Breeder age and bone development in broiler chicken embryos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phytogenic additives and organic acids in broiler chicken diets

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

Effect of broiler chicken age on ileal digestibility of corn germ meal

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Histopathological and ultrastructural characteristics of myeloid leukosis in broiler chicken

Caracterizaram-se a linhagem e o grau de diferenciação das células neoplásicas no estudo histopatológico e ultraestrutural da leucose mielóide. Histologicamente as células neoplásicas apresentaram pleomorfismo, núcleos ovais, nucléolos proeminentes, cromatina distribuída de maneira irregular, figuras de mitose atípicas e moderada quantidade de citoplasma contendo granulações eosinofílicas esféricas. Essas características indicam a linhagem mielóide. Ultraestruturalmente evidenciaram-se células com núcleo oval, volumoso, eletrodenso, com predomínio de eucromatina e citoplasma com numerosos grânulos esféricos, eletrodensos e homogêneos, indicando mielócitos com diferenciação para eosinófilos. Constatou-se também a presença de partículas virais tipo-C no espaço intercelular dos túbulos renais, no interior de vesículas intracitoplasmáticas dos mielócitos imaturos presentes na medula óssea e ovário, e PCR positivo para ALV-J.

Assessing locomotion deficiency in broiler chicken

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

DETECTION OF SALMONELLA-TYPHIMURIUM IN A BROILER CHICKEN FLOCK

An outbreak of Salmonella typhimurium in a commercial broiler chicken flock is reported. The signs of the disease started on the 5th day-old. The symptoms, the gross alterations and the damage to the birds and to the farm are discussed.

Dietary vitamin or mineral mix removal during the finisher period on broiler chicken performance

The effect of dietary vitamin (VS) and mineral (MS) mix withdrawal between 42 and 49 d of age on broiler chicken performance was evaluated. The diets were formulated based on corn and soybean meal, and the experiments were conducted in floor pens using wood shavings as litter. Trial I evaluated withdrawal of VS and MS mix at 42, 45, and 49 d. The results of this trial showed that VS and MS mix withdrawal at 42 d of age did not impair feed intake (FI) or weight gain (WG), but feed conversion (FC) was improved (P = 0.043) when both mixes were maintained in the diets until 49 d of age. Trial 2 assessed the withdrawal of VS or MS mix at 42 d of age. FI and WG were not affected by withdrawal, but FC was poorer (P = 0.035) for the broilers fed the diet without VS. The relative liver weight was reduced by VS or MS mix withdrawal (P = 0.014 and P = 0.001, respectively). Carcass, breast, and leg yields were not affected by VS or MS mix withdrawals in either trial. The findings of the study suggested that VS mix withdrawal during the final period of broiler chicken growth was more deleterious than the withdrawal of MS mix, because it affected FC ratio. VS or MS withdrawal during this period did not affect carcass yield.

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.

A description of the growth of the major body components of 2 broiler chicken strains

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

Influence of dietary protein level on the broiler chicken's response to methionine and betaine supplements

Two experiments were conducted to compare broiler chicken responses to methionine and betaine supplements when fed diets with low protein and relatively high metabolizable energy levels (17%, 3.3 kcal/g) or moderate protein and lower metabolizable energy levels (24%, 3.0 kcal/g), resulting in different levels of carcass fat. In Experiment 1, the basal diets were formulated with corn, soybean meal, poultry by-product meal, and poultry oil. In Experiment 2, glucose monohydrate was also added, so that identical amino acid profiles could be maintained in the 17 and 24% protein diets. On average, feeding the 17 vs. 24% protein diet decreased 21-d body weight gain by 20%, increased feed conversion ratio (FCR) by 13%, and increased abdominal fat pad weight by 104%. Methionine and betaine supplements improved the performance of chicks fed the 24% protein diet in both experiments, as indicated by body weight gain and FCR. Only supplementary methionine increased performance of chicks fed 17% protein diets, and then only in Experiment 2. Neither methionine nor betaine decreased abdominal fat pad size in either experiment. Methionine supplementation decreased relative liver size and increased breast muscle protein. Both methionine and betaine increased sample feather weight, but when expressed as a percentage of body weight, no significant differences were detected. It is concluded that increasing carcass fat by manipulating percentage dietary protein level or amino acid balance does not influence betaine's activity as a lipotropic agent.

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)

Extrinsic factors affecting water absorption in chilling of broiler chicken carcasses

Brazil occupies an outstanding position as a producer and exporter of chicken meat, and the maintenance and expansion of this position require a constant evolution, especially in variables which determine quality. An important quality parameter of poultry meat is the amount of water absorbed by the carcass during processing. In Brazil, carcasses chilling is done by immersion in chilled water. In this process, the carcass is rehydrated and the water lost during transport and initial operations is replaced. At this stage, some care is needed to prevent the absorption of water upper than the level allowed by Brazilian law. This project aimed to evaluate extrinsic factors that can influence the absorption of water by the chicken meat. For this, 144 Cobb chickens divided into 24 groups of six birds were used. At 42 days of age, one chicken of each group, with weight ranging up to 10% more or less from the average of the group, was slaughtered in an experimental pilot scale abattoir where slaughter procedures were conducted under strictly controlled conditions. The chilling procedure was performed following a completely randomized design with factorial arrangement 3x2, where the factors were: three temperatures in the first section of the chilling system (4, 10 and 16ºC) and two degrees of water hardness (hard and soft water), with six treatments and four replications. Brazilian law provides that the water temperature in the first section of the chiller must not be higher than 16ºC, and the length of the carcasses in this section shall not exceed 30 minutes. All carcasses remained in the first section of the chiller for 30 minutes and then were transferred to another tank with water at 4ºC, remaining there until reaching 7ºC. The carcasses were weighed before and after chilling, to evaluate the percentage of water absorbed. The water absorption was influenced by the initial temperature of the water in the chiller and by the water hardness. When initially immersed in water at 4ºC, carcasses water absorption averaged 2.70%, a significantly lower absorption than the values found for the carcasses that were initially immersed in water at 16ºC, 3.83% (p<0.05). The carcasses immersed in water at 10ºC had mean water absorption of 3.66%, not differing from the means observed in the other two treatments (p>0.05). In hard water, the average water absorption was 2.46% and, in soft water, 4.33% (p<0.05). In all treatments, the water absorption did not exceed the limit established by Brazilian legislation, which is a maximum of 8%. This information is important to control the absorption of water by carcasses in chicken meat processing, preventing consumers from being harmed.

Air velocity and exposure time to ventilation affect body surface and rectal temperature of broiler chickens

Increasing air movement over poultry by using fans (ventilation) has become an accepted means of reducing environmental heat stress over the last several years. The purpose of this study was to evaluate the effect of air velocity and exposure time to ventilation on body surface and rectal temperature of broiler chickens. Male broiler chickens aged 36-42 days were placed in individual wire cages and exposed to five different air velocities (5.7, 4.2, 3.1, 2.4, or 1.8 m/sec). Throughout the experiment head, back, leg, and rectal temperatures were monitored every 10 min during a 30-min period for each air velocity. The data showed that exposure time to the wind affected (P<.05) leg and body temperature, with a rapid reduction being observed during the first 10 min. There was a reduction in leg temperature with air velocity of 2 m/sec; however, air velocity lower than 4.5 m/sec was not effective in decreasing head and back temperature. The results suggest that air velocity of 2 m/sec, in air temperature of 29 degrees C, improves heat loss in the birds. The data also indicate that exposure time to ventilation seems to be a critical point in the maintenance of bird thermal homeostasis.