Abstract in English:The objective this study was to assess ergonomic factors, posture and biomechanics of workers of a broiler egg hatchery. The analysis of ergonomic factors was based on physical work load, thermal environment, and exposure to light and noise. The posture of workers was analyzed using photographic records which were evaluated by the software program OWAS (Ovako Working Posture Analysing System). A biomechanics analysis was also performed based on the photographs taken of the employee at various angles, which were used as inputs to the Michigan two-dimensional biomechanical model software program. The results show that certain activities can be considered unhealthy due to the exposure of employees to physical and thermal overload. The continuous noise levels and lighting were outside the range considered adequate by the regulations of the Brazilian Ministry of Labor. The manner in which certain activities are carried out when associated with weight and poor posture can result in body lesions in broiler hatchery employees. It is therefore necessary to apply specific ergonomic programs, including scheduled breaks, training, and other measures in order to reduce or to eliminate the risks involved in these activities.
Abstract in English:The objective of this study was to investigate the appropriate temperature for processing storage of chicken meatballs made of minced chicken meat with the sous vide method. The chicken meatballs were prepared and separated into four experimental groups according to the application of heat treatment (10 and 20 minutes) and storage time (+2 and +10°C). Sensory, microbiological (total aerobic mesophilic bacteria, total psychrotrophs, lactic acidbacteria, Enterobacteriaceae, Clostridiumperfringens, Listeria spp.), chemical (pH, thiobarbituric acid), color (L*, a*, b* values), and texture profile analyses were performed on meatball samples. Cl. perfringens and Listeria spp. were not detected in meatball samples during the storage period. Samples cooked at 10 minute and stored at +2°C the highest count of total aerobic mesophilic bacteria (p<0.05). For lipid oxidation, interaction was observed between cooking time and storage temperature, with higher TBARs values for samples stored at 10 °C, while cooking time and storage temperature showed no influence on the color and textural analysis parameters. For the treatments evaluated, cooking time x storage temperature seem affect more microbiological and chemical parameters than color and textural parameters of chicken meatballs.
Abstract in English:Brazilian poultry production is very efficient and demands maximum broiler performance. Therefore, digestive system pathologies have a relevant role. Considering it is difficult to obtain consistent information on intestinal morphometric analysis, this study aimed at establishing essential and clear criteria for the collection of intestinal segments for morphometric analysis. Fifteen 13-d-old broilers were sacrificed and three intestinal segments were collected per bird. Two 3-cm long sections were obtained from each of the intestinal segments. Samples were collected open or closed. The closed samples were transversely, hemicylindrically, or longitudinally sectioned. Samples were processed and stained with hematoxylin and eosin. The number of microscopic fields in each section was counted. Villi presenting the base clearly embedded in the submucosa, no damage or folds, and simple columnar epithelium at the tip were considered adequate for measurements. These villi were counted in each sample. The results shows that hemicylindrical sections presented the highest number of observation fields, with an average of 9.76 fields. Jejunum samples were among the three highest average villi counts, with 18.23 in longitudinal sections and 15.61 in hemicylindrical sections. The results of the present study indicate that hemicylindrical sectioning and jejunal samples were, respectively, the best sectioning method and the best intestinal segment for the morphometric analysis of the intestines of broilers.
Abstract in English:The aim of this study was to evaluate bacteriological characteristics and shelf life of three formulations of ostrich sausages (linguiças), only differing in lean meat percentage: Formula 1, 100% ostrich meat; Formula 2, 75% ostrich meat + 25% pork; and Formula 3, 50% ostrich meat + 25% pork + 25% chicken. All linguiças were vacuum-packed and stored at 5 ± 2ºC. Mesophilic and psychrotrophic bacteria, sulfite-reducing Clostridia, coagulase-positive Staphylococci, and Escherichia coli were enumerated and Salmonella spp were isolated and identified. Initial mesophilic and psychotropic bacteria counts were high. During storage time, sulfite-reducing Clostridia, coagulase-positive Staphylococci, and Escherichia coli counts never reached the tolerance limit established by the Brazilian legislation. However, Salmonella was isolated from a Formula 2 sample on day 1, therefore, it was considered inappropriate for consumption. The shelf lives of Formulas 1 and 3 were below 12 and 8 days, respectively. If initial bacterial counts had been lower, the shelf life of the evaluated formulas would probably be longer. This study showed that ostrich meat trimmings can be successfully used in the production of ostrich linguiças, and that the formula containing ostrich meat as the only source of lean meat presented the longest shelf life.
Abstract in English:Although the use of probiotics especially Lactobacillus and Bifidobacteria species on growth and feed utilization in poultry production has been extensively studied, the results were inconsistent presumably because the mode of action of probiotic is multi-factorial and each probiotic strain may affect the host in a specific manner. This study investigated the probiotic effect of two strains of Lactobacillus (Lactobacillus pentosus ITA23 and Lactobacillus acidophilus ITA44; 109 cells/kg feed) isolated from mulberry (Morus Alba) silage on the growth performance, cecal microbial population, and blood cholesterol of broiler chickens. One hundred twenty male broiler chicks (Cobb500) were randomLy allocated to two groups (control and treatment) of six replicates (cages) with 10 chicks per cage. Chicks in the control group received a standard diet and those in the treatment group received the same diet supplemented with 109 cells of the above Lactobacillus per kg feed. Supplementation of Lactobacillus did not affect body weight gain (averaged 1604 g at 35 days old) but feed conversion ratio improved (p<0.01) by 6.4% due to reduction in feed intake (p<0.01) by birds in the treatment group. Supplementation also increased the population of Lactobacillus spp. and reduced pathogens E. coli in the cecal samples. Although Lactobacillus supplementation tends to reduce serum total cholesterol, low-density lipoprotein (LDL) and triglyceride concentrations, these values were not significantly different from those of the control group. Results of this study showed that L. pentosus ITA23 and L. acidophilus ITA44 are potential probiotics to be used in poultry diets.
Abstract in English:Freezing is one of the methods to preserve and guarantee the quality of meat until it reaches the consumer. Even though freezing is classified as a mild form of preservation, it causes meat changes resulting from the formation of ice crystals that subsequently affect the tenderness and functionality of meat. The aim of this study was to evaluate the physicochemical and structural characteristics of chicken half breast submitted to fast freezing (-36 °C for 2 hours) and thawed by five different methods (under refrigeration, in a microwave, in a oven with air circulation, placed in cold water, or at room temperature). After thawing, the following parameters were evaluated: moisture content, drip loss (syneresis), water activity (aw), and shear force. Samples were also histologically evaluated by light microscopy. The results indicated that, despite being submitted to fast freezing, thawing affected (p <0.05) most of the physicochemical and structural properties of the meat, except for aw. Thawing in cold water (packed in low-density polyethylene bags and placed in cold water at approximately 10 °C for 2 hours and 15 minutes) presented the best results due to lesser damage to the cell structure, as shown by the lower drip loss, higher moisture content, and greater tenderness of the samples compared to those thawed using the other methods. Histological examination showed that muscle fiber structural features and organization were maintained. Thawing at low temperatures seems to cause less damage to the meat structure and allows maintaining of its properties. It was concluded that the meat quality is not related only with the freezing method, but also with the method and conditions used in thawing.
Abstract in English:Nutritionists need to make commercial decisions about the optimal nutrient content broiler feeds. In order to demonstrate that broiler prices may influence dietary nutrient density, this study developed quadratic feed intake and weight gain equations, according to broiler sex and feeding phase, to be applied in a nonlinear feed formulation model. Four hundred and eighty Cobb broilers were allotted to a completely randomized experimental with six treatments, each with four replicates of 10 birds each, from 1 to 56 days old. Treatments consisted of diets containing 2800, 2900, 3000, 3100, 3200, or 3300 kcal metabolizable energy (ME)/kg and constant nutrient to ME ratio. A nonlinear version of the PPFR feed formulation software (http://www.fmva.unesp.br/ppfr) was developed with the objective of optimizing energy density and bird performance. According to the results, when the models are applied in the PPFR nonlinear spreadsheet, the most favorable nutrient density content is defined by mathematical models, as optimized by the Excel Solver tool by means of cost/benefit comparisons and as a function of rearing phase (starter, grower, and finisher) and sex. This contradicts the recommendations of genetic company manuals and published requirement tables, whose goal is to maximize weight gain and do not necessarily guarantee maximum economic efficiency.
Abstract in English:Dose-dependent positive effects on hatchability and hatchling weight have been attributed to ascorbic acid (AA) when eggs were submitted or not to intermittent heat stress during incubation. Fertile breeder (Cobb(r)) eggs were used to determine if the pre-incubation injection of AA in ovo affects the incubation and hatchling quality of egg incubated under thermoneutral or intermittent heat stress conditions. Eggs were not injected or injected with 0, 2,4, or 6% AA/100µL water and incubated at continuous thermoneutral (37.5ºC) or hot (39.0ºC) temperature. Eggshell temperature (EST) increased in the second half of the incubation period in all experimental groups. The EST of non-injected eggs and of those injected with water was higher when incubated at 39°C than at 37.5°C, but EST was not different among eggs injected with AA. Egg mass loss and eggshell conductance were higher in the eggs incubated at 39°C than at 37.5°C.Hatchability was lower in the eggs injected with AA. Liver and yolk sac weights were higher, whereas heart and liver weights were lower in hatchlings from eggs incubated at 39°C; however, hatchling weight was not affected by incubation temperature. The results showed that AA doses affected egg conductive heat loss and hatchability, and that they did not minimize the effects of high incubation temperature on liver and heart development.
Abstract in English:An experiment was conducted to evaluate the effect of an enzyme blend (EB) on the performance, diet metabolizability, phosphorus (P) retention, and bone mineralization of broilers fed diets containing 10% defatted rice bran (DRB). In total, 432 one- to 38-d-old male Cobb broilers were evaluated according to a completely randomized experimental design in 3 x 2 factorial arrangement. Three diets were tested with two nutrient reductions (NR) in the matrix (standard diet; NR I of 75 kcal/kg ME, 0.1% Ca and 0.1% available P; and NR II of 100 kcal/kg ME, 0.1% Ca and 0.1% available P) with or without the addition of an EB (200 g/t). The coefficients of total tract apparent retention (CTTAR) of the diets and P retention were determined by collecting excreta during two periods (14 to 17 and 28 to 31 d). As expected, birds fed the standard diet had higher BW, BW gain, and G:F compared to birds on the NR diets. The EB did not show any positive effects on CTTAR or on performance; however, birds fed the EB retained 6.58% more P from d 14 to 17 (p ≤ 0.07) and 8.55% from d 28 to 31 (p < 0.05). Tibiotarsus ash percentage also increased by 2.45% (p ≤ 0.06) on d 38. In diets containing 10% DRB, the enzyme blend showed biological activity improving P retention and tibiotarsus mineralization.
Abstract in English:In this study, one hundred and twenty 40-wk-old White Leghorn laying hens were submitted to two different thermal conditions (24° C vs. 34° C) and were fed three levels (0, 10, or and 20 g/kg of diet)of fennel fruits (Foeniculum vulgare Mill.) as a feed additive in. This study was carried out according to a factorial design consisting of two temperatures and three fennel levels with five 5 replicates each (n = 2 × 3 × 5). Performance, egg production, egg quality, and oxidative product levels (malondialdehyde, MDA, and carbonyl) in the eggs were measured before and after heat exposure. The results showed that the tested temperatures did not affect egg production (p>0.05), but the production of eggs with broken shell and feed intake were affected by heat stress (p<0.05). The different temperatures also affected egg quality (p<0.05), reducing egg weight (EW), eggshell thickness (EST), eggshell strength (ESS), Haugh units (HU), albumen height (AH), and albumen weight (AW). At the high environmental temperature, MDA and carbonyl egg contents increased (p<0.05), while fennel consumption reduced the values of both parameters. Heat stress had no effect on yolk cholesterol levels (p>0.05), but increased yolk triglyceride levels. Hens that consumed fennel presented lower yolk cholesterol and triglyceride levels (p<0.05). In general, fennel fruit influenced egg yolk cholesterol and triglyceride contents, and because of its antioxidant properties, it may alleviate the adverse effects of heat stress on laying hens.
Abstract in English:Growth curves for the uropygial gland (UG) of white, 3-way crossed mule ducklings were established using the Gompertz function. In total, 144 ducklings were fed in 12 floor pens with 12 birds in each pen. Each pen contained an equal number of animals of each sex. Feed and water were supplied ad libitum throughout the entire experimental period. The weekly change in UG weight was recorded in males and females from hatch to 8 weeks of age. The weight and length of the UG, the width of the lobus glandulae uropygialis, the length and width of the pluma of the circulus uropygialis, and the index of the papilla uropygialis were measured once a week in individual ducklings in one pen. The average UG weight gain observed in white, 3-way crossed drakes was significantly higher than that of ducks of 21-56 days of age (P < 0.05). The UG length was 1.64-2.23 times the width of the left or right lobe, and the development of the UG was delayed from 3-4 weeks of age. The morphology of the UG changed from elliptical to elongated-elliptical with age. The right and left lobus glandulae uropygialis were symmetrical. The Gompertz growth functions of the UG in drakes and ducks were W=5.49e -e-0.675(t-1.955) and W=4.76e -e-0.685(t-1.936), respectively, where t represents age in weeks. These equations indicated that the maximum growth rate for drakes occurred at 14.1 days of age and for ducks at 13.6 days of age.
Abstract in English:Light is an important environmental variable for the regulation and control of broiler behavior. Some light sources may also add heat to the rearing environment, and indirectly affect the heat exchange between the birds and the environment. This study aimed at investigation the surface temperature and behavioral response of broilers reared in an environment with monochromatic light emitted diode (LED). Broilers were reared inside commercial dark houses under two treatments: fluorescent or LED light sources. Bird surface temperature and behavior was monitoredfrom the first day of grow-out. The houses were virtually divided in four quadrants, and the variables were monitored in the geometric center of each quadrant. Surface temperature results were mapped, behavioral responses were divided as normal and abnormal, and their interaction with light source was tested. Broiler surface temperature in both houses presented lack of homogeneity, independently of the light source. No effect of the light source on any of the evaluated behavior was found in the present study. The long life and energy savings obtained with the LED light source suggest its use in broiler production.
Abstract in English:A trial was conducted to evaluate the effects of adding an exogenous α-amylase-β-glucanase complex produced from Bacillus amyloliquefaciens on the growth performance, carcass yield, and relative AME bioequivalence in broilers fed corn-soy diets from 1 to 40 d of age. One thousand seven hundred and fifty one-day-old Cobb x Cobb 500 slow-feathering male broilers were randomly allotted to seven treatments with 10 replicates of 25 birds each as follows: control diet (C); C diet with reduction of 60 (C-60), 90 (C-90), or 120 (C-120) kcal AME/kg; C diet with reduction of 120 kcal AME/kg and supplemented with 200 (C-120-200), 300 (C-120-300), or 400 (C-120-400) mg of the enzyme complex/kg. Each g of the enzyme complex corresponded to 200 kilo-Novo α-amylase and 350 fungal β-glucanase units. On d 40, eight birds were randomly taken from each pen and processed to evaluate carcass and commercial cuts yields. Percent mortality was not affected by the treatments (p > 0.05). Live performance, as indicated by BW gain (BWG) linearly decreased (p < 0.05) and FCR linearly increased with the reduction in AME. Birds fed diets supplemented with the enzyme complex showed weekly improvements in BWG and FCR. There were no effects of the treatments on the yield of the carcass or of commercial cuts; however, abdominal fat was significantly lower (p < 0.0343) in birds fed the C-120-400 compared to the C-120 feeding program (1.67% vs. 1.90%); all other treatments were intermediate. Average AME equivalence of the enzyme complex varied weekly. Estimations for the entire period were 40, 46, and 56 kcal for BWG and 58, 76, and 99 kcal AME/kg for FCR (p < 0.001) for the diets containing 200, 300, and 400 mg enzyme complex/kg, respectively.
Abstract in English:Several physiological and metabolic changes are triggered in broilers submitted to high environmental temperatures, resulting in performance losses. Feed formulation manipulation of the dietary electrolyte balance may be applied to reduce the negative impact of heat stress on broiler performance. This experiment was carried out to evaluate the effect of the manipulations of dietary electrolytes by combining changes in the electrolyte (Na++K+-Cl-) balance (EB) and in the [(K++Cl-)/Na+] ratio (ER) in broiler feeds. In total, 1575 male broilers between 21 and 46 days old were allotted to 15 treatments in a 5x3 factorial arrangement, consisting of five diets with different EB/ER combinations (150/3, 250/2, 250/3, 250/4, and 350/3). Birds were submitted to heat stress at 25 or 35 days old. Live performance, mortality rate, and carcass traits were evaluated. The strategic formulation of diets with different EB and ER improves live performance and minimize the effect of heat stress on broilers. Under thermoneutral conditions, an EB of 250 mEq/kg and an ER of 3 are recommended, whereas under heat stress, and EB of 350 mEq/kg and an ER of 3 should be applied.
Abstract in English:Two experiments were conducted to evaluate the nutritional quality of two sources of low-oil distiller's dried grains with solubles (DDGS) and their pigmenting ability for broiler chicken skin and egg yolks. In Experiment 1, 360 Bovan-White hens between 69 and 77 weeks of age were randomly assigned to five dietary treatments with 6 replicates of 12 hens each. In Experiment 2, 375 Ross 308 broiler chickens were randomly assigned to five treatments with three replicates of 25 birds each. The chickens were fed the experimental diets from one to 42 d of age. In both experiments, treatments consisted of a basal diet with no DDGS, and diets with 6% or 12% inclusion of DDGS from two sources. In Experiment 1, no significant differences in performance were detected among treatments (p> 0.05). Egg yolk pigmentation, according to CR-400 Minolta Colorimeter redness (a) and yellowness (b), linearly increased (p<0.05) with DDGS inclusions. In Experiment 2, no significant differences (p>0.05) were detected among treatments in growth performance, carcass yield, or abdominal fat at 42 d of age. Yellowness linearly increased (p<0.05) in the skin and abdominal fat of the birds that consumed diets with DDGS. The results of the current study indicate that feeding two sources of low-oil DDGS to broiler chicks or laying hens does not negatively affect egg production or growth performance while improves egg yolk and skin yellowness.
Abstract in English:The objective of this study was to evaluate the effects on gamma radiation levels on the physical and microbiological characteristics of chicken breast meat. A completely randomized experimental design in a 4x2x3 factorial arrangement was adopted. Treatments consisted of four radiation concentrations (0, 2, 4, or 8kGy), two package sealing methods (with or without vacuum), and three storage times (01, 07, or 14 days), with ten replicates each, totaling 240 chicken breast fillets. Packaging and radiation had no influence (p>0.05) on chicken breast meat pH, water retention capacity, or presence of Salmonella spp. Breast fillets not submitted to radiation and vacuum packed presented higher water retention capacity (p<0.05) than those radiated at 4kGy and vacuum packed. Drip loss in fillets radiated at 8kGy and not vacuum packed was higher (p<0.05) than in non-radiated and non-vacuum packed fillets; however, both were not different from the other treatments. Coliform presence increased with storage time in non-radiated samples; however, when these were vacuum-packed, their development was slower. The results of the present experiment suggest that the use of a low radiation dose (2kGy), combined with vacuum packing, may minimize the harmful effects of storage on chicken breast fillets.
Abstract in English:Toxoplasma gondii and Neospora caninum are two intracellular apicomplexan protozoa with worldwide distribution, and are responsible for reproductive disorders in sheep and cattle. These protozoa may infect a wide variety of domestic and wild animals, including birds, and backyard chickens can be used as sentinels of their infection. Parasites investigation in backyard chickens may be useful for the evaluation of environmental contamination with oocysts, of the disease cycle, and of risk factors associated with public health. The aim of this study was establish the importance of backyard chickens as T. gondii and N. caninum hosts. A number of 137 serum samples were collected from chickens in 23 farms in Rio Grande do Sul State, Brazil, and tested for toxoplasmosis and neosporosis by indirect fluorescence antibody test (IFAT). Anti-Toxoplasma and anti-Neospora antibodies were detected in 20 (87%) farms. Total prevalence of T. gondii was 74.4% (102/137) and 36.5% (50/137) for N. caninum, while 12.4% (17/137) of the chickens were positive for both protozoa. The results show that backyard chicken can used as indicators of the presenced of the protozoa N. caninum and T. gondii, emphasizing yours importance in the public health. Considering the high prevalence of toxoplasmosis in backyard chickens in the region, control measures should be taken to prevent transmission of the infection to the animals and humans.