Abstract in English:Around the world, people who care for animals as stock keepers, stockmen, farmers, producers are placed in a position where they can greatly influence the quality of life of the animals they manage. This is particularly true in broiler chickens, where large numbers of animals can be cared for by comparatively small numbers of people. There is an international progression to start to assess poultry welfare on farm by looking at the animals themselves using (Animal Based Measures ABMs) rather than by looking exclusively at the resources provided (space, light heat, litter material - Resource Based Measures RBM's). In general, the areas being assessed are: Are the animals properly fed and supplied with water? Are the animals properly housed? Are the animals healthy? Can the animals express a range of behaviours and emotional states? Different types of organisations are starting to use ABM's - Government inspection bodies - for example state veterinary staff, Research institutes - wishing to use standardized assessment methods for research, Animal Welfare NGO's, Farm assurance companies and Legislators. The WelfareQualityNetwork® (WQN) http://www.welfarequality.net/everyone has described ABM's which address twelve health and welfare criteria and has tested them on a large number of farms across Europe. Some examples from this assessment scheme are described.
Abstract in English:The aim of this study was to evaluate the efficacy of turmeric (Curcuma longa), also known in Brazil as saffron, on the reduction of Staphylococcus aureus and Escherichia coli counts in chicken meat. Forty breast meat samples were divided in two groups (A and B). In group A, 10³-10(4)E. coli (ATCC 25922) cells were inoculated and group B samples were inoculated with 10(4)-10(5)S. aureus (ATCC 9801) cells, after which each group was divided in three samples. The first sample was analyzed immediately after inoculation. The second sample (control group) was stored at 4 ºC for 48 hours and turmeric at 1% (w/w) was added to the third sample, which was homogenized and then stored under the same conditions as the second sample. E. coli and S. aureus were enumerated in all samples. Mean bacterial counts determined for the control samples and for the samples with turmeric addition after 48h of storage were 1.83 x 10(4) CFU g-1 and 1.80 x 10(4) CFU g-1 for S. aureus, and 9.36 x 10³ CFU g-1 and 7.25 x 10³ CFU g-1 for E. coli, respectively. The results showed that there was no significant reduction in bacterial counts with the addition of 1% turmeric to chicken breast meat.
Abstract in English:In this study, 360 male broilers, out of which 240 of a fast-growing strain (Cobb500), and 120 of a slow-growing strain (Label Rouge), were used to evaluate the effect of dietary fiber on digesta transit time and digestive metabolism during the period of 1 to 42 days of age. A completely randomized experimental design with a 3x2 factorial arrangement was applied, consisting of three groups of birds (slow-growing - SG; fast-growing fed ad libitum - FGAL; and fast-growing pair-fed with SG broilers - FGPF) and two iso-protein diets (a 3100 kcal ME/kg low-fiber diet - LFD- and a 2800 kcal ME/kg high-fiber diet - HFD- with 14% wheat bran and 4% oat hulls). HFD-fed birds presented lower ME retention (p < 0.001) and lower dry matter metabolizability (DMM) (p < 0.001), which is possibly related to the shorter digesta transit time observed in these birds (p < 0.001). DMM was reduced with age, whereas metabolizable energy remained almost constant (p < 0.001) independently of strain. This may be related to the increase in feed intake as birds age. The slow-growing strain did not present better utilization of the high-fiber diet as compared to the fast-growing strain in none of the analyzed ages, even though showing a significant better use of fiber and dietary energy from 31 days of age.
Abstract in English:The aim of the present study was to comparatively evaluate hemogram, blood serum components and anatomopathologic alterations in commercial layers experimentally challenged with an attenuated vaccine candidate strain (SG∆cobS∆cbiA) and other two pathogenic strains (SGDcobS and SGNalr) of Gallinarum (SG). In total, 280 commercial layers were randomly divided into 4 groups (G1, G2, G3 and G4). At five days of age, birds from groups G1 received approximately 107 colony forming units (CFU) of SGDcobS; meanwhile birds from group G2 and G3 received the same dose of SGNalr and SG∆cobS∆cbiA, respectively. Birds from G4 were not infected. At 24 hours before (DBI) and 24 hours after (1 DAI), and three (3 DAI), five (5 DAI), seven (7 DAI) ten (10 DAI), and fifteen (15 DAI) days after the infection, 10 birds of each group were humanely killed and blood samples collected to hematological and serum tests. Samples of liver, spleen, thymus, bursa of Fabricius, kidney and heart were also collected for the histological examination. Birds inoculated with SGDcobS and SGNalr showed similar alterations in hemogram, blood serum components and anatomopathologic exams. On the other hand, the exams of birds inoculated with SG∆cobS∆cbiA strain were similar to those of the uninfected birds. However, changes could be noticed in levels of uric acid and cholesterol during the course of the infection of birds from G3. Decrease in levels of light IgG 3 DAI was also observed in birds from this group. Pyknosis in kidney cells was a microscopic alteration found in birds from G3. Further studies must be done to verify if these alterations will not interfere in the performance of the vaccinate birds with SG∆cobS∆cbiA strain.
Abstract in English:The objective of this study was to evaluate the effect of betaine in methionine- and choline-reduced diets fed to broilers submitted to heat stress. In total, 1,408 male broilers were randomly distributed into eight treatments, according to 2 x 4 (environment x diet) factorial arrangement, with eight replicates of 2 birds each. Birds were reared environmental chambers under controlled temperature (25-26 °C) or cyclic heat-stressing temperature (25-31 °C). The following diets were tested: positive control (PC), formulated to meet broiler nutritional requirements; negative control (NC), with reduced DL-methionine and choline chloride levels; and with two supplementation levels of natural betaine to the negative control diet (NC+NB1 and NC+NB2). Live performance, carcass traits, and intestinal morphometrics were evaluated when broilers were 45 days of age. The results showed that all evaluated parameters were influenced by the interaction between environment and diet, except for breast meat drip loss. The breakdown of the interactions showed that birds fed the PC diet and reared in the controlled environment had greater breast drip loss than those submitted to the cyclic heat-stress environment. Birds submitted to cyclic heat stress and fed the PC diet presented the lowest feed intake. Feed conversion ratio was influenced only by diet. The FCR of broilers fed the NC+NB2 diet was intermediate relative to those fed the PC and NC diets. The addition of betaine in the diet, with 11.18% digestible methionine and 24.73% total choline reductions, did not affect broiler live performance, carcass yield, or intestinal morphometrics.
Abstract in English:Tinamou (Rhynchotus rufescens) is a native bird of the Brazilian fauna and has great potential to become a domesticated species. From this perspective, the objective of this study was to evaluate the carcass and main parts yield and to assess meat quality of that bird. Two trials, one studying stocking density and the other litter materials, lasting 60 days each, were conducted. The studied traits were evaluated in two birds/replicate/treatment. Performance was evaluated by the least square method. The results showed that bird age at slaughter significantly influenced carcass and breast yields (p<0.05). Mean carcass, breast, thighs+drumstick and wing yields were 86.50±2.78%, 32.84±1.50%, 27.71±1.44%, and 13.21±0.94%, respectively. Shear force, pH, water holding capacity, lightness, redness and yellowness means and standard deviations were 1.92±0.98 kgf.cm-2, 6.07±0.12; 70±0.53%, 48.30±0.96, 1.96±1.01, and 1.61±1.0, respectively. Moisture, ash, crude protein, fat, and cholesterol contents were 72.35±0.16%, 1.12±0.06%, 25.53±0.50%, 0.17±0.01%, and 18.87±2.76 mg/10g, respectively. Results showed carcass and parts yields and the physical-chemical traits of tinamou meat are similar to chicken meat; however, tinamou meat is less acidic and has higher protein level combined with less calories and lower cholesterol levels.
Abstract in English:The Brazilian Ministry of Agriculture (MAPA) regulations establish 12 hours as the maximum pre-slaughter fasting period for broilers; however, many processing plants have considered this time is not sufficient, and consequently return the birds to the farms, with consequent economic losses and welfare problems. Therefore, it is necessary to investigate the possible effects of longer pre-slaughter fasting times. The objective of the present study was to evaluate the effect of pre-slaughter fasting times longer than those established by MAPA on broiler welfare, breast meat quality, and intestinal integrity. Forty 42-d-old broilers were submitted to different pre-slaughter fasting times: group I: 6 hours, group II 9h, group III 12h, and group IV 15h. Bird welfare was assessed before slaughter. After sacrifice, intestinal samples were collected to assess their morphology and morphometrics, and the Pectoralis major muscle was analyzed for pH and color. There was no influence (p>0.05) of treatments on breast muscle pH or color.There were no significant changes in intestinal morphometrics (p<0.05). Bird behavior was affected (p<0.05), suggesting that welfare was impaired as fasting time increased, but no differences in the analyzed parameters were detected between broilers fasted for 12 or 15 hours. It was concluded that the behavioral differences between birds fasted for 12 and 15 hours are not sufficient to assert that those fasted for 15 hours were in worse welfare conditions.
Abstract in English:Two experiments were carried out to compare two techniques (amino acid supplementation and dilution) for formulating experimental diets for pre-starter (1 to 8 days) and starter (8 to 22 days) broiler chicks and to estimate digestible lysine requirements using the dose-response method. In each experiment, 1,200 male Cobb 500 chickens were randomly distributed according to a 5x2 factorial arrangement (lysine level x formulation technique) with six replicates of 20 birds each. For the supplemented diet, a basal diet was formulated to meet the nutritional requirements, then L-lysine HCl was added to achieve digestible lysine levels of 0.975, 1.082, 1.189, 1.296 and 1.403% in the pre-starter diets and 0.840, 0.932, 1.024, 1.116 and 1.208% in the starter diets. For the diluted diet, a diet high in crude protein (CP) and relatively low in lysine was formulated and to which was added a protein-free diet until lysine levels were similar to those described above for the supplemented diet. The results suggest that the dilution technique favored the performance potential and better met lysine requirements compared with the supplementation technique. Lysine levels required for optimal feed conversion ratio of broilers during the pre-starter and starter phases were estimated at 1.361 and 1.187%, which are equivalent to lysine intake of 0.340 and 0.797 g/day, respectively.
Abstract in English:Artificial lighting is one of the most powerful management tools available to commercial layer producers. Artificial light allows anticipating or delaying the beginning of lay, improving egg production, and optimizing feed efficiency. This study aimed at comparing the performance of commercial layers submitted to lighting using different LED colors or conventional incandescent lamps. The study was carried out in a layer house divided in isolated environments in order to prevent any influenced from the neighboring treatments. In total, 360 Isa Brown layers, with an initial age of 56 weeks, were used. The following light sources were used: blue LED, yellow LED, green LED, red LED, white LED, and 40W incandescent light. Birds in all treatment were submitted to a 17-h continuous lighting program, and were fed a corn and soybean meal-based diet. A completely randomized experimental design with subplots was applied, with 24 treatments (six light sources and four periods) of three replicates. Egg production (%) was significantly different (p<0.05) among treatments, with the best results obtained with red LED, white LED, and incandescent light sources. Egg weight, feed intake, and internal egg quality (albumen height, specific gravity, and Haugh units) were not influenced (p>0.05) by light source. It was concluded that the replacement of incandescent light bulbs by white and red LEDs does not cause any negative effect on the egg production of commercial layers.
Abstract in English:This experiment aimed at evaluating the effect of the dietary inclusion of caffeinated and decaffeinated coffee on the performance and internal and external egg quality of commercial layers. One hundred and twenty 25-week-old Hy-line Brown layers, with 1575 ± 91 average body weight, were distributed according to a completely randomized experimental design with three treatments (control, 1.2% caffeinated coffee, or 1.2% decaffeinated coffee) of five replicates of eight birds each. The inclusion of 1.2% caffeinated coffee was calculated to supply 6mg caffeine per kg body weight, which is considered a moderate dose. The applied treatments did not influence (p>0.05) feed intake, egg production, egg weight, egg mass, feed conversion ratio, Haugh units, yolk color or albumen and yolk percentages. The eggs of hens fed 1.2% caffeinated coffee presented lower (p<0.05) eggshell thickness and egg specific density. The eggs of layers fed 1.2% caffeinated coffee tended (p=0.0637) to present lower eggshell percentage. It was concluded that feeding caffeinated coffee to commercial layers does not affect their performance or internal egg quality; however, eggshell quality is impaired.
Abstract in English:The objective of the present study was to evaluate the effect of clinoptilolite and calcium levels on uric acid and calcium blood profile and bone quality of commercial layers. A total of 576 birds were distributed according to a completely randomized experimental design in a 3x4 factorial arrangement (calcium levels of 2.5, 3.1, or 3.7% and clinoptilolite levels of 0.0, 0.15, 0.25, or 0.50%), into 12 treatments with six replicates of eight birds per cage (experimental unit). The experimental period was 112 days. The experimental diets were based on corn and soybean meal. Results were submitted to analysis of variance and means were compared by the test of Tukey at 5% significance level using SISVAR statistical package. Blood uric acid was significantly influenced by the interaction of the evaluated factors. Clinoptilolite levels significantly increased blood calcium levels. There was no effect of dietary calcium levels on any of the evaluated characteristics. It was concluded that feeding layers with up to 0.50% clinoptilolite does not benefit blood uric acid and calcium concentrations and does not affect their bone quality. When layers at the end of the first laying cycle are fed ad libitum and present 119.50g/hen/day average feed intake, 3.1% dietary calcium promotes 3.7g/hen/day calcium intake, which is sufficient to maintain adequate calcium blood levels and bone quality.
Abstract in English:The objective of this study was to evaluate the influence of methionine sources (DL-methionine 99% powder (DLM) or methionine hydroxy analog liquid 88% (HMTBA)), arginine:lysine (Arg:Lys) ratio and sodium chloride (NaCl) content in the diet of broilers on their performance, carcass yield, serum biochemistry, duodenal mucosal morphology, and immune response. Birds were kept under high temperature conditions during the grower phase and were inoculated or not with an antigen. The use of HMTBA promoted better live performance and carcass yield than the use of DLM. Diets with 1.05 Arg:Lys ratio resulted in better live performance, higher carcass and breast meat yields, longer villi, shallower crypts, and stronger immune response when broilers were challenged than the 1.40 ratio. The dietary supplementation of 6.0 g NaCl/kg promoted better growth performance and carcass weight than 2.0 g NaCl/kg. There was no influence of the different methionine sources or NaCl concentrations on any evaluated intestinal morphology parameter or immune response, nor of any interactions between these sources of variation.
Abstract in English:An experiment was carried out to evaluate the effects of different nutritional strategies on nitrogen (N), phosphorus (P) and calcium (Ca) balance and on copper (Cu), manganese (Mn) and zinc (Zn) excretion in broilers during the periods of 1 to 21 days and 1 to 46 days of age. Four hundred male Cobb-500 broilers were used. A randomized block experimental design was applied, including five treatments with eight replicates of 10 birds each. A five-phase feeding program was adopted (1-8, 9-21, 22-33, 34-40 and 41-46 days of age). Treatments consisted of a control diet (C) with typical protein level and low amino acid supplementation; a reduced-protein diet supplemented with synthetic amino acids formulated on ideal protein concept (IP); C with phytase (C+PHY) supplementation; C with inorganic-organic mineral supplementation (C+MIN); and a diet formulated on ideal protein (IP) basis, and supplemented with phytase and organic and inorganic minerals (IP+PHY+MIN). IP and IP+PHY+MIN diets reduced nitrogen excretion in 13.6 and 13.1% respectively, and promoted the same nitrogen retention (g/bird) and retention efficiency as compared to the diet with typical crude protein level. C+PHY and IP+PHY+MIN reduced phosphorus, calcium and manganese excretion, and improved phosphorus retention. C+MIN and IP+PHY+MIN reduced manganese excretion, but did not influence copper or zinc excretion.