Abstract in English:ABSTRACT The need to comply with animal welfare has motivated the research for non-invasive methods that allow the evaluation of poultry and eggs to be painless while providing accurate measurements. In this scenario, bioelectrical impedance was tested as a minimally invasive tool for sexing day-old chicks of two different chicken strains and for evaluating the quality of eggs submitted to different days of storage relative to their hatchability. The resistance and phase angle measured allowed the differentiation between chicken strains, but not between sexes. Eggs stored for seven days showed higher resistance and lower phase angle those stored for only one day. Although the bioimpedance method seems to be a promising method to evaluate egg and chick quality, the results of the present study suggest that further studies are needed to validate its utilization, particularly in terms of electrode type and positioning, as well as for the determination of which electrodes and equipment are best suited for different evaluation purposes.
Abstract in English:ABSTRACT The objective of the study was to evaluate the effect of nutritional plans on the productive and economic performance of Hubbard Flex broiler chickens. A completely randomized experimental design was applied, consisting of five treatments. Treatments consisted of five different nutritional plans: a basal diet containing the nutrient and energy levels recommended by literature and designated reference diet; two diets containing 1.5% and 3% lower levels than the reference diet; and two diets containing 1.5% and 3% higher levels than the reference diet (-3%, -1.5%, reference plan, +1.5% and +3%). Feed intake (FI), body weight (BW), feed conversion rate (FCR), livability (L) and productive efficient index (PEI) were determined when broilers were 42 days old. Broilers were processed, and carcass and parts (breast fillet, leg, and wings) yields were determined. The economic viablility of the nutitional plans was evaluated as a function of feed cost/kg live and carcass weights, economic efficiency index (EEI), and cost index (CI). Feed intake and the feed conversion rate decreased as dietary nutrient and energy levels increased. Feed cost/kg live weight, economic efficiency index, and cost index cost increased as dietary nutrient and energy levels increased. Feed intake, feed conversion ratio, production efficiency index, and breast yield improved with increasing nutritional and energy levels. However, worse economic results were obtained with higher nutritional and energy levels.
Abstract in English:ABSTRACT In poultry processing plants, disinfectants are often added to pre-chilling water tanks to reduce microbial contamination. The present study aimed at evaluating the effect of five disinfectants (acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride, chlorine dioxide, peracetic acid, and sodium hypochlorite) on the populations of food quality indicator microorganisms and on Salmonella Enteritidis (SE) in the presence and absence of organic matter. The results showed that chlorine dioxide and sodium hypochlorite did not reduce microbial carcass counts. On the other hand, acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid reduced total and fecal coliform counts. Peracetic acid reduced the number of psychrotrophic microorganisms. All products were effective in reducing SE counts only in the absence of organic matter. Acidified sodium chlorite, alkyl dimethyl benzyl ammonium chloride and peracetic acid could be candidates for the replacement of sodium hypochlorite (commonly used in Brazil) in pre-chilling tanks.
Abstract in English:ABSTRACT This study aimed at proposing a new technical criteria for condemnation of turkey carcasses due to fowlpox in turkeys as a contribution for the work of the Brazilian Federal Meat Inspection Service. Skin samples from 30 carcasses of a flock of 840 turkeys (Meleagris gallopavo), previously vaccinated for fowlpox and slaughtered in June 2013, were collected. Samples were submitted to histological examination under light microscopy. The virus was identified using standard PCR techniques. The main histological findings were hyperplasia and hydropic degeneration of the epithelium and the presence of intracytoplasmic eosinophilic inclusion bodies. PCR results yielded 83.3% positive and 16.7% negative samples. Fowlpox virus is species specific, and there are no reports of its occurrence in mammals. The macroscopic and microscopic findings of the skin lesions do not justify the total condemnation of carcasses of poultry affected with fowlpox, except in cases of cachexia or repulsive appearance, as established by SIF regulation.
Abstract in English:ABSTRACT Two experiments were done to evaluate the effect of increasing levels of dietary digestible methionine (Met) and Met:cysteine (Met:Cys) ratio on the productivity of Hy-Line W-36 laying hens fed sorghum- and soybean meal-based diets. In Exp. 1, 160 hens from 68 to 75 weeks of age were assigned to four dietary levels of digestible Met (0.20 0.24, 0.28 and 0.32%). The digestible total sulfur amino acids:Lysine (TSAA:Lys) ratios were: 62, 68, 76 and 84%. In Exp. 2, 192 hens from 76-83 weeks of age were assigned to four dietary digestible Met:Cys ratios (160, 116.7, 85.7 and 62.5%). The digestible TSAA:Lys ratio was kept constant across diets (80%). Results were subjected to ANOVA and linear regression analyses. In Exp. 1, optimal egg production, egg mass, and feed efficiency responses were observed at 0.30 and 0.50% of dietary digestible Met and TSAA, respectively (quadratic effect, p<0.05). Live performance was maximized with digestible Met and TSAA in takes of 288 and 478 mg/hen/d, respectively. In Exp. 2, optimal egg production and feed efficiency responses were observed at 151 and 150% of dietary digestible Met:Cys ratios, respectively (quadratic effect, p<0.05). The digestible Met, Cys and TSAA intake to maximize egg production and feed efficiency were 313, 207 and 510 mg/hen/d, respectively. The requirements for sulfur AA in Hy-Line W-36 hens from 68 to 83 weeks of age fed sorghum- and soybean meal-based diets fell inside the range of the requirements previously estimated in hens fed corn-soybean meal based diets.
Abstract in English:ABSTRACT In total, 216 Hy-Line brown laying hens (40-week-old), were used in a 5-week experiment to evaluate the effects of ionized or chelated water-soluble mineral mixture supplementation on live performance, nutrient digestibility, blood characteristics, egg quality, and excreta microbiota. Layers were randomly assigned to one of three dietary treatments with 12 replicates of six adjacent cages each. The dietary treatments consisted of: 1) CON (basal diet + normal tap water), 2) T1 (CON+0.5% ionized mineral mixture in tap water, pH 3.0); and 3) T2 (CON+ 0.5% chelated mineral mixture in tap water, pH 3.0). Egg production tended to increase in week 1, week 3 and week 4 in the birds supplemented with T1 and T2 diet compared with CON. Moreover, the dietary supplementation of water-soluble mineral mixture improved (p=0.02) eggshell thickness in week 4 and tended to improve in week 5 of the experimental period in T2 hens compared with CON. The layers fed the T1 diet presented higher (p<0.05) Ca digestibility than CON hens, while the T2 diet promoted a numerical increase in Ca digestibility. Blood calcium concentration increased (p<0.05) with T1 and T2 treatments compared with CON. The laying hens fed the T1 and T2 diets tended to present lower Salmonella and E. coli counts isolated from excreta compared with CON. In conclusion, ionized and chelated mineral mixtures had a positive impact on production performance and eggshell quality, improved Ca digestibility and blood Ca level.
Abstract in English:ABSTRACT Housing environment is essential to achieve good broiler performance and to prevent diseases, including footpad dermatitis (FPD). The objective of this study was to determine the incidence of footpad dermatitis in broilers chickens according to housing type. The study was carried out with broilers reared for 5, 12, 19, 29 and 40 days. Four houses were used in this observational study. House 1 (A1) had positive pressure and reused litter; house 2 (A2) had positive pressure and new litter (sawdust); house 3 (A3) had positive pressure and new litter (rice husks); and house 4 (A4) had negative pressure and reused litter. During the entire experiment, air environmental and litter surface temperatures, and litter compaction were recorded. Pododermatitis was assessed by visual scoring of the footpads. Footpads were scored as function of the severity of the lesion. The comparison of means by the test of Bonferroni at 95% confidence interval showed higher incidence of footpad dermatitis in A3, probably due to the particle size of litter substrate. The lowest footpad dermatitis incidence was found in A1, with reused sawdust litter.
Abstract in English:ABSTRACT Although Pasteurella multocida is a member of the respiratory microbiota, under some circumstances, it is a primary agent of diseases , such as fowl cholera (FC), that cause significant economic losses. Experimental inoculations can be employed to evaluate the pathogenicity of strains, but the results are usually subjective and knowledge on the pathogenesis of this agent is still limited. The objective of this study was to establish a new methodology for classifying the pathogenicity of P. multocida by formulating a standard index. Strains isolated from FC cases and from swine with respiratory problems were selected. One hundred mL of a bacterial culture of each strain, containing 106 CFU, was inoculated in 10 one-day-old broilers. Mortality after inoculation, time of death (TD), and the presence of six macroscopic lesions were evaluated over a period of seven days post-inoculation (dpi). A Pathogenicity Index Per Bird (IPI), ranging 0 to 10, was calculated. Liver and heart fragments were collected to reisolate the bacteria. Blood was collected from the surviving birds, and an ELISA test was carried out to detect specific antibodies. The median of the pathogenicity indices, the number of lesions and the rate of bacteria reisolation were significantly different (p<0.05) among the origins of the isolates (p<0.05). The pathogenicity index developed in this study allows the classification of Pasteurella multocida pathogenicity and may be an alternative to the pathogenicity models currently used for screening.
Abstract in English:ABSTRACT The effects of the Kluyveromyces marxianus M3 strain, isolated from Tibetan mushrooms, on plasma lipids, egg cholesterol level, egg quality, and intestinal health of laying hens were evaluated. In total, 160 Beijing fatty laying hens (43 weeks old) were divided into four groups and fed a basal diet supplemented with 0%, 0.1%, 0.3%, or 0.5% freeze-dried K. marxianus M3 powder for four weeks. The results showed that yeast supplementation reduced serum total cholesterol (TC), triglyceride (TG), low density lipoprotein-cholesterol (LDL-C), and very low density lipoprotein-cholesterol (VLDL-C) levels (p<0.01), and increased serum high density lipoprotein-cholesterol (HDL-C) level (p<0.05). Moreover, regardless of K. marxianus M3 dietary addition level, the cholesterol content of the eggs decreased by more than 26%. When0.3% yeast was supplemented, significant differences were found in the egg weights, shell strength, albumen height, Haugh unit and nutrient content of the eggs (p<0.01). Finally, 0.3% yeast supplementation improved the intestinal flora conditions of the hens by decreasing the Salmonella and Staphylococcus aureus counts (p<0.01) and increasing the Bifidobacterium count (p<0.01). The results in this work demonstrated that yeast culture supplementation to the diets deceased the serum and egg yolk cholesterol, and increased egg quality.
Abstract in English:ABSTRACT The aim of this study was to determine if sex influenced abdominal fat yield, chemical composition, pH, color, fatty acid profile, and stability (by Differential Scanning Calorimetry - DSC) of Cobb chickens. Abdominal fat yields of 1.86 and 1.49% were obtained for females and males, respectively. Abdominal fat lipid contents of 70.68 and 74.36 g/100g, moisture content of 27.87 and 24.09 g/100g, protein content of 0.91 and 0.95 g/100g, ash content of 0.038 and 0.041 g/100g were obtained in males and females, respectively. Fat pH was not different between sexes, with values of 6.71 for males and 6.63 for females (p<0.05). Color L* values of 58.67 and 55.42, a* values of 4.95 and 3.44, and b* values of 7.36 and 8.18 were obtained for males and females, respectively. Female abdominal fat contained higher proportion of oleic acid (53.87%) followed by palmitic acid (30.07%), whereas 34.69% palmitic acid, 31.92% oleic acid, and 25.30% linoleic acid were determined in males. The proportions of the evaluated fatty acids were significantly different (p>0.05) between males and females, except for palmitic acid. The DSC analysis showed no significant difference (p>0.05) between sexes for melting and crystallization points. It was concluded that sex influences abdominal chicken fat yield, chemical composition, color, and DSC parameters.
Abstract in English:ABSTRACT We investigated the effect of heat stress (HS) on the expression of the GABA receptor in the hypothalamic-pituitary-gonadal (HPG) axis of Wenchang chickens. Real-time quantitative RT-PCR (qRT-PCR) was used to quantify the GABA receptor mRNA levels along the HPG axis of chickens under HS (40±0.5 °C) for 1-6 weeks. Our results showed that the expression of GABAA and GABAB receptor at the mRNAs levels in the tissues of HPG axis exhibited fluctuation and variability. After HS, the mRNA level of GABAA receptor was significantly reduced in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but significantly increased in the pituitary of 1-, 4-, and 5-week-old chickens. The GABAB receptor mRNA level significantly declined in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but was significantly upregulated in the pituitary and testis of 1- and 2-week-old chickens. At other time points, the expressions of GABAA receptor and GABAB receptor showed no significant differences compared with control group. These results indicated that the levels of GABAA receptor and GABAB receptor mRNAs varied in different tissues of the HPG axis in chickens of different ages, displaying temporal and spatial variations. GABA receptor behaved as a positively-regulated gene by HS, i.e., its mRNA was increased by HS; similarly, it was a negatively-regulated gene by HS, when its expression was reduced by HS.
Abstract in English:ABSTRACT This study aimed at evaluating the effect of the use of disinfectants and insecticides recommended for the control of pathogens and insects in poultry houses on the biological parameters of the entomopathogenic fungus Beauveria bassiana strain Unioeste 4. Disinfectants and insecticides were used at recommended concentration (RC), half the recommended concentration (0.5 RC), and twice there commended concentration (2RC). All treatments were sprayed on the fungus previously inoculated on PDA culture media. Germination, colony forming unit (CFU), vegetative growth and conidial yield were evaluated. Germination was the most affected parameter by insecticides, with reduction of up to 25% using Couro Limpo and Cypermil products. Cypermil also reduced the vegetative growth in all tested concentrations. Conidial production was reduced when products were used at the highest concentration. On the other hand, the confirmed mortality of the lesser mealworm by the fungus was not affected by none of the tested products. All disinfectants at the highest concentration reduced germination and conidia production, but did not affect fungus vegetative growth. The confirmed mortality by the fungus was most influenced by the product TH4. All tested products tested were considered compatible with the fungus.
Abstract in English:ABSTRACT The Pantanal is the world's largest wetland biome with a seasonal flood pulse that attracts a great diversity of birds, many of which are migratory. Birds can be natural reservoirs Influenza A, West Nile and Newcastle Disease viruses. However, the occurrence of carriers for these viruses in the Pantanal was not verified yet. The present study evaluated the occurrence of natural infection by Influenza A, WN and ND virus of birds in the municipality of Poconé, a subregion of the Pantanal in the state of Mato Grosso, Brazil. A total of 76 birds belonging to 11 orders and 20 families were captured using mist nets. The most representative order was Passeriformes, followed by the other nine orders, which included Columbiformes, Psittaciformes, Charadriiformes and Anseriformes. The most representative family was Thamnophilidae, with 16 individuals (21.0%), followed by the family Tyrannidae with 10 individuals (7.6%) and the family Furnariidae, with eight individuals (10.5%). The bird species were identified, and cloacal and tracheal swab samples were collected. The samples were subjected to RNA extraction and tested for the presence of the three agents by real-time polymerase chain reaction (qRT-PCR). All the sampled birds were considered healthy, had no clinical sign of infection, and were tested negative for the three viruses. Based on our findings, we can conclude that Influenza, West Nile and Newcastle Disease viruses were absent from the samples in this region of the Pantanal wetlands during the period of this study.
Abstract in English:ABSTRACT The objectives of the present study were to evaluate the water and protein contents and the water-to-protein ratio of chicken parts before and after the pre-chilling process, to compare these results with the values officially recommended by the Brazilian Ministry of Agriculture, and to evaluate the effect of genetic strain and sex on these parameters. Water (%) and protein (%) contents, and water-to-protein ratio (WPR) of boneless and skinless breast (FILLETS) and breast with bone and skin (BREAST) were determined before (BPC) and after (APC) carcass pre-chilling. A total of 585 samples were evaluated: 221 fillets/male, 216 breasts/male, 76 fillets/female, and 72 fillets/female of four different broilers strains were evaluated before (BPC) and after (APC) samples. Water and protein contents and water-to-protein ratio were determined according to the Brazilian legislation. Results showed that there were no significant differences between genetic strains (p<0.05) neither in samples collected before or after the chiller. There were no statistical differences in the parameters studied among genetic strains. However, a high percentage of male breast samples presented water level and water-to-protein ratio above the official limits already before pre-chilling.
Abstract in English:ABSTRACT The Infectious Bursal Disease (IBD) is a contagious viral disease that affects young chickens and may cause high morbidity and mortality. As the virus is very resistant to the environment, vaccination is required in case of high infection pressure. Due to variations in the virulence degree of the vaccines available to control IBD, this study aimed at evaluating the pathogenicity and immunogenicity of three types of vaccines. In total, 220 one-day-old specific pathogen free (SPF) chickens were immunized with recombinant, immune-complex and intermediate vaccines, or not vaccinated (55 birds per group) and challenged with IBD G11 strain on day 25. On days 25, 30, and 35, the Bursa of Fabricius (BF) were submitted to gross and histological examination, and serum samples were submitted to ELISA to determined anti-IBD antibody titers. On day 23, chickens were submitted to the test of hypersensitivity to phytohemagglutinin to evaluate the immunosuppressive effect of vaccines on the cell-mediated immunity. The results have indicated that the immune-complex vaccine induced the most severe BF lesions, whereas the recombinant vaccine preserved BF tissue and cell integrity. The three evaluated vaccines induced humoral immunity of similar intensity. The cellular reaction to phytohemagglutinin of the chickens immunized with recombinant and immune-complex vaccines was less severe compared with the unvaccinated chickens. In conclusion, these results indicate that the immune-complex vaccine was the most pathogenic and that all vaccines were effective in protecting SPF chickens against IBD.
Abstract in English:ABSTRACT The aim of the present study was to demonstrate the histological and histochemical structure of the Harderian gland in wild and hybrid of wild and domestic birds. The samples were stained with haematoxylin-eosin, methyl green-pyronin Y, periodic acid-Schiff, alcian blue pH 2.5, aldehyde fuchsin and Hale's dialyzed iron staining's. In both species, the glands had multilobar tubuloacinar structure type I. The Harderian gland was located in the orbit near the inter-orbital septum, between the medial rectus muscle, the pyramidal muscle of the third eyelid, and the ventral oblique muscle. In the common pheasant, the gland was wider in the proximal and distal part. The common pheasant had more elongated lobes of the Harderian gland than in the hybrid. In the common pheasant, the glandular cells presented darkly-stained serous secretion and lightly-stained mucous secretion. In the hybrid, the glandular cells presented seromucous secretion. The central lobar space, interacinar space, and apical parts of the acini of the Harderian glands were filled with many lymphocytes and plasma cells, particularly in the common pheasant, where centers of all large lobes were abundantly filled with plasma cells. The plasma cells dominated in common pheasant's Harderian gland, while in the hybrid, lymphocytes and plasma cells were present at similar quantities. The cells positive for periodic acid of Schiff staining were dominant in hybrid. Periodic acid-Schiff, Hale's dialyzed iron and alcian blue pH 2.5 stainings demonstrated acid-carboxylated mucopolysaccharides in the glandular cells cytoplasm of the examined birds.
Abstract in English:ABSTRACT The aim of this study was to determine the effect of lycopene addition to the curing mixture for steamed and grilled breast muscles on the chemical composition, sensory attributes and physicochemical parameters of the final products. The experimental material comprised a total of 48 breast muscles of Hybrid XL turkeys aged 15 weeks and fed commercial pelleted diets. The material was divided into three groups (control, experimental groups I and II). Sixteen breast muscles (8 left and 8 right) were assigned to each group. Control group samples were immediately transported to a laboratory. The remaining 32 muscles were steamed and grilled, where 16 samples were cured before heat treatment. The curing brine contained tomato peel extract standardized for 5% lycopene content. The results of the study indicate that the lycopene increased vitamin E levels and decreased the ash and vitamin A content of the final products. Lycopene also lowered the aroma and flavour scores, and increased the shear force values of the final products. The addition of lycopene lowered the pH of the products measured in a water homogenate and deteriorated the hydration properties of meat. Lycopene increased the darkness and the contribution of redness, which led to an increase in colour saturation and hue values of the evaluated samples. It can be concluded that lycopene exerted antioxidant effects and improved the colour parameters on the external surface and along the cross-section of processed meat. However, the specific flavour of tomatoes deteriorated the sensory attributes of the final products.
Abstract in English:ABSTRACT The objective of this study was to evaluate the efficiency of electrical stunning by electronarcosis in a medium-size poultry processing plant located in southern Brazil. The current measurement of this type of stunning is presented, and then improvements to this method are proposed. Data were collected for 90 days. A quality indicator was proposed: the Stunning Severity Index (SSI), which includes elements of Statistical Process Control (SPC) using a p-chart (proportion chart) and measures. This index comprises the variables "wing-flapping," "arched head," and "rhythmic breathing." Using the proposed index, 5% of the birds, on average, presented inefficient stunning symptoms.
Abstract in English:ABSTRACT The routine use of antimicrobials in animal production for the treatment of infections, disease prevention, or as growth promoters is a predisposing factor for the development and dissemination of antimicrobial resistance. In food industries, sanitizers are used for the control of microbial colonization, and their efficacy depends on contact time and on the dilution of the products used. The present study assessed the effect of 12 antimicrobials and four commercial sanitizers on 18 Salmonella spp. strains isolated from poultry processing plants. None of the evaluated antimicrobials was 100% effective against the tested Salmonella spp. strains; however, 94% of the isolates were susceptible to ciprofloxacin, 77% to amoxicillin + clavulanic acid and to ampicillin, and 72% to enrofloxacin, whereas 100% of the isolates were resistant to penicillin G, 16% to tetracycline, and 11% to sulfonamide. The tested Salmonella spp. strains were 100% inhibited by peracetic acid after five minutes of contact, 0.5% by quaternary ammonium after 15 minutes, and 85.7% by chlorhexidine after 15 minutes. The results indicate the importance of testing of efficacy of antimicrobials used in animal production and in public health to monitor their action and the development of resistance.
Abstract in English:ABSTRACT Adverse environmental conditions during rearing may negatively affect productivity and meat quality of the modern fast-growing broiler strains. Temperature manipulation during sensitive embryonic development periods may affect broilers' physiological responses to environmental conditions during rearing on commercial farms. The objective of this trial was to evaluate the effect of temperature manipulation during incubation and breeder age on the meat quality of male and female broilers submitted to heat stress during the pre-slaughter period. In this experiment, 1280 broiler chicks were distributed according to a completely randomized experimental design in a 2x2x2 factorial arrangement. Treatments consisted of two breeder ages (30 and 60 weeks), two temperature programs applied in the last four days of incubation (standard or high temperature), and sex (male and female). Birds were submitted to 32 °C for 48 hours before slaughter, on day 46.Meat quality parameters (pH, temperature, color, and weight loss) were evaluated. There was significant effect (p<0.05) of sex on meat redness (a*) and fat percentage, with females presenting higher values than males in both measurements. Males incubated at the higher temperature presented higher (p<0.05) meat weight loss by pressure than females. The thermal manipulation applied during the final stage of incubation did not affect the meat yield or meat quality of broilers submitted to heat stress.
Abstract in English:ABSTRACT This experiment was conducted to evaluate the dietary supplementation of canola meal (CM) on the growth performance, carcass characteristics, antibody titers against Newcastle disease virus and Infectious bronchitis virus, and blood profiles of broiler chickens. In total 600 day-old feather-sexed Ross male broiler chicks were randomly assigned into five treatments with six replicates of 20 birds each for 35 days. Treatments consisted of five experimental diets containing 0 (control), 3, 5, 10, or 15% canola meal (CM). Final body weight (BW) was not affected by the dietary treatments. Daily BW gain (DWG) and feed intake linearly decreased as dietary CM inclusion increased during the starter phase (p<0.0001), but not during the grower and total rearing periods. Chicks fed the diet with 15% CM presented the lowest DWG during the starter phase. Breast meat yield of CM-fed chicks linearly decreased as CM inclusion level increased (p=0.0014). Dietary CM supplementation did not influence organ relative weights, except for the spleen, meat quality, or blood profile. The results suggest that the CM may replace soybean meal (SBM) with no detrimental effects on overall growth performance or physiological responses of broiler chickens. However, it is recommended that supplementing excess amount of CM into broilers' diet should be taken into account in practical diet formulation as it could impair growth performance at early age and lower breast meat yields.