Iran José Oliveira da Silva

Efeito das condições ambientais no nível de ruído emitido por leitões

The objective of this study was to assess the influence of environmental variables on sound level emitted by piglets, and to quantify the sound bands using dB compared to the conditions of thermal comfort established by the literature. The experiment was carried out at a climatic chamber, where five piglets at nursery stage were housed and submitted to a variation of the ambient temperature ranging from 28oC to 38oC and relative humidity ranging from 50% to 80%. Sound level meters were installed to record sound levels, and data loggers to record temperature and relative humidity data. The level of activity was used to quantify the animals movement by means of image analysis. Correlation and regression analysis were applied in data for statistical analysis. Environmental variables have influence the sound level emitted by piglets when they are exposed to different thermal conditions. The sound levels were established in bands according to the thermal condition in which the animals are submitted. For comfort condition (20 to 23°C), sound level ranges from 70 to 75dB; for alert condition (23 to 30°C), sound level ranges from 60 to 70dB; and for thermal stress condition (above 30°C), it ranges from 55 to 60dB.

Níveis de vibração e choques em diferentes estradas durante o transporte de ovos férteis

The levels of vibration and shock due to transport can affect the quality of fertile eggs. The aim of this study was to characterize and to evaluate the influence of roads on the levels of vibration and shock in the transport of fertile eggs. The survey was conducted in the poultry integrator company in the State of Sao Paulo, by tracking shipments in three different seasons (spring, summer and autumn). An air-conditioned trunk was used, with a capacity of 592 boxes of eggs, totaling an average of 90,840 eggs. The evaluation of vibration levels (m s-2) and shocks on unpaved and asphalt roads were recorded by four accelerometers brand Hobo. For the vibration level, the experimental design was completely randomized in a 3 x 2 x 4 factorial. For the number of shocks the experimental design was completely randomized with a factorial 3 x 2. The worst levels of vibration and shock load occurred in the vertical direction. The asphalt road provided the worst conditions for the transport of eggs. The transport losses exceeded 1%, which are attributed to cracks and breakage of eggs.

Modelización de la mortalidad previo al sacrificio de pollos con modelos lineales generalizados doble - DOI:10.5039/agraria.v9i2a3178

El objetivo de este estudio fue estimar parametros y disenar modelos para predecir la mortalidad de pollos de engorde en distintas condiciones de pre abate, utilizandose de un modelo linear generalizado doble. Datos del pre abate de 13.937 pollos fueron colectados diariamente durante el ano de 2006 en un matadero comercial en Brasil. Distintos factores que tienen influencia sobre la tasa de mortalidad fueron analizados, como la media de temperatura de bulbo seco y humedad relativa del aire, tiempo de estabulacion, periodos diarios, densidad de los pollos por caja y estaciones del ano. Los datos fueron analizados utilizandose del Modelo Linear Generalizado Doble, una extension del Modelo Linear Generalizado (MLG), que proporciona un marco para el modelado de la dispersion en los modelos lineares generalizados y tambien la media. Como resultado, el modelaje linear generalizado doble demostro una alta precision para estimar la tasa de mortalidad de pollos de engorde, a traves de las interacciones entre los principales factores que influyen en las operaciones antes del abate de los animales.

Evaluation of the thermal efficiency of materials used as roofing systems in poultry houses.

The objective was to evaluate the reduction of radiant thermal load (RTL) and in characteristics related to thermal comfort provided by different combinations of tiles and commercial linings, through reduced and distorted scale models. This aimed to evaluate the efficiency of lining as an element to attenuate solar radiation two types of tiles (ceramic and fibrous cement) were studied associated with three different liners (linings A and B and thermal reflective C). The liners A and B, were installed under the inside part of the roof in the scale models and the thermal reflective blanket C was placed over the installation in order to simulate the thermal comfort provided by the roof shading. Meteorological variables were recorded, to the subsequent calculation of thermal comfort environmental indexes (enthalpy, black globe temperature and humidity index GTHI and radiant thermal load). Variations on the surface temperature of tiles and liners were also recorded to identify the spatial variation of temperature at different times of the day. The results showed a statistical difference between the materials used for roofing and lining. Liner B presented the highest reductions of RTL and GTHI values. The thermal mapping of the surface temperature of tiles showed that the lowest temperature were found in fibrous cement roofs white painted, while the highest surface temperatures were found in the unpainted ceramic tiles. The use of roof shading in reduced and distorted scale models did not improve the thermal conditions of the evaluated environment.

Evaluation of the Arboreal Shades Quality in Pasture

Tree shade is the main element of the thermal comfort for grazing animals. The definition of the quality shadows is an important factor for rural producer decision making. The current experiment evaluated the thermal quality of some arboreal species using climatic data and animal thermal comfort indexes. The species studied were: Pera glabrata Baill (Sapateiro), Copaifera langsdorffii Desf (Copaiba), Platycyamus regnellii Benth. (Pau Pereira), Anadenanthera mocrocarpa Brenan (Angico), and Enterolobium contortissiliquum Morong (Orelha de Porco). They were recorded and analyzed at 12:00 PM, 2:00 PM, and 4:00 PM. The registered climate data were dry-bulb temperature, wet-bulb temperature, wind speed, relative humidity, black globe temperature, light intensity, and thermal comfort indexes, such as BGHI and RTL, during the seasons of year. The randomized blocks design was used for statistical analysis with Tukey’s multiple comparison tests (1%). The arboreal species that provided the best thermal quality of shadow, with a higher reduction on the thermal heat load were the following: Anadenanthera mocrocarpa Brenan, Platycyamus regnellii Benth, Copaifera langsdorffii Desf, Enterolobium contortissiliquum Morong and Pera glabrata Baill. The phenotypic characteristics to each studied species had a fundamental influence on the shadow quality.

Geostatistical techniques of comparing swine noise levels from an automated acquisition system.

With the evolution of research related with animal welfare and thermal comfort, studies comparing the animal response of the animal by a noise or vocalization, when exposed to intensive production environments are still scarce in the academic field. The methodologies described in the literature do not provide sufficient details that can be used in further studies of noise levels of animals in confined environments. Due to the lack of information from studies related to animal bioacoustics, the aim of this work was to analyze comparatively two methodologies for automatic collection of noise levels emitted by pigs in the nursery phase. The experiment was conducted in a 4.10 m wide and 9.8 m long nursery room, where a smooth wire mesh was installed dividing the carport in ten quarters identical to the installation of decibelimeters in the geometric centre of each quadrant. Daily data of noise, temperature and humidity inside the room during the winter of 2007 were collected. Two provisions of decibelimeters were tested: 1st – Data collection with 10 sets of equipment filling all the installed quarters, and 2nd - Data collection with 5 sets of equipment arranged in “zigzag” form. The purpose was to compare what is most ideal for the collection of noise emitted by pigs, using geostatistical analysis to verify the existence of the spatial dependence among the collected points inside the room. It can be concluded by the joint descriptive analysis and kriging survey of the data that configuration 2, with 5 decibelimeters in zigzag form, was enough to feed the model prediction data for the entire room where animals were confined.

Geostatistics and Kriging Techniques for Welfare Analysis of Chickens through Enthalpy Distribution in State of São Paulo, Brazil

The current scenario shows a great challenge for animal farm production due to climate changes and their direct impact on quality and productivity levels. It is necessary to study about information standards of thermal comfort situations for animals, for this to be better understood by producers. The locations of rural buildings can be an evidence of the needs for an adequate choice of construction material or efficient cooling system. Researchers of rural buildings and ambient area use environmental physical parameters to characterize the situations to which animals are subjected. One of these parameters is enthalpy, which measures the amount of energy in a system, related with latent and sensible heat. This information allows microclimate thermal analysis of animal production systems. Thus, the present work aimed to assess geostatistical techniques concerning temperature and relative humidity and to calculate the enthalpy in 25 points of the State of Sao Paulo, Brazil, at meteorological stations in summer season. The points were used with ordinary kriging to establish a contiguous map listing all other prediction points through the chosen model. The results show on the maps regions of stress and comfort situations for poultry production between the first until the 6th week, with the areas of higher and lower risk for this production system. Thus, during the period of assessment, it was possible verify kriging maps related with the situation presented greater thermal comfort, suggesting special attention about the adoption of efficient management for poultry production.

Poultry Production Losses and their Relationship with Lairage Time Effects: A Thermodynamic Study under Tropical Conditions

The current challenges of poultry production are summarized in the reduction of losses during the production process. This stage requires a study of critical control points, especially on the pre-slaughter operations. Among these operations, few researches recommend ideal intervals of time, especially in warm and wet regions. Thus, the aim of this study was to compare different intervals of lairage time with environmental temperature influence on mortality rates. This trial was conducted in a commercial abattoir in the State of Sao Paulo, Brazil, in the year of 2006. The historical data set from more than 13,000 trucks, about broiler mortality during pre-slaughter operations, was given by the abattoir. Factors that influence the welfare of the birds were collected, such as the lairage time in abattoir and hourly dry-bulb temperature. Statistical analysis was performed using the Double Generalized Linear Models. The results showed that at highest temperatures (above 22 oC), an increase in the lairage time reduced the mortality rates, being more pronounced in the critical (25 – 28 °C) and lethal intervals (above 29 °C). In relation to lairage time, the reduction in mortality rates was more pronounced in the intervals up to 1 hour of waiting. Therefore, the lairage time recommended for broilers during heat stress conditions is over 1 hour, and the greater intervals are more desirable for poultry welfare subjected to pre-slaughter operations.

Production losses on poultry pre-slaughter operations in relation to density per cage: a daily period effects study.

Advances in world poultry production in recent years have driven discussion about the critical points during the productive process that increase losses, with emphasis on poultry mortality. Although research has been conducted towards the raising environment, a lack of studies exists on the pre-slaughter operations, which are the largest sources of losses before arrival at a slaughter plant. Thus, the present study aims to evaluate the effect of the number of birds per cage on the mortality rates, considering time of day. This trial was conducted in a commercial abattoir in the State of Sao Paulo, Brazil, in 2006. The historical data set from more than 13,000 trucks, about broilers mortality during pre-slaughter operations, was achieved through the abattoir. Factors that influence the welfare of the birds were collected, such as the daily thermal condition and the number of birds per cage. Statistical analysis was performed using the Double Generalized Linear Models. As results, there was a sharp reduction in mortality during the night with 7 birds per cage, from which the increase was mild. This similar behavior was recorded during the afternoon, with the lowest mortality associated with the density of 7 birds. During the morning, the increase in mortality occurred up to 5 birds per cage, up to the peak of 9 birds. Therefore, these results suggested an adoption of approximately 7 birds per cage, mainly in the afternoon and night, to reduce the mortality rates.