ABSTRACT The present study aimed to apply the Simulated Annealing (SA) optimization algorithm to find the ideal control of broiler housing rearing environment at 21, 28, 35, and 42 days of growth. Data from four types of houses using environmental control and similar flock density were recorded weekly in the morning and afternoon, during two seasons (summer and winter). The variables related to environmental and air quality data (temperature, relative humidity, air velocity, ammonia, and carbon dioxide concentrations) were registered and organized into the database to provide a descriptive analysis. The ideal rearing conditions were established as a goal, and we used the Simulated Annealing optimization algorithm to process the data. Such an approach may be applied in the cases that the ideal condition of optimization has multiple objectives, and when each variable is the result of a process. The model was implemented considering the optimal controlled environmental condition that depends on the age of broilers. Results indicated that there was a large dispersion of the data collected from the environmental variables. The process suggested that the optimized functions lead to absolute values obtained by the algorithm for each of the environmental factors of the controlled environmental system, representing the optimal condition of the environment found for each broiler age, considering the interactions of the variables. The maximum optimization was prominent to 21 and 35-d old birds, representing 40-48% of the improvement of the process. 28 and 42-d old birds might benefit from the controlled environmental optimization process by up to 30%.

ABSTRACT Trade liberalization during the last decades has increased among nations as a result of decreased tariffs. However, during the same period, market agents have created new protection measures to replace such mechanisms in an attempt to promote the domestic economic stability of countries, while expanding and ensuring the trade between nations. Considering that Brazil is the second largest broiler producer and chicken-meat exporter worldwide, the present study proposed to analyze the main barriers imposed on Brazilian chicken meat imports by the ten major importing countries. This is a documentary research with primary and secondary data, of a descriptive-exploratory nature, under a qualitative approach. Semi-structured questionnaires including open- and close-ended questions were sent using Survey Monkey software to the Brazilian Association of Animal Protein. The study revealed that technical requirements are those most often imposed by the importing countries, indicating their concern about the safety, quality, and origin of the imported good. Commercial requirements do not constitute a problem for the growth of Brazilian chicken meat exports; however, the requirements made by some countries preclude the exports.

ABSTRACT Brazilian processing plants have identified the so-calledspaghetti breast myopathy characterized by muscular dystrophy of unknown etiology. This study aimed at estimating the incidence of spaghetti breast myopathyin broilers from three commercial genetic strains (Ross, Cobb, Hubbard) reared in two different housing systems (DH, Dark house, and TS, Tunnel system), presenting different controlled ventilation systems and light availability. Breast meat samples (n=5,580) were collected and macroscopically evaluated for spaghetti breast myopathy according to a 0-2 scale, as 0 = normal, 1 = intermediate or moderate, and 2 = severe. A higher number of broilers reared in DH presented normal breasts and moderate myopathy relative to TS-reared birds. Ross broilers presented a higher incidence of normal breasts compared with Cobb and Hubbard broilers. The risk of presenting spaghetti breast myopathy was higher in broilers reared in DH than those in reared in TS, indicating that the exposure to DH environmental conditions may increase the chance of myopathy incidence. Broilers reared in dark houses presented 26% higher chance and 13% higher risk of showing spaghetti-breast myopathy the than those reared in tunnel-ventilated systems.

ABSTRACT The meta-analysis data were obtained from a survey of published articles over 15 years. The data were selected to classify the factors that impact broiler production and separated by influence aspects of animal production (thermal environment and other factors). The relevant data for each study were systematized, grouped and later tabulated and inserted into a database prepared in a spreadsheet. The variables used to analyze the thermal environment were temperature (comfort, high and low) and performance data (weight gain, feed intake, and feed conversion). The variables used for other features were ventilation (TER = tunnel + evaporative cooling, PP = positive pressure, NV = natural ventilation) and performance (feed conversion, live weight, mortality, and weight gain). The factors that may influence the production of broilers were tested by covariance analysis, Pearson correlation coefficient and divergence analysis, about the Cobb®, Ross® and Hubbard® strains. The results showed that the factors that most influenced the performance of broilers were temperature, ventilation rate, and genetic strain.

ABSTRACT Intensive broiler production requires large flock density, which compromises litter quality and increases the prevalence of footpad lesions. The present study aimed at comparing the incidence of footpad dermatitis of broilers reared in two different rearing environments. Data from two broiler houses were recorded during 42 d. Air temperature and relative humidity; litter moisture, pH, and temperature; footpad surface temperature; and the incidence of footpad lesions was investigated. Litter quality was analyzed in a 2 x 4 factorial arrangement, with two house types (dark house or open-sided house) and four rearing phases (21, 28, 35, and 42 d of growth), with four replicates per treatment using 12 replicates. Four replicates were used for analyzing the air environment data. For the footpad lesion identification, a randomly factorial scheme of recording the surface temperature was built (2 x 2) using two houses, and the broiler sex using 15 replicates in the grow-out stages. The measures of association (odds ratio and risk ratio) were calculated. The multi-criteria analysis (Analytic Hierarchy Process - AHP) was applied for estimating the house that provided less prevalence of lesions. The field data did not provide enough evidence for selection of a particular house with less incidence of footpad dermatitis. However, when applying the measures of association data, and corresponding literature data to the AHP, there was an indication that the dark-house provided broiler rearing condition that reduced the incidence of footpad lesions.

ABSTRACT The objective of the present study was to characterize the scientific production regarding the factors that influence broiler chicken production, and that were published from 2000 to 2015 in journals indexed in the database of Google Scholar, Scielo, and ScienceDirect. The research was done in the Thermal Comfort Laboratory at FEAGRI- UNICAMP, and the concept of the systematic review was applied. The research criterion was initially defined (the keywords) aiming to identify and evaluate the variables that describe the experimental characteristics and the animals. The primary keywords identified were: broiler chicken from commercial strains, broiler production, rearing conditions, thermal environment, air quality, acoustic environment, light intensity, management, and heat stress. Those were the key words searched in the database of the online libraries. The selected articles were registered into an electronic spreadsheet with the title, the name of the authors, year of publication, language, the journal where it was published, the keyword, the period when the research was done, source/ database, and the abstract. A total of 167 articles were selected, and only 34 were added to the review. The use of the systematic review of the literature allowed identifying the main variables that positively influence the broiler performance, such as the temperature near the thermal comfort, the use of roof lining, besides the use of adiabatic cooling and cast bricks in the laterals. The presence of positive ventilation, as well as the use of yellow curtains and constant lighting, has also influenced a better performance to broilers.

ABSTRACT The pre-slaughter management is one of the predisposing factors to the reduction in the quality of the carcass and broiler meat, mainly for being a stressful condition. This study evaluates the inclusion of lemongrass (Cymbopogon citratus Stapf) in the water used in the diet of pre-slaughter broilers for the first time. The carcass and meat quality parameters were evaluated. The experiment was carried out in the poultry production of an experimental sector of the Federal University of Grande Dourados - UFGD. A total of 2,594 broilers were distributed in an entirely randomized design in a factorial arrangement of 3x2x2, with three different lemongrass concentrations in the form of infusion (0. 1 and 5 g/L), two sexes and two genetic strains (Ross 308® and Cobb 500®), and with four replications. After 42 days, 144 broilers were slaughtered, and the quality parameters of carcass and meat were evaluated. A higher incidence of scratches and higher water retention capacity were found in Ross 308® male (p<0.05). Less exudate of breast fillets loss was observed in broiler Ross 308® males 72 h post-mortem (p<0.05). There was an interaction between sex and lemongrass levels in the drinking water of the broilers in the sensory analysis of meat (p<0.05), more preferably of chewiness and juiciness for males undergoing free diet for juiciness and lemongrass in the female diet with 5g/L. The use of lemongrass infusions in pre-slaughter did not bring considerable benefits to the quality of carcass and meat of broiler.

ABSTRACT The objective of this study was to determine the optimal inclusion level of liquid egg hatchery waste for the anaerobic co-digestion of dairy cattle manure. A completely randomized experimental was applied, with seven treatments (liquid hatchery waste to cattle manure ratios of0: 100, 5:95, 10:90, 15:85, 20:80, 25:75 and 30:70), with five replicates (batch digester model) each. The evaluated variables were disappearance of total solids (TS), volatile solids (VS), and neutral detergent fiber (NDF), and specific production of biogas and of methane. Maximum TS and VS disappearance of 41.3% and 49.6%, were obtained at 15.5% and 16.0% liquid hatchery waste inclusion levels. The addition of 22.3% liquid hatchery considerably reduced NDF substrate content (53.2%). Maximum specific biogas production was obtained with 17% liquid hatchery waste, with the addition of 181.7 and 229.5 L kg-1TS and VS, respectively. The highest methane production, at 120.1 and 151.8 L CH4 kg-1TS and VS, was obtained with the inclusion of 17.5 and 18.0% liquid hatchery waste, respectively. The addition of liquid hatchery waste atratios of up to 15.5%in co-digestion with cattle manure reduced solid and fiber levels in the effluent, and improved biogas and methane production.

ABSTRACT Adequate environmental temperature control is essential for incubation efficiency. Layer breeder eggs (n=360) were weighed and distributed in a completely randomized experimental design with two treatments, consisting of two incubation temperatures (T1=37.5 °C, control; and T2=39.0 °C, hot), with two incubators per temperature, and 90 eggs per incubator, totaling 360 eggs. Hatchability, embryo mortality, and chick cloacal and body surface temperatures were not affected by incubation temperature. Eggs incubated at the hot temperature presented greater egg mass loss and higher eggshell conductance than those incubated at the control temperature. Layer chicks derived from eggs incubated at control temperature showed greater absolute weight, yolk-free egg mass, and heavier hearts than those from eggs submitted to heat stress during incubation. The control group presented lower base excess and ionized calcium blood levels. Incubating eggs at temperatures higher than those recommended compromises body and heart development of layer chicks and negatively affects blood ionized calcium availability, and therefore, bone mineralization during embryo development. Efficient temperature control during the incubation of fertile eggs is essential to obtain good quality layer chicks.

ABSTRACT Embryo thermal stimulation has been studied as a means to promote epigenetic changes and to improve broiler health and performance. This study aimed at evaluating immunoglobulin (IgM, IgG, and IgA) titers, serum corticosterone levels, and organ integrity of day-old male Cobb(r) and Ross(r) broilers. Embryos were submitted to hot and cold stimuli (thermal stimulation) on days 14-18 of incubation. The thermal manipulation treatments did not affect immunoglobulin titers of 1 day-old Cobb(r) or Ross(r) chicks, and caused severe bursal lesions (scores 3 and 4) in both strains. However, serum corticosterone levels of Cobb(r) chicks were higher when embryos were submitted to hot stimulus (+1.39ºC) compared with cold stimulus (+36 ºC). Serum corticosterone levels of Ross(r) chicks were not affected by embryo temperature manipulation. The only effect of broiler breeder age was observed on IgM titers of Cobb(r) chicks, which were higher in chicks from 33-wk-old breeders. Further studies are needed to detect the optimal period of embryo thermal stimulation.

ABSTRACT Long storage periods may increase embryo mortality. The objective of this study was to evaluate the effects of storage period on the weight loss, eggshell surface temperature, hatchability, and embryonic mortality of Japanese quail eggs. Two hundred fertile eggs were collected from a flock of 30-week-old Japanese quails (Coturnix coturnix japonica). The eggs were collected for 10 consecutive days after lay, and immediately incubated. A completely randomized experimental design with 10 treatments, corresponding to the number of days eggs were stored between egg collection and setting, with 20 replicates each, was applied. Egg weight loss increased with storage period duration, starting on day 6 (2.1%, on average) and reached 3.26%, on average, in eggs stored for 10 days. The highest hatchability (p>0.05) was obtained in eggs stored for two days, which also lost the least weight (1.20%). Storage period did not influence eggshell surface temperature (p>0.05) during incubation, but higher temperatures (p<0.05) were measured on days 10 and 15 of incubation compared with day 5. Eggs stored for ten days presented the highest weight loss, and therefore, a storage period of up to five days is recommended to maintain the quality of incubated Japanese quail eggs. Furthermore, egg surface temperature increases during the second half of the incubation period as a result of increasing embryonic metabolic rate.

ABSTRACT Time of exposure and light intensity rearing house may affect the performance and egg quality of laying quails. This research aimed at evaluating the live performance, egg quality, biometry of the reproductive system, and the gastrointestinal tract of Japanese quails (Coturnix coturnix japonica) exposed to artificial light-emitting diodes (LED) of different colors in comparison with fluorescent lamps. A total of 240 Japanese quails were distributed in completely randomized experimental design with four treatments (fluorescent lamp, and green, red, or blue LED lamps) with six replicates of 10 birds each. Average egg weight and eggshell thickness were different (p<0.05) when LED bulbs were compared with fluorescent lamps. The egg weight of the birds exposed to the red LED was similar to those under a fluorescent lamp (p>0.05). The oviduct of 64-d-old hens exposed to green LED lighting was shorter (p<0.05) than those exposed to the fluorescent lamp. Red LED can be used to replace the fluorescent lamps, as they promote the same live performance, egg quality, and morphological development of the reproductive tract of laying Japanese quails.

ABSTRACT The most common lesions observed in commercial broiler farms are hock burns and pododermatitis, defined as necrotic lesions on the plantar surface of the footpads and in the hock of growing broilers, causing pain and compromising broiler welfare. The present study aimed at identifying the risks of hock burns and pododermatitis in broilers reared under commercial conditions on new or reused litter. Twenty-four 40-d-old broilers reared in two houses in a commercial broiler farm. The plantar surface of the footpads and the hocks of broiler were recorded using infrared thermal images. The incidence of hock burns in broilers reared on new litter was 0.72 times lower than those on reused litter. Broilers reared on new litter presented lower risk (0.75, RR<1) of presenting pododermatitis when compared to those reared on reused litter. When simulating the risk using a larger sample, the simulated risk of broilers presenting footpad and hock lesions when reared on new litter was 38% higher those reared on reused litter.

ABSTRACT The experiment was carried out with the objective of evaluating a methodology to estimate the angulation and equilibrium condition, relating them to gait score and the main diseases of the locomotion system in males and females of commercial broiler strains. A completely randomized experimental design in a factorial arrangement (2x2) was applied, consisting of two sexes and two genetic strains, with five replicates of 53 chickens each. The following characteristics related to broiler locomotion were studied: gait score (GS); incidence of Valgus (VAL) and Varus (VAR) deformities and of pododermatitis (POD); body angle relative the ground (ANG); equilibrium condition (EC); body weight (BW) and breast weight (BrW); and incidence of femoral degeneration (FD), tibial dyschondroplasia (TD) and spondylolisthesis (SPO). GS, and VAL and VAR were assessed inside a broiler house. Birds were then photographed to estimate ANG and EC. Birds were sacrificed at 42 days of age and analyzed for FD, TD, and SPO. Breast percentage was not influenced by sex or strain. Males showed better ANG than females, regardless of strain. Overall, the strains studied showed prostrated EC. The correlation between GS and the evaluated traits was low. There was a moderate to high association between EC and ANG both in males and females. GS showed low correlation with locomotion problems, and therefore, it is a poor indicator of skeletal diseases. On the other hand, the moderate to high correlations of ANG and EC with locomotion problems make them better indicators of bone diseases than gait score, which is possibly more related to EC and body posture than to bone pathologies.

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.