Preslaughter mortality of broilers in relation to lairage and season in a subtropical climate

The preslaughter handling and transport of broilers are stressful operations that might affect welfare and meat quality and could increase numbers of deaths before slaughter. However, the influence of thermal factors during transportation and lairage at slaughterhouses is complex in subtropical regions, where increasing temperature and high RH are the major concerns regarding animal survival before slaughter. In this study we assessed the influence of a controlled lairage environment on preslaughter mortality rates of broiler chickens that were transported during different seasons of the year and had varying lairage times in the subtropical climate. Preslaughter data from 13,937 broiler flocks were recorded daily during 2006 in a commercial slaughterhouse in southeastern Brazil. The main factors that influenced daily mortality rate were mean dry bulb temperature and RH, lairage time, daily periods, density of broilers per crate, season of the year, stocking density per lorry, transport time, and distance between farms and slaughterhouse. A holding area at the slaughterhouse with environmental control was assessed. Using a double GLM for mean and dispersion modeling, the seasons were found to have significant effects (P < 0.05) on average mortality rates. The highest incidence was observed in summer (0.42%), followed by spring (0.39%), winter (0.28%), and autumn (0.23%). A decrease of preslaughter mortality of broilers during summer (P < 0.05) was observed when the lairage time was increased, mainly after 1 h of exposure to a controlled environment. Thus, lairage for 3 to 4 h in a controlled lairage environment during the summer and spring is necessary to reduce the thermal load of broiler chickens.

Foundation and Perspectives of the Use of Plant Extracts as Performance Enhancers in Broilers

Feed is responsible for about 70% of broilers production costs, leading to an increasing number of studies on alternative dietary products that benefit bird performance and lower production costs. Since the 1950s, antimicrobial additives are the most frequently used performance enhancers in animal production and their positive results are observed even in high-challenge conditions. Since the 1990s, due to the ban of the use of some antibiotics as growth promoters and the growing trend of the public to consume natural products, plant extracts have been researched as alternatives to antibiotic growth promoters. The first study that evaluated the antibacterial activities of plant extracts was carried out in 1881; however, they started to be used as flavor enhancers only during the next decades. With the emergence of antibiotics in the 1950s, the use of plant extracts as antimicrobial agents almost disappeared. There are several studies in literature assessing the use of plant extracts, individually or in combination, as antimicrobials, antioxidants, or digestibility enhancers in animal feeds. Research results on the factors affecting their action, such as plant variety, harvest time, processing, extraction, as well as the technology employed to manufacture the commercial product and dietary inclusion levels show controversial results, warranting the need of further research and standardization for the effective use of plant extracts as performance enhancers, when added to animal feeds. This article aims at presenting plant extracts as alternatives to antibiotics, explaining their main modes of action as performance enhancers in broiler production.

Evaluation of carcass characteristics of Bos indicus and tropically adapted Bos taurus breeds selected for postweaning weight

Data from 9 studies were compiled to evaluate the effects of 20 yr of selection for postweaning weight (PWW) on carcass characteristics and meat quality in experimental herds of control Nellore (NeC) and selected Nellore (NeS), Caracu (CaS), Guzerah (GuS), and Gir (GiS) breeds. These studies were conducted with animals from a genetic selection program at the Experimental Station of Sertaozinho, Sao Paulo State, Brazil. After the performance test (168 d postweaning), bulls (n = 490) from the calf crops born between 1992 and 2000 were finished and slaughtered to evaluate carcass traits and meat quality. Treatments were different across studies. A meta-analysis was conducted with a random coefficients model in which herd was considered a fixed effect and treatments within year and year were considered as random effects. Either calculated maturity degree or initial BW was used interchangeably as the covariate, and least squares means were used in the multiple-comparison analysis. The CaS and NeS had heavier (P = 0.002) carcasses than the NeC and GiS; GuS were intermediate. The CaS had the longest carcass (P < 0.001) and heaviest spare ribs (P < 0.001), striploin (P < 0.001), and beef plate (P = 0.013). Although the body, carcass, and quarter weights of NeS were similar to those of CaS, NeS had more edible meat in the leg region than did CaS bulls. Selection for PWW increased rib-eye area in Nellore bulls. Selected Caracu had the lowest (most favorable) shear force values compared with the NeS (P = 0.003), NeC (P = 0.005), GuS (P = 0.003), and GiS (P = 0.008). Selection for PWW increased body, carcass, and meat retail weights in the Nellore without altering dressing percentage and body fat percentage.

Characterisation of an antiviral pediocin-like bacteriocin produced by Enterococcus faecium

The bacteriocin-producing strain Enterococcus faecium ST5Ha was isolated from smoked salmon and identified by biomolecular techniques. Ent. faecium ST5Ha produces a pediocin-like bacteriocin with activity against several lactic acid bacteria, Listeria spp. and some other human and food pathogens, and remarkably against HSV-1 virus. Bacteriocin ST5Ha was produced at high levels in MRS broth at 30 degrees C and 37 degrees C, reaching a maximum production of 1.0 x 10(9) AU/ml, checked against Listeria ivanovii ATCC19119 as target strain and surrogate of pathogenic strain Listeria monocytogenes. The molecular weight of bacteriocin ST5Ha was estimated to be 4.5 kDa according to tricine-SDS-PAGE data. Ent. faecium ST5Ha harbors a 1.044 kb chromosomal DNA fragment fitting in size to that of pediocin PA-1/AcH. In addition, the sequencing of bacteriocin ST5Ha gene indicated 99% of DNA homology to pediocin PA-1/AcH. The combined application of low levels (below MIC) of ciprofloxacin and bacteriocin ST5Ha resulted in a synergetic effect in the inhibition of target strain L ivanovii ATCC19119. Bacteriocin ST5Ha displayed antiviral activity against HSV-1, an important human pathogen, with a selectivity index of 173. To the best of our knowledge, this is the first report on Ent. faecium as a potential producer of pediocin-like bacteriocin with antiviral activity. (C) 2010 Elsevier Ltd. All rights reserved.

Natural antioxidants protecting irradiated beef burgers from lipid oxidation

The effect of butylated hydroxytoluene/butylated hydroxyanisole blend (BHT/BHA), and rosemary and oregano extracts, added individually or in combination, on lipid oxidation and fatty acid composition was investigated on irradiated frozen beef burgers. Irradiation treatment was carried out using a (60)CO semi-industrial irradiator at doses of 6, 7 and 8 kGy, and then the treated meat samples were stored at -20 degrees C for 90 days. Lipid oxidation and fatty acid composition of beef samples were evaluated by measurement of TBARS and gas chromatography, respectively. The results of the experiment showed that rosemary extract, applied alone and in combination with either BHT/BHA or oregano extracts was more effective in maintaining a low oxidation level in the samples compared to oregano extract used individually or in combination with BHT/BHA. Results also showed no significant differences (p > 0.05) in fatty acid composition in all analyzed samples, although some changes in terms of decreased PUFA and MUFA, beside of slight increase of SFA content were observed. However, these differences do not correlate positively neither with the irradiation dose nor the type of antioxidant. Thus, there is a potential application of these spices as natural antioxidants in irradiated meats. (C) 2009 Elsevier Ltd. All rights reserved.

High prevalence, low counts and uncommon serotypes of Listeria monocytogenes in linguica, a Brazilian fresh pork sausage

Linguica is a highly popular and appreciated pork product in Brazil, frequently consumed undercooked. Aiming at collection of data for a future risk assessment, this study evaluated the prevalence and counts of Listeria monocytogenes in linguica samples collected at retail level in Sao Paulo, SP, Brazil. ISO methods were used for detection and enumeration of the pathogen (11290-1 and 11290-2, respectively). Isolates were submitted to Simplex-PCR for hlyA gene and those with biochemical features of L. monocytogenes and hlyA positive were serotyped using a Multiplex PCR. Ninety percent of the samples were positive for Listeria spp., and L monocytogenes was detected in 42% of the samples, with counts below 10(2) CFU/g in all samples. A prevalence of uncommon serotypes 4a and 4c was observed. (C) 2009 Elsevier Ltd. All rights reserved.

Effects of natural antioxidants on the lipid profile of electron beam-irradiated beef burgers

The purpose of this study was to assess the efficacy of rosemary and oregano extracts in avoiding oxidative changes in beef burgers, and to evaluate the fatty acid profile of these products after electron beam exposition. Extracts, individually or in combination, were added to beef burgers and compared to synthetic antioxidants commonly used in food (butylated hydroxytoluene, butylated hydroxyanisole). The ground beef were submitted to electron beam irradiation at doses of 0, 3.5 and 7 kGy, and stored for 90 days. At regular time intervals, lipid oxidation and fatty acid composition were evaluated through measurement of thiobarbituric acid-reactive substances (TBARS) and gas chromatography, respectively. The results indicate that, although the irradiation process triggers an increase in the lipid oxidation ratio expressed by TBARS values, great changes in the fatty acid profiles were not observed; instead, they continued to present characteristics very similar to that of non-irradiated beef. Thus, as irradiation doses of up to 7 kGy for frozen meat can make foods safe from foodborne pathogens, natural antioxidants derived from spices are able to reduce and avoid lipid changes that may cause a deterioration of the sensory quality of these foods, and these natural extracts offer a good choice for replacing synthetic additives.

Listeria monocytogenes in two different poultry facilities: Manual and automatic evisceration

Listeriosis is a serious foodborne disease caused by Listeria monocytogenes, a pathogen often found in food processing plants. Poultry meat and its derivatives may harbor L. monocytogenes even if good manufacturing practices are implanted in abattoirs. Little information exists in Brazil on the frequency of L. monocytogenes contamination, even though the country is considered the top poultry meat exporter in the world. This study attempted to compare 2 exporters poultry facilities following same the standards but differing only in manual (plant M) or automatic (plant A) evisceration. Eight hundred fifty-one samples from food, food contact and non-food contact surfaces, water, and workers` hands were collected from cage to finished products over a 1-yr period. In plant A, 20.1% of the samples were positive for L. monocytogenes, whereas in plant M, 16.4% was found. The greatest incidence of contamination with the pathogen in plant A was found in non- food contact surfaces (27.3%), while in plant M, it was found in products (19.4%). The most prevalent serovars were 1/2a or 3a (plant M) and 4b, 4d, or 4e (plant A). Despite having proper hygiene and good manufacturing practices, controlling the entry and persistence of L. monocytogenes in processing facilities remains a formidable task.

Consumer`s evaluation of the effects of gamma irradiation and natural antioxidants on general acceptance of frozen beef burger

The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 degrees C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA formulation obtained the highest score (6.73) and regarding the natural antioxidants, oregano received better acceptance (6.36). Irradiated samples formulated with oregano received a lower score, 6.03 in the first test and 5.06 in the second one, compared to the non-irradiated sample (6.36 and 5.79). In the second test (90 days), the sample formulated with BHT/BHA and which was irradiated received a higher score (6.59) when compared to the non-irradiated one (5.85). In both tests, the irradiated samples formulated with rosemary extract obtained a better score compared to the non-irradiated one, the scores being 5.00-3.82 and 5.00-3.76 in the first and second test, respectively. Our results allowed us to conclude that the natural antioxidants, rosemary and oregano extracts, present a good alternative for replacing synthetic additives in food industries, and that the irradiation process, in some cases, may help to enhance the sensory quality of food. (C) 2008 Elsevier Ltd. All rights reserved.

Evaluation of natural and synthetic compounds according to their antioxidant activity using a multivariate approach

The antioxidant activity of natural and synthetic compounds was evaluated using five in vitro methods: ferric reducing/antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydradzyl (DPPH), oxygen radical absorption capacity (ORAL), oxidation of an aqueous dispersion of linoleic acid accelerated by azo-initiators (LAOX), and oxidation of a meat homogenate submitted to a thermal treatment (TBARS). All results were expressed as Trolox equivalents. The application of multivariate statistical techniques suggested that the phenolic compounds (caffeic acid, carnosic acid, genistein and resveratrol), beyond their high antioxidant activity measured by the DPPH, FRAP and TBARS methods, showed the highest ability to react with the radicals in the ORAC methodology, compared to the other compounds evaluated in this study (ascorbic acid, erythorbate, tocopherol, BHT, Trolox, tryptophan, citric acid, EDTA, glutathione, lecithin, methionine and tyrosine). This property was significantly correlated with the number of phenolic rings and catecholic structure present in the molecule. Based on a multivariate analysis, it is possible to select compounds from different clusters and explore their antioxidant activity interactions in food products.

Effect of natural pigments on the oxidative stability of sausages stored under refrigeration

The objective was to use natural pigments to replace sodium erythorbate (NaEry), a synthetic compound used as an antioxidant in sausage formulations, and to evaluate the oxidative stability of the samples. Six assays were prepared in which sodium erythorbate (ERY) at 0.05 g/100 g was substituted by norbixin (NOR), lycopene (LYC), zeaxanthin (ZEA), beta-carotene (CAR) or dextrose (used as a control (CON)). Physical, chemical, color, texture and sensory parameters were measured on the first day and after 45 days of storage at 4 degrees C. All pigments used in the sausage formulations were able to maintain the oxidative stability of the sausages (MDA equivalents <038 mg/kg). Zeaxanthin and norbixin were the most efficient antioxidants of those tested. This antioxidant effect might be associated with the intermediate polarities of these two compounds, which would allow them to concentrate in the membrane lipids or emulsion interface, where lipid oxidation is most prevalent. Other volatile secondary products of oxidation besides MDA should be evaluated in further studies involving natural pigments and sensory oxidative stability. (C) 2009 Elsevier Ltd. All rights reserved.

Elevated levels of selenium in the typical diet of Amazonian riverside populations

Selenium (Se) intake is generally from food, whose Se content depends on soil Se and plant accumulation. For humans, adequate Se intake is essential for several selenoenzymes. In the Lower Tapajos region of the Brazilian Amazon, Se status is elevated with large inter-community variability. Se intake in this region, where Hg exposure is among the highest in the world, may be important to counteract mercury (Hg) toxicity. The present study was conducted in 2006 with 155 persons from four communities of the Lower Tapajos. The objectives were: i) to evaluate Se content in their typical diet and drinking water; ii) to compare food Se concentrations with respect to geographic location; and iii) to examine the contribution of consumption of different food items to blood Se. More than 400 local foods and 40 drinking water samples were collected. Participants responded to an interview-administered food frequency questionnaire and provided blood samples. Food, water and blood Se levels were assessed by ICP-MS. Since Brazil nuts may also contain significant levels of barium (Ba) and strontium (Sr), these elements were likewise analyzed in nuts. The highest Se concentrations were found in Brazil nuts, but concentrations were highly variable (median: 13.9 mu g/g; range: 0.4-158.4 mu g/g). Chicken, game meat, eggs and beef also contained considerable levels of Se, with median concentrations from 0.3 to 1.4 mu g/g. There was no particular geographic distribution of food Se. Se concentration in drinking water was very low (<1.4 mu g/L). Blood Se covered a (103-1500 mu g/L), and was positively related to regular consumption of Brazil nuts, domestic chicken and game meat. Brazil nuts were found to contain highly variable and often very high concentrations of Ba (88.0 mu g/g, 1.9-1437 mu g/g) and Sr (38.7 mu g/g, 3.3-173 mu g/g). Further studies should address multiple nutrient/toxic interactions in the diet and related effects on health. (c) 2010 Elsevier B.V. All rights reserved.

Lactobacillus sakei 1 and its bacteriocin influence adhesion of Listeria monocytogenes on stainless steel surface

Listeria monocytogenes is of particular concern for the food industry due to its psychrotolerant and ubiquitous nature. In this work, the ability of L monocytogenes culturable cells to adhere to stainless steel coupons was studied in co-culture with the bacteriocin-producing food isolate Lactobacillus sakei 1 as well as in the presence of the cell-free neutralized supernatant of L sakei 1 (CFSN-S1) containing sakacin 1. Results were compared with counts obtained using a non bacteriocin-producing strain (L sakei ATCC 15521) and its bacteriocin free supernatant (CFSN-SA). Culturable adherent L monocytogenes and lactobacilli cells were enumerated respectively on PALCAM and MRS agars at 3-h intervals for up to 12 h and after 24 and 48 h of incubation. Bacteriocin activity was evaluated by critical dilution method. After 6 h of incubation, the number of adhered L monocytogenes cells in pure culture increased from 3.8 to 5.3 log CFU/cm(2) (48h). Co-culture with L sakei 1 decreased the number of adhered L monocytogenes cells (P < 0.001) during all sampling times with counts lower than 3.0 log CFU/cm(2). The CFNS-S1 also led to a significant and similar reduction in culturable adhered L. monocytogenes counts for up to 24 h of incubation, however after 48 h of incubation, re-growth of L monocytogenes number of adhered cells was observed, likely due to lack of competition for nutrients. L sakei ATCC 15521 or its supernatant (CFNS-SA) did not reduce the number of adhered L monocytogenes cells on stainless steel surface and from 6 h of incubation, listerial counts were between 4.3 and 4.5 log CFU/cm(2). These results indicate that L sakei 1 and its bacteriocin sakacin 1 may be useful to inhibit early stages of L monocytogenes adherence to abiotic surface. (C) 2011 Elsevier Ltd. All rights reserved.

Prevalence and characterization of Enterococcus spp. isolated from Brazilian foods

Enterococci can be used in the food industry as starter or probiotic cultures. However, enterococci are also implicated in severe multi-resistant nosocomial infections. In this study, the prevalence of enterococci in selected Brazilian foodstuffs (raw and pasteurized milk, meat products, cheeses and vegetables) was evaluated. Phenotypic and PCR protocols were used for species identification. Tests for production of gelatinase, haemolysin, bacteriocin and bile salt hydrolysis were done with all enterococci isolates, whereas molecular determination of virulence markers (genes esp, gel, ace, as, efaA, hyl and cylA) and antibiotic resistance was checked only for Enterococcus faecium and Enterococcus faecalis isolates. The antibiotic-resistant isolates were assayed for biofilm formation and adhesion to mammalian cells. From the 120 food samples analyzed, 52.5% were positive for enterococci, meat and cheese being the most contaminated. E. faecium was the predominant species, followed by E. faecalis, E. casseliflavus and Enterococcus gallinarum. Phenotypic tests indicated that 67.7% of isolates hydrolyzed bile salts, 15.2% produced bacteriocin, 12.0% were beta-hemolytic and 18.2% produced gelatinase. Antibiotic resistance (gentamicin, tetracycline and erythromycin) and genes encoding for virulence traits were more frequent in E. faecalis than in E. faecium. Three E. faecium isolates were resistant to vancomycin. Among antibiotic-resistant isolates, 72.4% of E. faecalis were able to form biofilm and 13.8% to adhere to Caco-2 cells. Antibiotic-resistant E. faecalis and E. faecium isolates were grouped by RAPD-PCR and a scattered distribution was noted, indicating that resistance was not related to a particular clone. The spread of virulence/resistance traits in isolates of the two species and different RAPD-types suggest the pathogenic potential of both species. By contrast, the recovery of bacteriocinogenic E. faecium isolates with no virulence traits suggests their potential for biotechnological applications. In conclusion, our results showed that enterococci from Brazilian foods present important dualist aspects for food safety. (C) 2008 Elsevier Ltd. All rights reserved.

Communism and Public Opinion in Queensland, 1939-1951 : An Explanation of Queensland's Vote in the 1951 Anti-Communist Referendum

The starting point of this thesis was a desire to explain the rapid demise in the popularity which the Communist Party enjoyed in Queensland during the second world war. Wartime Queensland gave the Australian Communist Party its highest state vote and six years later Queensland again gave the Communist Party its highest state vote - this time however, to ban the Party. From this I was led into exploring the changing policies, beliefs and strategies of the Party, as well as the many sub-groups on its periphery, and the shifts in public response to these. In 1939 Townsville elected Australia's first Communist alderman. Five years later, Bowen elected not only Australia's first but also the British Empire's first, Communist state government member. Of the five electorates the Australian Communist Party contested in the 1944 Queensland State elections, in none did the Party's candidate receive less than twenty per-cent of the formal vote. Not only was the Party seemingly enjoying considerable popular support but this was occurring in a State which, but for the Depression years (May 1929 - June 1932) had elected a Labor State Government at every state election since 1915. In the September 1951 Constitution Alteration Referendum, 'Powers To Deal With Communists and Communism', Queensland regist¬ered the nation's highest "Yes" majority - 55.76% of the valid vote. Only two other states registered a majority in favour of the referendum's proposals, Western Australia and Tasmania. As this research was undertaken it became evident that while various trends exhibited at the time, anti-Communism, the work of the Industrial Groups, Labor opportunism, local area feelings, ideological shifts of the Party, tactics of Communist-led unions, etc., were present throughout the entire period, they were best seen when divided into three chronological phases of the Party's history and popularity. The first period covers the consolidation of the Party's post-Depression popularity during the war years as it benefited from the Soviet Union's colossal contribution to the Allied war efforts, and this support continued for some six months or so after the war. Throughout the period Communist strength within the trade union movement greatly increased as did total Party membership. The second period was marked by a rapid series of events starting in March 1946, with Winston Churchill's "Official Opening" of the Cold War by his sweeping attack on Communism and Russia, at Fulton. Several days later the first of a series of long and bitter strikes in Communist-led unions occurred, as the Party mobil¬ized for what it believed would be a series of attacks on the working class from a ruling class, defending a capitalist system on the verge of an economic collapse. It was a period when the Party believed this ruling class was using Labor reformism as a last desperate 'carrot' to get workers to accept their lot within a capitalist economic framework. Out of the Meat Strike emerged the Industrial Groups, who waged not only a determined war against Communist trade union leadership but also encouraged the A.W.U.-influenced State Labor apparatus to even greater anti-Communist antagonisms. The Communist Party's increasing militancy and Labor's resistance to it, ended finally in the collapse of the Chifley Labor government. Characteristically the third period opens with the Communist Party making an another about-face, desperately trying to form an alliance with the Labor Party and curbing its former adventurist industrial policy, as it prepared for Menzies' direct assault. The Communist Party's activities were greatly reduced, a function of both a declining member-ship and, furthermore, a membership reluctant to confront an increasingly hostile society. In examining the changing policies, beliefs and strategies of the Party and the shifts in public response to these, I have tried to distinguish between general trends occurring within Australia and the national party, and trends peculiar to Queensland and the Queensland branch of the Party, The Communist Party suffered a decline in support and membership right across Australia throughout this period as a result of the national policies of the Party, and the changing nature of world politics. There were particular features of this decline that were peculiar to Queensland. I have, however, singled out three features of particular importance throughout the period for a short but more specifically detailed analysis, than would be possible in a purely chronological study: i.e. the Party's structure, the Party's ideological subservience to Moscow, and the general effect upon it of the Cold War.