999 resultados para Poultry quality
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The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.
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Bovine meat and bone meal (MBM) was widely used in animal diets until outbreaks of Bovine Spongiform Encefalopathy (BSE) occurred in some countries. It has not been confirmed yet whether or not BSE may be transmitted to man through chicken meat originated from poultry that had been fed diets containing MBM. Therefore, consumers nowadays express preference for meat originated from birds fed exclusively vegetable diets. This study analyzed samples of major breast muscle (Pectoralis major) using mass spectrometry of stable isotopes (carbon and nitrogen) as a means to assess the presence of MBM in broiler diets, a technique that might be used in the certification of poultry quality. A total of 150 day-old chicks were reared in five randomized treatments with increasing MBM dietary inclusion levels (0, 1, 2, 4 and 8%). on day 42, breast muscle samples were collected from three birds per treatment and used in the determination of 13C/12C and 15N/14N isotope ratios. The breast muscle isotope values were expressed as delta in parts per thousand (delta ). The following carbon isotope values (13C) were found: 18.74 ±0.11, 18.51 ±0.19, 18.24 ±0.10, -17.79 ±0.12, and -17.15 ±0.15 for 0, 1, 2, 4 and 8% MBM dietary levels, respectively. Nitrogen isotope values (15N) were 1.65 ±0.14, 1.65 ±0.28, 1.72 ±0.08, 1.95 ±0.16, and 2.52 ± 0.09 for 0, 1, 2, 4 and 8% MBM dietary levels, respectively. This study showed important differences in delta13C and delta15N values in breast meat, evidencing a simultaneous enrichment of this isotopic pair, which allowed tracing MBM in bird diets. Analysis of carbon and nitrogen stable isotopes may be used to ensure feeding with exclusively vegetable diets, and might also be used as a reliable evaluation tool in broiler meat certification. The diet with 1% inclusion level of MBM and the exclusively vegetable diet showed similar results.
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The present study evaluated the effect of the use of natural antioxidants in different spent hens processed meat, the physical-chemical and sensory characteristics of product were analyzed. The experiment was conducted at the Technology Laboratory of Animal Products, Department of Technology - FCAV/Unesp - Campus of Jaboticabal. Forty-five laying hens with approximately 80 weeks of age were used, distributed in a completely randomized experimental design in a 4x4 factorial arrangement, 4 condiment types (control, rosemary, clove and oregano, and the last three natural antioxidants) and 4 storage times (0; 3; 6 and 9 days at 4°C), with sixteen treatments and tree repetitions. It were evaluated the characteristics of humidity, pH, color, cooking loss, shear force, TBARS number and sensory analyze. The averages were obtained by Tukey test 5% of significance. The results showed an interaction between the storage time and condiments types in all analyzed parameters. It was concluded that oregano use decreased the processed meat oxidation, also pleased the judges in sensory analysis. The lowest notes in sensory analysis were obtained with the treatment that contained clove.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Vitamin E supplementation, cereal feed type and consumer sensory perceptions of poultry meat quality
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Lipid oxidation leads to meat spoilage and has been reported to cause adverse changes in the flavour and texture of poultry meat. Vitamin E has been found to be effective in delaying lipid oxidation. The aim of this study was to determine whether the vitamin E supplementation of chicken feed influences the consumers' perception of the quality of chicken meat under normal display and storage conditions. Untrained consumers (n 32) evaluated cooked breast meat from chickens (both corn fed and wheat fed) supplemented with 75 250 or 500 mg/kg vitamin E and after storage at 4° C for 4 and 7 d. Factorial analysis found an interaction between vitamin E treatment and storage day upon the perceived juiciness (P = 0.023) and tenderness (P = 0.041) of the chicken meat. Perceptions of quality relative to vitamin E level were more evident on day 4 than day 7. When the two cereal types were compared, the time-related subgroup effects were observed only in meat from corn-fed chickens supplemented with either 75 or 250 mg/kg, which was perceived to be juicier (P = 0.018) and more tender (P = 0.020) than that supplemented at the 500 mg/kg level. These results imply that the two lower concentrations of vitamin E have some advantages over 500 mg/kg, but for optimal consumer acceptance of corn-fed chicken meat, we suggest that 250 mg/kg vitamin E should be added to corn-fed poultry feed. There was no evidence to suggest any advantages in changing the current amount of vitamin E (75 mg/kg) used to rear wheat-fed birds.
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This paper compares the development of the poultry industry in Italy with the UK. Earlier research has suggested that the UK poultry industry developed a symbiotic relationship with the emerging supermarket retailers. Italy had a retarded supermarket sector. Its distribution system favoured small-scale, independent butchers rather than chains of self-service supermarkets. Despite this the Italian poultry industry also modernised, adopting US technologies. The catalyst for this modernisation was technological innovation in refrigeration technologies that enabled Italian consumers and independent retailers to be persuaded of the merits of the new ‘technological’ chicken. While the Italian market has become dominated by AIA and Amadori in recent years, the key innovators were the entrepreneurs that created the company called Arena.
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The effect of a commercial organic acid (OA) product on BW loss (BWL) during feed withdrawal and transportation, carcass yield, and meat quality was evaluated in broiler chickens. Two experiments were conducted in Brazil. Commercial houses were paired as control groups receiving regular water and treated groups receiving OA in the water. Treated birds had a reduction in BWL of 37 g in experiment 1 and 32.2 g in experiment 2. In experiment 2, no differences were observed in carcass yield between groups. Estimation of the cost benefit suggested a 1: 16 ratio by using the OA. In experiment 3, conducted in Mexico, significant differences on water consumption, BWL, and meat quality characteristics were observed in chickens that were treated with the OA (P < 0.05). These data suggest this OA product may improve animal welfare and economic concerns in the poultry industry by reducing BWL and improving meat quality attributes.
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The PhD project was focused on the study of the poultry welfare conditions and improvements. The project work was divided into 3 main research activities. A) Field evaluation of chicken meat rearing conditions kept in intensive farms. Considering the lack of published reports concerning the overall Italian rearing conditions of broiler chickens, a survey was carried out to assess the welfare conditions of broiler reared in the most important poultry companies in Italy to verify if they are in accordance with the advices given in the European proposal COM (2005) 221 final. Chicken farm conditions, carcass lesions and meat quality were investigated. 1. The densities currently used in Italy are in accordance with the European proposal COM 221 final (2005) which suggests to keep broilers at a density lower than 30-32 kg live weight/m2 and to not exceed 38-40 kg live weight/m2. 2. The mortality rates in summer and winter agree with the mortality score calculated following the formula reported in the EU Proposal COM 221 final (2005). 3. The incidence of damaged carcasses was very low and did not seem related to the stocking density. 4. The FPD scores were generally above the maximum limit advised by the EU proposal COM 221 final (2005), although the stocking densities were lower than 30-32 kg live weight per m2. 5. It can be stated that the control of the environmental conditions, particularly litter quality, appears a key issue to control the onset of foot dermatitis. B) Manipulation of several farm parameters, such litter material and depth, stocking density and light regimen to improve the chicken welfare conditions, in winter season. 1. Even though 2 different stocking densities were established in this study, the performances achieved from the chickens were almost identical among groups. 2. The FCR was significantly better in Standard conditions contrarily to birds reared in Welfare conditions with lower stocking density, more litter material and with a light program of 16 hours light and 8 hours dark. 3. In our trial, in Standard groups we observed a higher content of moisture, nitrogen and ammonia released from the litter. Therefore it can be assumed that the environmental characteristics have been positively changed by the improvements of the rearing conditions adopted for Welfare groups. 4. In Welfare groups the exhausted litters of the pens were dryer and broilers showed a lower occurrence of FPD. 5. The prevalence of hock burn lesions, like FPD, is high with poor litter quality conditions. 6. The combined effect of a lower stocking density, a greater amount of litter material and a photoperiod similar to the natural one, have positively influenced the chickens welfare status, as a matter of fact the occurrence of FPD in Welfare groups was the lowest keeping the score under the European threshold of the proposal COM 221 final(2005). C) The purpose of the third research was to study the effect of high or low stocking density of broiler chickens, different types of litter and the adoption of short or long lighting regimen on broiler welfare through the evaluation of their productivity and incidence of foot pad dermatitis during the hot season. 1. The feed efficiency was better for the Low Density than for High Density broilers. 2. The appearance of FPD was not influenced by stocking density. 3. The foot examination revealed that the lesions occurred more in birds maintained on chopped wheat straw than on wood shaving. 4. In conclusion, the adoptions of a short light regimen similar to that occurring in nature during summer reduces the feed intake without modify the growth rate thus improving the feed efficiency. Foot pad lesion were not affected neither by stocking densities nor by light regimens whereas wood shavings exerted a favourable effect in preserving foot pad in good condition. D) A study was carried out to investigate more widely the possible role of 25-hydroxycholecalciferol supplemented in the diet of a laying hen commercial strain (Lohmann brown) in comparison of diets supplemented with D3 or with D3 + 25- hydroxycholecalciferol. Egg traits during a productive cycle as well as the bone characteristics of the layers have been as well evaluated to determine if there the vitamin D3 may enhance the welfare status of the birds. 1. The weight of the egg and of its components is often greater in hens fed a diet enriched with 25-hydroxycholecalciferol. 2. Since eggs of treated groups are heavier and a larger amount of shell is needed, a direct effect on shell strength is observed. 3. At 30 and at 50 wk of age hens fed 25 hydroxycholecalciferol exhibited greater values of bone breaking force. 4. Radiographic density values obtained in the trial are always higher in hens fed with 25-hydroxycholecalciferol of both treatments: supplemented for the whole laying cycle (25D3) or from 40 weeks of age onward (D3+25D3).
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The purpose of the PhD research was the identification of new strategies of farming and processing, with the aim to improve the nutritional and technological characteristics of poultry meat. Part of the PhD research was focused on evaluation of alternative farming systems, with the aim to increase animal welfare and to improve the meat quality and sensorial characteristics in broiler chickens. It was also assessed the use of innovative ingredients for marination of poultry meat (sodium bicarbonate and natural antioxidants) The research was developed by studying the following aspects: - Meat quality characteristics, oxidative stability and sensorial traits of chicken meat obtained from two different farming systems: free range vs conventional; - Meat quality traits of frozen chicken breast pre-salted using increasing concentrations of sodium chloride; - Use of sodium bicarbonate in comparison with sodium trypolyphosphate for marination of broiler breast meat and phase; - Marination with thyme and orange essential oils mixture to improve chicken meat quality traits, susceptibility to lipid oxidation and sensory traits. The following meat quality traits analyseswere performed: Colour, pH, water holding capacity by conventional (gravimetric methods, pressure application, centrifugation and cooking) and innovative methods (low-field NMR and DSC analysis) ability to absorb marinade soloutions, texture (shear force using different probes and texture profile analysis), proximate analysis (moisture, proteins, lipids, ash content, collagen, fatty acid), susceptibility to lipid oxidation (determinations of reactive substances with thiobarbituric acid and peroxide value), sensorial analysis (triangle test and consumer test).
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Recently, global meat market is facing several dramatic changes due to shifting in diet and life style, consumer demands, and economical considerations. Firstly, there was a tremendous increase in the poultry meat demand. Furthermore, current forecast and projection studies pointed out that the expansion of the poultry market will continue in future. In response to this demand, there was a great success to increase growth rate of meat-type chickens in the last few decades in order to optimize the production of poultry meat. Accordingly, the increase of growth rate induced the appearance of several muscle abnormalities such as pale-soft-exudative (PSE) syndrome and deep-pectoral-myopathy (DPM) and more recently white striping and wooden breast. Currently, there is growing interest in meat industry to understand how much the magnitude of the effect of these abnormalities on different quality traits for raw and processed meat. Therefore, the major part of the research activities during the PhD project was dedicated to evaluate the different implications of recent muscle abnormalities such as white striping and wooden breast on meat quality traits and their incidence under commercial conditions. Generally, our results showed that the incidence of these muscle abnormalities was very high under commercial conditions and had great adverse impact on meat quality traits. Secondly, there is growing market share of convenient, healthy, and functional processed meat products. Accordingly, the remaining part of research activities of the PhD project was dedicated to evaluate the possibility to formulate processed meat products with higher perceived healthy profile such as phosphate free-marinated chicken meat and low sodium-marinated rabbit meat products. Overall all findings showed that sodium bicarbonate can be considered as promising component to replace phosphates in meat products, while potassium chloride under certain conditions was successfully used to produce low marinated rabbit meat products.
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The goals of this research were to estimate the phenotypic correlations among various meat quality traits from a male broiler line and to describe the relation among these variables. Phenotypical correlations were determined among quality traits, isolating the effects of slaughter date, the age of the mother and sex. The evaluated traits were pH measurements taken at time 0 and at 6 and 24 hours after slaughtering, color parameters, water loss due to exudation, thawing and cooking of the meat, and shear force. Important associations (P<0.01) were found to be significant and, in most cases, weak or moderate, varying from -0.35 to 0.28. The initial pH of the meat was not associated (P>0.05) to the other traits of the meat, whereas the pH at 24 hours after slaughter was able of directly interfering with the attributes of the meat, since this trait was inversely related with lightness and water losses, which indicates an effect of pH fall along 24h after slaughtering on protein denaturation. This study demonstrates that the variables of poultry meat quality are related and that there is a phenotypical association between lightness and cooking losses and the other attributes of the meat. The pH at 24 hours after slaughtering, lightness and cooking losses could be efficient meat quality indicators in this broiler line.
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Aflatoxin B1 (AFB1) has been recognized to produce cancer in human liver. In addition, epidemiological and laboratory studies demonstrated that the respiratory system was a target for AFB1. Exposure occurs predominantly through the food chain, but inhalation represents an additional route of exposure. The present study aimed to examine AFB1 exposure among poultry workers in Portugal. Blood samples were collected from a total of 31 poultry workers from six poultry farms. In addition, a control group (n = 30) was included comprised of workers who undertook administrative tasks. Measurement of AFB1 in serum was performed by enzyme-linked immunosorbent assay (ELISA). For examining fungi contamination, air samples were collected through an impaction method. Air sampling was obtained in pavilion interior and outside the premises, since this was the place regarded as the reference location. Using molecular methods, toxicogenic strains (aflatoxin-producing) were investigated within the group of species belonging to Aspergillus flavus complex. Eighteen poultry workers (59%) had detectable levels of AFB1 with values ranging from <1 ng/ml to4.23 ng/ml and with a mean value of 2 ± 0.98ng/ml. AFB1 was not detected in the serum sampled from any of the controls. Aspergillus flavus was the fungal species third most frequently found in the indoor air samples analyzed (7.2%) and was the most frequently isolated species in air samples containing only Aspergillus genus (74.5%). The presence of aflatoxigenic strains was only confirmed in outdoor air samples from one of the units, indicating the presence of a source inside the building in at least one case. Data indicate that AFB1 inhalation represents an additional risk in this occupational setting that needs to be recognized, assessed, and prevented.