Antonio Augusto Domingos Coelho

Influência do sistema de criação sobre o desempenho, a condição fisiológica e o comportamento de linhagens de frangos para corte

The objectives of this research were to evaluate the influence of rearing systems (intensive or semi-intensive) on the performance (body weight and feed efficiency), chicken physiological condition under heat stress (rectal temperature, respiratory frequency and hematocrit) and behavioural parameters (frequency in the pasture areas) of broilers lines. To evaluate broilers performance and physiological condition on the ages of 45, 55, 65 and 75 days one experiment was carried out in boxes with 4,5 m2 of inside area and 35 m2 of outside area were 35 broilers were reared in each box. Another experiment was carried out to evaluate the frequency of broilers it the pasture areas from 35 to 75 days of age. One of the evaluated lines did not show adaptation to the semi-intensive rearing system. Significant differences were found in broilers performance and physiological conditions in both systems. In the semi-intensive rearing system the rectal temperature, respiratory frequency, hematocrit and feed efficiency were smaller and body weight larger than in the intensive rearing system. It was concluded that the semi-intensive rearing system provided conditions that increased broilers welfare and positively influenced the physiological conditions and performance of the broilers.

Polymorphism analysis of the hsp70 stress gene in Broiler chickens (Gallus gallus) of different breeds

The promoter region and the beginning of the coding region of the hsp70 stress gene were analysed in broiler chickens of a commercial breed (Hubbard-Pettersen), a breed selected for weight gain (PP1) and a non-selected breed (naked-neck Label Rouge). The naked neck gene (Naked neck, Na), which reduces feathering in birds and is thus related to heat resistance, was present in both PP1 and Label Rouge breeds. Genomic DNA was restricted with PstI and Southern blotting analysis of the samples revealed the absence of polymorphic sites for that enzyme in the promoter region and beginning of the coding region of the hsp70 gene of studied birds. PCR-SSCP analysis of these regions, however, indicated the presence of polymorphisms in the beginning of the coding region and the sequencing of the PCR products confirmed and identified two polymorphic sites in this region: a transition A ® G in position +258 and a transversion C ® G in position +276. Both mutations were considered to be silent, since they did not modify the aminoacid sequence of the protein Hsp70. The promoter region of the hsp70 gene was identical in all studied birds, indicating that the regulation pattern of this gene must be the same in all birds at the promoter region. Three different alleles (hsp70-1, hsp70-2 and hsp70-3) were identified for the hsp70 gene from the observed mutations. The allele hsp70-3 was detected in only two breeds, Hubbard-Pettersen and PP1, but at a low frequency (0,016 and 0,006, respectively).

Avaliação do estresse térmico em condição simulada de transporte de frangos de corte

This experiment aimed to simulate thermal-stress-environment conditions in climatic chamber during the transportation of birds to slaughterhouse to evaluate the influence of these conditions on physiological parameters and carcass conformation in broiler chickens. Thirty chicks with 42 days old were weighted and distributed to transportation crates (10 chicks by crate), and submitted to high stress conditions (35oC and 85% RH) to simulate the transport to the slaughterhouse. At each time of exposition to the stress conditions (0, 30, 60, 90 and 120 minutes), two birds from each crate was withdrawn for further analyses. Body weight, rectal temperature, respiratory frequency and hematocrit value were measured, and after that they were slaughtered to evaluate of carcass conformation (carcass, breast, legs (thighs and drumsticks), back and viscera weights). Physiological and carcass conformation characteristics (body weight loss and legs weight, wings and back weights) differed after be submitted to high stress conditions. The exposition time and the environment conditions of transport affected negatively the metabolism and thermal body equilibrium of broilers.

Coloração de cortes cozidos de frangos alimentados com urucum

Para atender as necessidades do mercado consumidor e, assim, agregar valor ao seu produto, a industria avicola tem procurado formas de se ajustar a esse padrao. Sendo o urucum um excelente pigmentante, este trabalho teve como objetivo avaliar o comportamento do corante na carne de frango cozida. Cem animais foram divididos em quatro grupos e tratados com 0; 1; 2; e 3% de urucum incluso na racao. Para avaliacao da coloracao dos cortes, foi utilizado o sistema Hunter Lab. Para o parâmetro L, os cortes de peito foram inversamente proporcionais aos cortes de coxa, diminuindo, conforme aumento da porcentagem de urucum para peito, e aumentando, para coxa. Para o parâmetro Croma, os cortes apresentaram comportamento semelhante, aumentando, conforme aumentou a porcentagem de urucum. Os demais parâmetros (a, b e Hue-Angle) nao tiveram diferencas significativas. Portanto, a utilizacao de urucum, com a intencao de aumentar a pigmentacao da carne frangos, aumenta conforme aumenta a porcentagem de urucum na racao dos animais.

Síndrome ascítica em frangos de corte: uma revisão sobre a fisiologia, avaliação e perspectivas

Poultry genetic breeding programs which look for maximum weight gain, improved feed conversion, high viability, high carcass yield and low fat deposition may cause some physiologic syndromes, for example caloric stress, sudden death and ascites. Ascites is framed in concept of the multifactorial syndromes, once its manifestation happens when certain genetic and environment factors act together, determining the process. Anatomical and physiological limitations in blood circulation in the lungs give rise to pulmonary hypertension syndrome (PHS), producing great fluid accumulation in abdominal cavity, which is denominated ascites. Ascites causes reduction of blood circulation efficiency, leading broilers to death due to hypoxia, mainly between 30 and 40 days of age. Ascitic broilers have reduced body weight gain as a consequence of feed restriction. Additionally, there is increased abdominal cavity volume and internal organ congestion. Ascites is discussed through this manuscript based on physiological description, evaluation measures and perspectives.

Avaliação de materiais genéticos visando à produção de frango caipira em diferentes sistemas de alimentação

The aim of the current study was to evaluate the performance of experimental and commercial genotypes of chicken recommended for free-range rearing system submitted to two diet programs (conventional and alternative). The experimental design consisted of a randomized design applied until 28 days and a randomized factorial 8x2 design (eight genotypes: Paraiso Pedres, Caipirao da ESALQ, 7 P, Embrapa 041, Label Rouge, Paraiso Pelado, Caipirinha da ESALQ and Carijo Barbada and two diet programs), using two replicates with 30 chickens/box as experimental unit, from 29 to 84 days of age. Average body weight and feed:gain ratio were recorded during three periods: 1) 0-28, 2) 0-56 and 3) 0-84 days and submitted to the analysis of variance. The effect of diet was evidenced for all traits in periods 2 and 3. The effect of genotype was verified for all variables in period 1, but only for average body weight in periods 2 and 3. The interaction genotype and diet was observed for feed:gain ratio in period 2 and for all traits in period 3. Paraiso Pedres and Caipirao from ESALQ presented higher average body weight than the other genotypes in period 1. In period 2, Paraiso Pedres presented the highest average body weight and all genotypes differed for feed:gain ratio. Caipirao from ESALQ, Paraiso Pedres and 7 P presented higher average body weight than the other genotypes and all strains differed for feed:gain ratio in period 3. The full substitution of conventional diet by corn led to a worse chicken performance. Overall performance of the evaluated genotypes was conditioned by genetic and nutrition factors, with the lowest negative effects of substitution of conventional diet by corn on all traits in the Paraiso Pedres genotype.

Efeito de Bixa orellana na alteração de características de ovos de galinhas

Objetivou-se, no presente trabalho, avaliar os efeitos da adicao de urucum (Bixa orellana L.) na racao de galinhas poedeiras, quanto a possivel interferencia na qualidade dos ovos. Para obtencao das amostras foram utilizados 125 animais, divididos em cinco tratamentos: Controle (0% - T1) e quatro tratamentos com adicao de urucum na racao (0,5% - T2; 1,0% - T3; 1,5% - T4 e 2,0% - T5). Os animais foram separados aleatoriamente em cinco blocos de cinco animais, totalizando 25 animais por parcela. Os ovos, apos coletados, foram classificados usando ovoscopio, pesados, realizada analise de gravidade especifica, unidade Haugh, altura de albumen e gema, espessura da casca, diâmetro e indice de gema. As diferentes dietas nao afetaram: peso; gravidade especifica; altura do albumen; espessura da casca; altura de gema; diâmetro de gema. Pode ser observado que a adicao de urucum, na racao de poedeiras, nao alterou a maior parte dos parâmetros de qualidade fisica do ovo, somente a unidade Haugh e o indice de gema apresentaram diferenca (p<0,05).

Viscosity of egg white from hens of different strains fed with commercial and natural additives

A coloracao da gema, transparencia e viscosidade da clara (albumen) sao parâmetros importantes que os consumidores consideram na avaliacao dos ovos. O objetivo do estudo foi verificar as trocas que ocorrem na armazenagem por 36 dias em relacao a viscosidade da clara de ovos produzidos por poedeiras de duas diferentes linhagens (Carijo Barbada eIsa Brown ), as quais receberam dietas contendo urucum (1,5 e 2,0%) ou aditivo sintetico. Foram realizadas as analises de umidade, altura do albumen, pH, viscosidade, formacao e estabilidade da espuma. A linhagem Carijo Barbada apresentou menor quantidade de albumen, menor umidade e maior viscosidade que a linhagem Isa Brown, entretanto, com a estocagem, a viscosidade diminuiu significativamente para ambas as linhagens. Inicialmente, a adicao de 2,0% de urucum ou aditivo sintetico foi suficiente para aumentar a viscosidade em ovos obtidos de ambas as linhagens, mas com a estocagem, somente o controle manteve maior viscosidade. A baixa viscosidade nao interferiu na densidade e estabilidade da espuma.

Genetic parameters for growth characteristics of free-range chickens under univariate random regression models

Repeated measures from the same individual have been analyzed by using repeatability and finite dimension models under univariate or multivariate analyses. However, in the last decade, the use of random regression models for genetic studies with longitudinal data have become more common. Thus, the aim of this research was to estimate genetic parameters for body weight of four experimental chicken lines by using univariate random regression models. Body weight data from hatching to 84 days of age (n = 34,730) from four experimental free-range chicken lines (7P, Caipirão da ESALQ, Caipirinha da ESALQ and Carijó Barbado) were used. The analysis model included the fixed effects of contemporary group (gender and rearing system), fixed regression coefficients for age at measurement, and random regression coefficients for permanent environmental effects and additive genetic effects. Heterogeneous variances for residual effects were considered, and one residual variance was assigned for each of six subclasses of age at measurement. Random regression curves were modeled by using Legendre polynomials of the second and third orders, with the best model chosen based on the Akaike Information Criterion, Bayesian Information Criterion, and restricted maximum likelihood. Multivariate analyses under the same animal mixed model were also performed for the validation of the random regression models. The Legendre polynomials of second order were better for describing the growth curves of the lines studied. Moderate to high heritabilities (h(2) = 0.15 to 0.98) were estimated for body weight between one and 84 days of age, suggesting that selection for body weight at all ages can be used as a selection criteria. Genetic correlations among body weight records obtained through multivariate analyses ranged from 0.18 to 0.96, 0.12 to 0.89, 0.06 to 0.96, and 0.28 to 0.96 in 7P, Caipirão da ESALQ, Caipirinha da ESALQ, and Carijó Barbado chicken lines, respectively. Results indicate that genetic gain for body weight can be achieved by selection. Also, selection for body weight at 42 days of age can be maintained as a selection criterion.

Avaliação do desempenho zootécnico de genótipos de frangos de corte utilizando-se a análise de medidas repetidas

Objetivou-se avaliar genotipos de frangos de corte por meio do desempenho zootecnico utilizando-se medidas repetidas. Os tratamentos consistiram de quatro genotipos (A, B, C e D) e dois sexos avaliados em seis idades (7, 14, 21, 28, 35 e 42 dias). As variaveis analisadas foram: consumo medio de alimento (CONS), peso vivo medio (PV) e conversao alimentar (CA). O delineamento experimental foi em blocos incompletos desbalanceados, em esquema fatorial 4x2 nas parcelas experimentais, com seis medidas realizadas no decorrer do experimento. A analise estatistica foi realizada por meio do procedimento MIXED do SAS®, sendo testadas cinco estruturas de variância e covariância do erro. As medias foram estimadas por quadrados minimos e comparadas pelo teste Tukey-Kramer. Foram estimadas funcoes de resposta quadratica para CONS e CA e Gompertz para PV e seus respectivos coeficientes de determinacao, pelo procedimento NLIN do SAS®. Detectaram-se efeitos de algumas interacoes triplas ou duplas para todas as variaveis. Verificaram-se diferencas significativas entre genotipos dentro de cada idade e sexo para CONS e PV e para CA entre genotipos e sexos, dentro de cada idade, apenas aos 42 e a partir dos 21 dias, respectivamente. Constatou-se que o genotipo D, apesar de apresentar maiores medias de CONS e PV, nao mostrou menor CA, que foi verificada nos genotipos C e B. As funcoes de resposta estimadas explicaram adequadamente cada variavel em funcao da idade, constatando-se que o CONS e PV dos machos do genotipo D foram maiores a partir dos 14 dias e dos 28 aos 42 dias, distinguindo este tratamento dos demais. A melhor CA foi verificada nos machos e no genotipo C. E possivel avaliar o desempenho zootecnico de frangos de corte por medidas repetidas, sendo que os genotipos B e C apresentaram melhor desempenho zootecnico.