Seasonal variation of Alphitobius diaperinus population in broiler facilities in the center-north region of the state of São Paulo

The seasonality of Alphitobius diaperinus population was studied during different seasons during one year, in broiler facilities located in the center-north region of the State of São Paulo. Parasite counting was weekly carried out by the use of traps adapted from the modified model of Arends. During the experimental period, facilities were not submitted to chemical treatment, and the litter was changed between flocks. A lower number of adults and larvae was observed during autumn, with the peak registered in the summer. There was no significant difference between spring and winter averages (adults and larvae), and between spring and summer averages (adults). Average temperatures in the facilities varied from 23.4ºC (winter) to 27.1ºC (spring). The environmentally controlled systems used by the broiler industry provide an adequate habitat for A. diaperinus development. The continuous monitoring of the population of this parasite is essential for designing control strategies, and this can be accomplished by utilizing the traps used in the present experiment.

SEROLOGICAL RESPONSE OF CHICKENS TO INFECTION WITH SALMONELLA-GALLINARUM S-PULLORUM DETECTED BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY

The serological response to Salmonella pullorum and S. gallinarum infection in chickens was studied with an indirect enzyme-linked immunosorbent assay (ELISA). In broiler chickens, a more virulent strain of S. pullorum produced a significantly lower serum IgG titer than did a less virulent strain. In laying hens, the serum and egg-yolk IgG titers were very similar. In chickens infected with S. gallinarum, high IgG titers persisted for 30 weeks. In chickens reinfected with this strain, each reinfection was followed by transitory increases in IgG lasting no longer than 2 weeks. Serum samples from Brazil taken from a laying flock with evidence of fowl typhoid showed much higher antibody levels than did those from three uninfected flocks. Using lipopolysaccharide as the detecting antigen, infections caused by these salmonellae could be differentiated from those caused by other groups. Incorporation of the appropriate flagella antigen in the ELISA allowed differentiation between infections caused by S. pullorum and S. enteritidis.

Predicting body and carcass characteristics of 2 broiler chicken strains using support vector regression and neural network models

As a new modeling method, support vector regression (SVR) has been regarded as the state-of-the-art technique for regression and approximation. In this study, the SVR models had been introduced and developed to predict body and carcass-related characteristics of 2 strains of broiler chicken. To evaluate the prediction ability of SVR models, we compared their performance with that of neural network (NN) models. Evaluation of the prediction accuracy of models was based on the R-2, MS error, and bias. The variables of interest as model output were BW, empty BW, carcass, breast, drumstick, thigh, and wing weight in 2 strains of Ross and Cobb chickens based on intake dietary nutrients, including ME (kcal/bird per week), CP, TSAA, and Lys, all as grams per bird per week. A data set composed of 64 measurements taken from each strain were used for this analysis, where 44 data lines were used for model training, whereas the remaining 20 lines were used to test the created models. The results of this study revealed that it is possible to satisfactorily estimate the BW and carcass parts of the broiler chickens via their dietary nutrient intake. Through statistical criteria used to evaluate the performance of the SVR and NN models, the overall results demonstrate that the discussed models can be effective for accurate prediction of the body and carcass-related characteristics investigated here. However, the SVR method achieved better accuracy and generalization than the NN method. This indicates that the new data mining technique (SVR model) can be used as an alternative modeling tool for NN models. However, further reevaluation of this algorithm in the future is suggested.

Poultry offal meal in broiler chicken feed

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Light emitting diode (LED) use in artificial lighting for broiler chicken production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunomodulatory activity and control of Salmonella Enteritidis colonization in the intestinal tract of chickens by Lactobacillus based probiotic

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Assessment of broiler surface temperature variation when exposed to different air temperatures

This study was conducted to determine the effect of the air temperature variation on the mean surface temperature (MST) of 7-to 35-day-old broiler chickens using infrared thermometry to estimate MST, and to study surface temperature variation of the wings, head, legs, back and comb as affected by air temperature and broiler age. One hundred Cobb(R) broilers were used in the experiment. Starting on day 7, 10 birds were weekly selected at random, housed in an environmental chamber and reared under three distinct temperatures (18, 25 and 32 degrees C) to record their thermal profile using an infrared thermal camera. The recorded images were processed to estimate MST by selecting the whole area of the bird within the picture and comparing it with the values obtained using selected equations in literature, and to record the surface temperatures of the body parts. The MST estimated by infrared images were not statistically different (p > 0.05) from the values obtained by the equations. MST values significantly increased (p < 0.05) when the air temperature increased, but were not affected by bird age. However, age influenced the difference between MST and air temperature, which was highest on day 14. The technique of infrared thermal image analysis was useful to estimate the mean surface temperature of broiler chickens.

Efeito do uso de probiótico sobre o desempenho e atividade de enzimas digestivas de frangos de corte

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da restrição alimentar protéica ou energética sobre o crescimento de frangos de corte criados em diferentes temperaturas ambiente

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito da cloração da água de beber e do nível energético da ração sobre o ganho de peso e consumo de água em frangos de corte

Dois experimentos foram realizados com o objetivo de pesquisar o efeito da adição de cloro à água de beber e dos diferentes níveis de energia na ração sobre o ganho de peso e consumo de água em frangos de corte. No experimento 1, as aves foram alimentadas com dois níveis de energia metabolizável na ração (2900 e 3200 kcal EM/kg) em cada fase da criação. Foi observado que o nível energético não influi no consumo de água e no ganho de peso dos frangos de corte. No experimento 2, o nível de energia metabolizável da ração foi de 3200 kcal EM/kg e a água de beber foi clorada com hipoclorito de sódio a 11%, correspondendo a 5 ppm de cloro. O consumo de água foi menor nas aves que receberam água clorada. Apesar de o consumo de água ter sido menor, não houve redução no ganho de peso das aves que receberam hipoclorito de sódio. A adição de cloro à água de beber melhorou os índices bacteriológicos. Os resultados obtidos nestes experimentos evidenciam que os níveis energéticos das rações testadas não influenciaram o consumo de água dos frangos de corte; entretanto, a adição de cloro reduziu a ingestão de água, porém sem influir no ganho de peso nas aves tratadas.

Ingredient classification according to the digestible amino acid profile: an exploratory analysis

This study aimed: 1) to classify ingredients according to the digestible amino acid (AA) profile; 2) to determine ingredients with AA profile closer to the ideal for broiler chickens; and 3) to compare digestible AA profiles from simulated diets with the ideal protein profile. The digestible AA levels of 30 ingredients were compiled from the literature and presented as percentages of lysine according to the ideal protein concept. Cluster and principal component analyses (exploratory analyses) were used to compose and describe groups of ingredients according to AA profiles. Four ingredient groups were identified by cluster analysis, and the classification of the ingredients within each of these groups was obtained from a principal component analysis, showing 11 classes of ingredients with similar digestible AA profiles. The ingredients with AA profiles closer to the ideal protein were meat and bone meal 45, fish meal 60 and wheat germ meal, all of them constituting Class 1; the ingredients from the other classes gradually diverged from the ideal protein. Soybean meal, which is the main protein source for poultry, showed good AA balance since it was included in Class 3. on the contrary, corn, which is the main energy source in poultry diets, was classified in Class 8. Dietary AA profiles were improved when corn and/or soybean meal were partially or totally replaced in the simulations by ingredients with better AA balance.

Efeito do isolamento térmico de telhado sobre o desempenho de frangos de corte alojados em diferentes densidades

O objetivo deste trabalho foi avaliar o efeito do uso de isolante térmico de telhado instalado como forro sob a cobertura no desempenho de frangos alojados em diferentes densidades (10, 16 e 22 aves/m²) e nas características da cama de aviário em galpão convencional. O experimento foi realizado durante o verão, utilizando 3328 aves da linhagem Hubbard, distribuídas em um delineamento inteiramente casualizado, em um esquema fatorial 3x2 (densidade e sexo), com quatro repetições dentro de cada ambiente. Para a comparação dos ambientes, utilizou-se a análise conjunta. Durante o período experimental, registraram-se dados de temperatura ambiente em vários pontos do galpão e em diversos horários, umidade relativa e carga térmica radiante. O teor de nitrogênio e matéria seca e a temperatura da cama foram determinados. No ambiente com isolante térmico, as temperaturas ambientais médias e a amplitude térmica diária foram menores e a umidade relativa do ar, maior. O desempenho das aves foi melhor no ambiente com isolante térmico, no qual as aves tiveram maior consumo de ração, maior ganho de peso, melhor conversão alimentar, menor mortalidade e maior produção por área. A temperatura retal das aves do ambiente sem isolante térmico foi mais elevada. À medida que se elevou a densidade, a mortalidade aumentou, porém a produção por área foi maior. O uso do isolante não influenciou a produção de cama, mas diminuiu a porcentagem de nitrogênio na cama. Com o aumento da densidade, a produção de cama elevou-se, pelo maior volume de excretas, mas não influenciou sua porcentagem de nitrogênio. O uso do isolante térmico permitiu aumento da densidade de criação dos frangos.

Aspectos Microbiológicos e Demanda de Cloro de Amostras de Água de Dessedentação de Frangos de Corte Coletadas em Bebedouros Pendulares

Foram analisadas 72 amostras da água de dessedentação de frangos de corte, 18 da entrada e 54 dos bebedouros pendulares. As amostras foram submetidas às mensurações de coliformes totais, coliformes fecais, estreptococos fecais, Escherichia coli e organismos mesófilos, além da detecção da presença de Salmonella sp e da taxa de demanda de cloro. Os resultados evidenciaram uma elevada contaminação bacteriológica, já na primeira semana, com os indicadores na ordem de 10³ a 10(5). Não houve isolamento de nenhuma cepa de Salmonella sp, provavelmente por não haver ave infectada no plantel. A taxa de demanda de cloro mostrou-se elevada, devido ao maior acúmulo de matéria orgânica nos bebedouros, com o ápice na quinta semana (98,7%), seguida de uma leve diminuição na sexta semana (98,5%). As análises dos resultados evidenciam o bebedouro pendular como um instrumento depreciativo e ineficiente em relação às qualidades higiênico-sanitárias das águas fornecidas aos frangos de corte, contribuindo para um alto risco de contaminação por patógenos de veiculação hídrica. Preconizam-se a utilização de modelos de bebedouros menos deletérios e o monitoramento semanal de cloro residual nos bebedouros pendulares, a fim de se obter uma desinfecção satisfatória da água.

A survey for maintenance of virulent newcastle disease virus-free area in poultry production in Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hepatic concentration of heat shock protein 70 kD (Hsp70) in broilers subjected to different thermal treatments

1. The relationship between repeated thermal treatments and hepatic synthesis of Hsp 70 was studied in broiler chickens.2. Sixty broilers were submitted to 5 different treatments (12 birds each) from day 1 to day 42. Four groups were kept in a thermoneutral environment and subjected to 0, 1, 2 and 3 heat stress episodes at 35 degrees C for 4 h per week (TN-0, TN-1, TN-2 and TN-3, respectively). The last group (HT-35) was reared at a room temperature of 35 degrees C.3. From 39 to 42 old, the birds experienced acute heat stress at 41 degrees C. Resistance to heat stress was evaluated by the time taken for rectal temperature to increase by 3 degrees C above the pre-treatment value. Livers were collected (before and after heat stress) and Hsp70 was determined using Western Blot analysis with monoclonal anti-Hsp70 antibody.4. Resistance to heat stress and concentration of Hsp70 were higher in those birds subjected to more heat stress episodes during the experimental period (TN-3) and HT-35. A positive correlation was observed between Hsp70 concentration and the time taken for a 3 degrees C increase in rectal temperature (r=0.42; P<0.01).5. Exposing birds to episodes of heat stress (35 degrees C) during rearing may improve their resistance to acute heat stress, but the previous thermal history did not seem to influence the hepatocyte Hsp70 content after exposure to more severe heat stress (41 degrees C).