-old broiler chicks were alloted in a randomized block design, six treatments with two replicates of males, and four replicates of females. Three basal diets were formulated to meet the nutritional requirements in each growing phase: from 1 to 21 days, 21 to 37 days and 37 to 45 days. Treatments consisted first in the addition of growth promoter to 0.75 and 1.0%, of fumaric acid. The group treated without of both growth promoter and fumaric acid presented a higher intake and a smaller feed:gain ratio in relation to the fumaric acid treated groups. However, there were no differences among groups treated with growth promoter and fumaric acid. The contrasts did not show any difference among weight gain, carcass yield and abdominal fat. The addition of fumaric acid levels to the diets promoted reduction of feed intake, without any effect on weight gain, improving, therefore, the feed/gain ratio. A digestibility experiment was carried out, using 30 Hy-Line roosters, to determine apparent metabolyzed energy (AME), corrected by nitrogen of the diets containing 0.0, 0.5 and 1.0% of the acid. An increase on the AME of the diets was observed with fumaric acid addition

Combination of M-Estimators and Neural Network Model to Analyze Inside/Outside Bark Tree Diameters

Part 1: ANN-Classification and Pattern RecognitionInternational audienceOne of the most important statistical tools is linear regression analysis for many fields such as medical sciences, social sciences, econometrics and more. Regression techniques are commonly used for modelling the relationship between response variables and explanatory variables. In this study, inside bark tree diameter was used as the dependent variable and outside bark diameter and site type as independents. While generally it is assumed that inside and outside bark diameters are linearly correlated, linear regression application is weak in the presence of outliers. The purpose of this study was to develop a Multi-Layer Perceptron neural network model which considered significant variables from an a priori developed robust regression model. The application of robust regression could be considered in selecting the input variables in a neural network model

Programas de alimentação para matrizes pesadas após o pico de postura, com base em modelos para predizer a exigência energética Feeding programs for broiler breeder hens after peak production based on models to predict energy requirements

Este trabalho foi conduzido com o objetivo de avaliar o desempenho de matrizes pesadas, submetidas a diferentes programas de alimentação estabelecidos pela aplicação de modelos para predizer as exigências energéticas, após o pico de postura. O experimento foi conduzido no setor de avicultura da UNESP Campus Jaboticabal, com duração de 84 dias (três períodos de 28 dias). Foram utilizadas 740 matrizes de corte Hubbard Hy-Yield e 80 machos Petterson, com 55 semanas de idade. O delineamento foi inteiramente casualizado, com quatro tratamentos e cinco repetições de 37 aves por repetição (box) e um modelo fatorial 4´3 (quatro tratamentos ´ três períodos). Os programas de alimentação avaliados foram: T1 - Fornecimento de ração de acordo com o padrão da linhagem (428 kcal/ave/dia de 55 a 66 semanas de idade); T2 - Redução semanal de energia (2 kcal de EM/ave em cada semana); T3 - Fornecimento de ração de acordo com o modelo de exigência de EM, UNESP (2000); e T4 - Fornecimento de ração de acordo com o modelo, NRC (1994). O programa de alimentação com redução semanal de energia foi adequado para manter os desempenhos produtivo e reprodutivo das aves, indicando a possibilidade de redução de 2 kcal/ave/dia, em cada semana, na alimentação de matrizes pesadas após 55 semanas de idade. Os modelos UNESP e NRC proporcionaram estimativas mais elevadas das exigências energéticas que o modelo padrão, provavelmente em decorrência do ganho de peso das matrizes, que esteve acima do recomendado para a linhagem, promovendo maiores exigências de energia para mantença.<br>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