Adjust of regression models to estimate the rectal temperature of broilers for the first 14 days of life

The broiler rectal temperature (t rectal) is one of the most important physiological responses to classify the animal thermal comfort. Therefore, the aim of this study was to adjust regression models in order to predict the rectal temperature (t rectal) of broiler chickens under different thermal conditions based on age (A) and a meteorological variable (air temperature - t air) or a thermal comfort index (temperature and humidity index -THI or black globe humidity index - BGHI) or a physical quantity enthalpy (H). In addition, through the inversion of these models and the expected t rectal intervals for each age, the comfort limits of t air, THI, BGHI and H for the chicks in the heating phase were determined, aiding in the validation of the equations and the preliminary limits for H. The experimental data used to adjust the mathematical models were collected in two commercial poultry farms, with Cobb chicks, from 1 to 14 days of age. It was possible to predict the t rectal of conditions from the expected t rectal and determine the lower and superior comfort thresholds of broilers satisfactorily by applying the four models adjusted; as well as to invert the models for prediction of the environmental H for the chicks first 14 days of life.

Recycling of nutrients with application of organic waste in degraded pasture

The utilization of organic wastes represents an alternative to recover degraded pasture. The experiment aimed to assess the changes caused by the provision of different organic waste (poultry litter, turkey litter and pig manure) in a medium-textured Oxisol in Brazilian Savanna under degraded pasture. It was applied different doses of waste compared to the use of mineral fertilizers and organic mineral and evaluated the effect on soil parameters (pH, organic matter, phosphorus and potassium) and leaf of Brachiariadecumbens (crude protein, phosphorus and dry mass production). It was observed that application of organic waste did not increase the level of soil organic matter and pH in the surface layer, and the application of turkey litter caused acidification at depths of 0.20-0.40 m and 0.40-0.60 m. There was an increase in P and K in the soil with the application of poultry litter and swine manure. All organic wastes increased the productivity of dry matter and crude protein and phosphorus. The recycling of nutrients via the application of organic waste allows efficiency of most parameters similar to those observed with the use of mineral sources, contributing to improving the nutritional status of soil-plantsystem.

Using data mining to identify factors that influence the degree of leg injuries in broilers

Locomotor problems prevent the bird to move freely, jeopardizing the welfare and productivity, besides generating injuries on the legs of chickens. The objective of this study was to evaluate the influence of age, use of vitamin D, the asymmetry of limbs and gait score, the degree of leg injuries in broilers, using data mining. The analysis was performed on a data set obtained from a field experiment in which it was used two groups of birds with 30 birds each, a control group and one treated with vitamin D. It was evaluated the gait score, the asymmetry between the right and left toes, and the degree of leg injuries. The Weka ® software was used in data mining. In particular, C4.5 algorithm (also known as J48 in Weka environment) was used for the generation of a decision tree. The results showed that age is the factor that most influences the degree of leg injuries and that the data from assessments of gait score were not reliable to estimate leg weakness in broilers.

Thermal comfort in reduced models of broilers' houses, under different types of roofing materials

The research was developed to evaluate the use of different types of roofing materials regularly used in poultry houses. Measurements of thermal comfort were made through the use of techniques such as the Black Globe and Humidity Index (BGHI), the Thermal Heat Load (THL) and Enthalpy (H). Conducted in the State University of Goiás, during the months of April and May, 2011, the experiment was composed of five different treatments: AC - Asbestos cement tiles, BA -Bamboo tiles, BAP - Bamboo tiles painted in white, FB -Vegetable fiber tiles and bitumen, FBP -Vegetable fiber tiles and bitumen painted in white. The experiment consisted in 15 repetitions, which were considered the different days of measurements taken. Throughout the studied period, the time of the day considered the least comfortable was the one observed at 2:00pm, and the coverage of vegetable fiber and bitumen showed the highest value of BGHI (84.1) when compared to other types of coverage, characterizing a situation of lower thermal comfort, and no difference was found for THL and H on treatments in the studied region.

Evaluation of the heating of broilers in shed by means of gas hoods and underfloor heating

This study was conducted to evaluate and compare the behavior of the heating inside poultry shed through gas hood and underfloor heating. The experiment was conducted in poultry shed belonging to the Federal Institute of Education, Science and Technology of Triângulo Mineiro Region, Uberlândia city – state of Minas Gerais (MG), Brazil. The dimensions of the shed are 24 meters long and 9.6 meters wide and with a ceiling height of 3.2 meters. The temperature was measured with an optical thermometer of Minipa brand, MT 350 model. It was used, to the analysis of temperature behavior, the public domain software FEMM 4.2, which uses finite elements techniques, with data collected from two lots. Underfloor heating is made using hot water flowing through a serpentine type system, which is installed below the bed; this hot water is from solar heaters. An energetic and economic assessment of the warming shed for raising chickens was realized. From the results obtained with the simulations, it may observe that the heating through the floor provides a more homogeneous distribution of temperature when compared with the hood heating. The flow of heat is upwards supplying, thus, the greatest need of heating of the bird, which is the pectoral part.

Transport of broilers: load microclimate during Brazilian summer

The objective of this study was to characterize the microclimatic profile of broiler transport trucks under commercial conditions, in the summer, by continuous monitoring of environmental variables (temperature and air relative humidity). Three loads were monitored from farm to slaughterhouse, considering factors such as distance and day periods (morning, afternoon, and night). To obtain the profile of the environmental variables during journey, data loggers, that determined the microclimate to which birds were submitted, were installed in the trucks; data loggers also allowed visualization of the Enthalpy Comfort Index (ECI) so that load regions could be classified according to heat comfort limits for 6-week old poultries. Temperature, relative humidity, and ECI in the truck were analyzed, using geostatistics, by the ordinary kriging method. The afternoon was the most critical period, and truck central and rear regions were most problematic for chickens, thus most susceptible to losses.

Light emitting diode (LED) use in artificial lighting for broiler chicken production

Light emitting diode (LED) has been used in commercial poultry industry by presenting superior energy savings and providing feasibility on production process. The objective of this research was to evaluate performance and carcass yield of broiler chickens exposed to different LED colors compared with fluorescent lamps. For that, two experiments (E1 and E2) were performed and 2,646 Cobb® chickens were used. In experiment E1, male birds were exposed to 20 lux artificial lighting with red, yellow, blue, and white LED bulbs; and fluorescent bulb. In experiment E2, male and female birds were exposed to 15 lux artificial lighting with red and blue LED bulbs; and fluorescent bulb. Cumulative weight gain (kg), feed intake (kg), feed conversion, hot carcass weight (kg), carcass yield (%), and breast and thigh + drumstick yield (%) were used as response variables. Results showed no difference (p > 0.05) among treatments for performance, carcass yield, and cut yield in experiment E1. In experiment E2 there was only difference between genders (p < 0.05) and males showed higher total weight gain, feed intake, hot carcass weight and thigh + drumstick yield. Different LED color use had same effect as fluorescent lights on broiler performance and carcass yield.

Impact of different light sources on broiler rearing environment

Broiler production is highly dependent on the use of artificial light. The light source may affect the effectiveness of housing conditions due to increasing ambient temperature and concentration of noxious gases. This research aimed to evaluate the effects of different bulb types on the thermal, aerial, and acoustic environment of broiler aviaries. The experiment was carried out at a commercial broiler farm in Dourados, Mato Grosso do Sul State, Brazil. Three aviaries were used, and two flocks of male broilers from Cobb® genetic strain were reared from the first day to slaughter. Each aviary was equipped with a different light source, comprising the adopted treatments (A1 - incandescent light bulb, control; A2 - sodium vapor light bulb; A3 - fluorescent light bulb). The aviaries were divided into nine quadrants, and the environmental data (ambient dry bulb temperature and relative humidity), litter surface temperature, CO2 and NH3 concentrations, and bird sound pressure behavior were recorded in each quadrant. The aviary with incandescent light presented higher air and litter temperatures, and concentration of gases than the other tested alternatives. It also presented higher level of sound pressure in the second week of the growing period; however, from this period up to slaughter, there was no effect of the light source on the results of broiler sound pressure level.

Integrated multivariate analysis to evaluate effects of pre-slaughter handling on pork quality

The aim of this study was to investigate the effect of pre-slaughter handling on the occurrence of PSE (Pale, Soft, and Exudative) meat in swine slaughtered at a commercial slaughterhouse located in the metropolitan region of Dourados, Mato Grosso do Sul, Brazil. Based on the database (n=1,832 carcasses), it was possible to apply the integrated multivariate analysis for the purpose of identifying, among the selected variables, those of greatest relevance to this study. Results of the Principal Component Analysis showed that the first five components explained 89.28% of total variance. In the Factor Analysis, the first factor represented the thermal stress and fatiguing conditions for swine during pre-slaughter handling. In general, this study indicated the importance of the pre-slaughter handling stages, evidencing those of greatest stress and threat to animal welfare and pork quality, which are transport time, resting period, lairage time before unloading, unloading time, and ambience.

Sanitary quality of broiler litter reused

ABSTRACT Considering the importance of the substrate to bedding in the poultry industry in Brazil, and the enormous pressure on environmental management as to the correct use and management of the waste generated by the production sector, this study aimed to analyze the effect of reuses of two types of litter on sanitary qualities and productive performance of broilers. The study was conducted with litter from 32 different broiler houses, two types of substrates and four cycles of reuses. The litter sanitary quality was verified by the identification of the presence of Escherichia coli and Salmonellaspp. and the incidence of footpad dermatitis. It was observed that the coffee hulls litter presented a reduction of 28.61 percentage points in the probability of occurrence of Salmonella spp when compared to the wood shavings litter, nevertheless, no statistical difference was observed on bacterial occurrence with Salmonella spp. for litter of different types or numbers of reutilization. The presence of Escherichia coli was detected in litter of all cycles, for both types of substrate. The occurrence of footpad lesions was detected for both types of litter, and was influenced by the number of reutilization cycles of the litter. The degree of incidence was detected only for the litter with coffee hull in which there was an increase of 30% between the first and second reuse from which tended to stabilize.

Fuzzy modeling of broiler performance, raised from 1 to 21 days, subject to heat stress

ABSTRACT Given the need to obtain systems to better control broiler production environment, we performed an experiment with broilers from 1 to 21 days, which were submitted to different intensities and air temperature durations in conditioned wind tunnels and the results were used for validation of afuzzy model. The model was developed using as input variables: duration of heat stress (days), dry bulb air temperature (°C) and as output variable: feed intake (g) weight gain (g) and feed conversion (g.g-1). The inference method used was Mamdani, 20 rules have been prepared and the defuzzification technique used was the Center of Gravity. A satisfactory efficiency in determining productive responses is evidenced in the results obtained in the model simulation, when compared with the experimental data, where R2 values ​​calculated for feed intake, weight gain and feed conversion were 0.998, 0.981 and 0.980, respectively.

The use of infrared thermography in the identification of pododermatitis in broilers

ABSTRACT International trade in broiler’ feet, mainly to Asian markets, has demanded better quality control. The objective of this research was to study the suitability of using chicken footpad surface temperature to determine early lesions of pododermatitis. The project was conducted in two houses A1 and A2) in a commercial farm during one production flock. A1 had reused litter of wood shavings and rice hulls, and A2 had a new litter of sawdust. Both houses had positive pressure ventilation. The inner area of the poultry was virtually divided into three quadrants. The footpads were checked for the feet quality, and a degree of pododermatitis was awarded. Thermal images were made to test the surface temperature of the foot and identify inflammation in a total of 30 birds per house, at ages 5, 19, 29, 28 and 40 days of grow-out. Conditions of the rearing environment as well as the surface temperature of the litter, litter moisture, and degree of compression, were recorded. The environment within the houses did not differ. The surface temperatures of the footpad did not differ between the groups. The minimum footpad surface temperatures within the scores were similar, except for the score 3, which did not occur in A1. There was a prevalence of severe injury in the house with a new litter.

Typing of avian pathogenic Escherichia coli strains by REP-PCR

In the present study the repetitive extragenic palindromic (REP) polymerase chain reaction (PCR) technique was used to establish the clonal variability of 49 avian Escherichia coli (APEC) strains isolated from different outbreak cases of septicemia (n=24), swollen head syndrome (n=14) and omphalitis (n=11). Thirty commensal strains isolated from poultry with no signs of these illnesses were used as control strains. The purified DNA of these strains produced electrophoretic profiles ranging from 0 to 15 bands with molecular sizes varying from 100 bp to 6.1 kb, allowing the grouping of the 79 strains into a dendrogram containing 49 REP-types. Although REP-PCR showed good discriminating power it was not able to group the strains either into specific pathogenic classes or to differentiate between pathogenic and non-pathogenic strains. On the contrary, we recently demonstrated that other techniques such as ERIC-PCR and isoenzyme profiles are appropriate to discriminate between commensal and APEC strains and also to group these strains into specific pathogenic classes. In conclusion, REP-PCR seems to be a technique neither efficient nor universal for APEC strains discrimination. However, the population clonal structure obtained with the use of REP-PCR must not be ignored particularly if one takes into account that the APEC pathogenic mechanisms are not completely understood yet.

Genetic grouping of avian infectious bronchitis virus isolated in Brazil based on RT-PCR/RFLP analysis of the S1 gene

Twelve Brazilian isolates and one reference vaccine strain of avian infectious bronchitis virus (IBV) were propagated in embryonating chicken eggs. The entire S1 glycoprotein gene of these viruses was analysed by reverse-transcriptase-polymerase chain reaction and restriction fragment length polymorphism (RT-PCR-RFLP), using the restriction enzymes HaeIII, XcmI and BstyI. The RFLP patterns led to the classification of these isolates into five distinct genotypes: A, B, C, D and Massachusetts. Five of twelve isolates were grouped in Massachusetts genotype and the remaining seven viruses were classified into four distinct genotypes: A (2), B (2), C (2) or D (1). Such genotyping classification agreed with previous immunological analysis for most of these viruses, highlighting the occurrence of a relevant variability among the IBV strains that are circulating in Brazilian commercial poultry flocks.

Influence of tail biting on weight gain, lesions and condemnations at slaughter of finishing pigs

The present study assessed the association of tail-biting lesions in finishing pigs with weight gain, occurrence of locomotion or respiratory disorders and abscesses during finishing period, and carcass condemnation at slaughter. The study was carried out on 4 different farms. For each animal with a tail biting lesion, two control pigs were selected. The total number of animals in the study was 312, with 104 of them being tail-bitten. Tail lesions were classified according to the degree of severity into four scores: score 0 -normal tail withou lesion; score 1-3 - increasing lesion severity, and score 4 - healed lesions. Overall, the occurrence of severe tail lesions (score 3) varied from 55 to 73% of tail-bitten pigs among farms. On all farms, healing of tail lesions was observed in 95% to 100% of the animals at the evaluation performed within 41-43 days after the commencement of the study. In two out of the four evaluated farms, pigs with score of 3 showed lower weight gain (P<0.05) compared with score 0 pigs. Before slaughter, the occurrence of locomotion problems and nodules/abscesses was associated (P<0.05) with the presence of tail-biting lesions. At slaughter, tail-biting lesions were associated (P<0.05) with the presence of abscesses, lung lesions (pleuritis and embolic pneumonia) or arthritis in carcasses. Carcass condemnation was associated with the presence of tail-biting lesions (P<0.05). Overall, carcass condemnation rate was 21.4%, of which animals with tail-biting lesions accounted for 66.7% of condemnations. Among the animals diagnosed with cannibalism at farm level, only two had not healed their lesions at slaughter. The fact that there were a lot of carcass condemnations, despite the fact that tail-bitten animals had no more active lesions, suggests that different situations may be observed between the field and slaughter, reinforcing the need to analyze pigs both at farm and slaughter to allow proper assessment of losses related to tail biting. Collectively, the observations of the present study show that complications associated with tail-biting found in slaughterhouses are probably underestimating field prevalence.