Karla Andrea Oliveira de Lima

Conforto térmico de bovinos leiteiros confinados em clima subtropical e mediterrâneo pela análise de parâmetros fisiológicos utilizando a teoria dos conjuntos fuzzy

The objective of this study was to model and evaluate, through fuzzy logic, the level of thermal comfort experienced by housed animals as a function of their physiologic variables of rectal temperature (RT) and breath rate (BR), and setting their critical thresholds. The database was setup using two distinct environments: Subtropical climate (Sao Pedro area, Brazil) and mediterranean climate (Evora area, Portugal). Holstein cows temperature and breath rates were obtained in order to build a physiologic parameters database. meteorological data of environment temperature and air relative humidity were obtained for physical analysis during a 24 hours interval every 30 minutes. Data minning techniques were used for the initial data analysis aiming to build a decision making three and the further construction of rule database. For that, the computational program WEKA® was used. The results obtained were applied for the fuzzy logic application, using the Fuzzy Logic Toolbox do MATLAB® 6.1 software, according to AMENDOLA et al. (2005b). The use of this tool allowed the establishment of thermal comfort parameters for total confined Holsteins cows.

Noise analysis to evaluate chick thermal comfort

The relationship between thermal environment and chick performance has widely been evaluated, however the consideration that the assessment of the comfort may be estimated by interpreting both amplitude and frequency of bird vocalization under tropical housing conditions is a new concept. This research had as objective of estimating thermal comfort for chicks during the heating phase using this new concept. An experiment was carried out inside a climate controlled chamber (A) for establishing the behavioral pattern related to environmental temperature limits. Forty five chicks were reared inside a 2.3 m2 box. A video camera was placed 2.0 m above the birds and the images were captured and registered in a computer. From the pattern determined in the controlled chamber an evaluation of the results was proceeded in a commercial broiler farm (experiment B) using similar bird density in order to validate the data. Environmental temperature, and both amplitude and frequency of the vocalizations of the chick group reared under heating were continuously recorded in both experiments. A correlation between group behavioral pattern and their vocalization, was found, evaluated not only by the noise amplitude but also by the noise frequency spectrum. When the thermal inertia is maintained by adequate use of curtains the birds vocalized less which is coincident with the low sudden variation of the temperature of the environmental. It was possible to estimate the thermal comfort for chicks at the heating stage by recording the amplitude and the frequency of the noise emitted by the reared group.

Impact of global warming on beef cattle production cost in Brazil

Global warming is affecting agribusiness in its economic aspects. Therefore, the prediction of the evolution of Brazilian beef cattle production cost was made using the IPCC forecast scenario for global warming. The methodology consisted of two steps: (i) the development of a fuzzy model that estimated the grazing land capacity (RP) decrease risk as a function of the changes in the average total rain index, air temperature and increase in extension of the dry season; and (ii) the design of an algorithm for predicting the decrease in production as function of the RPfuzzy model, that results in the impact in beef cattle productivity, and consequent increase in production costs. Historical environmental data from important producing counties in the Cerrado were organized and a set of fuzzy Gaussian functions were developed, and three possible settings (optimistic, medium and pessimistic) were considered. The decrease in beef cattle productivity was estimated using the losses in production due to the increase in air temperature and vulnerability of pasture capacity. The boundary settings for the total increase of production cost scenario used the number of animals per area of grazing land, the adoption of grain supplement and its future scenario; and the result output function pointed to a threshold within a variation from an increase in production cost of 80% (optimistic) to 160% (pessimistic). Under the optimistic scenario the total cost of Brazilian beef cattle production in the Cerrado became near to US

Strategies and facilities in order to improve animal welfare

2.88 kg-1, while in the pessimistic scenario this cost reached US

Assessing locomotion deficiency in broiler chicken

4.16 kg-1, challenging the international competitiveness of this economic segment.

Efeito da utilização de sistemas de climatização nos parâmetros fisiológicos do gado leiteiro

To keep the position in being a world-wide exporter of chicken meat, Brazil must meet international quality standards, always seeking alternative resources of improvement, without increasing production costs, including litter quality, requirements of animal welfare and environment affairs, such as the use and reuse of broiler litter. Researches are performed in the areas of animal welfare, environment, animal behavior and use of modern climatization technology improving the quality of the environment created to raise broilers, also trying to reduce the greenhouse gas emissions and global warming in the environment, becoming a sustainable production system. This paper has a bibliographic revision of the subject mentioned above, intending to show a state-of-art key factors related to a new concept of broiler environment and welfare.Para manter a posicao de maior exportador de carne de frango, o Brasil deve se adequar as exigencias internacionais dos padroes de qualidade, procurando sempre recursos alternativos de melhoria, sem grande incremento no custo de producao, incluindo a qualidade da cama, requisitos de bem-estar animal e as questoes ambientais, como o uso e a reutilizacao das camas de frango. Para isso sao necessarias pesquisas nas areas de bem-estar animal, ambiencia, comportamento animal e uso de tecnologias de climatizacao modernas que aperfeicoem a qualidade do ambiente gerado para criacao dos frangos, visando, alem deste fator, menor emissao de gases com potencial efeito estufa para o ambiente, tornando-se um sistema de producao sustentavel. De acordo com o exposto, realizou-se uma ampla revisao bibliografica deste assunto, buscando mostrar o estado da arte dos principais fatores relacionados aos novos conceitos de ambiencia e bem-estar de frangos de corte.

Ammonia emissions in tunnel-ventilated broiler houses

Locomotion deficiencies in broiler production cause poor welfare and lead to change in drinking and feeding behavior with consequent loss in weight gain. This research aimed to assess locomotion deficiencies in broiler chicken by analyzing the vertical peak force on both feet during walk. A chamber was built with an inlet ramp, a horizontal walkway in the middle and an outlet ramp. In the walkway a thin mat with piezoelectric crystal sensors was placed to record the step vertical peak force of the feet while walking on the force platform. The measurement system consisted of a mat with electronic sensors and software that allowed real time recording of the forces and the processing and analysis of data. Footage was taken from two digital video cameras and used for gait scoring. Forty male broilers were chosen at random, grown under similar rearing conditions and farms, with age varying from 49 to 28 days (ten birds of same age) to be used in the trial. Measurement consisted of inducing the bird to walk on the force platform which automatically registered the peak vertical force of the steps. Results showed that the gait score increased with the weight and age of the birds. Peak force asymmetry was found for each foot, independent of age or gait score. Although not identified visually in the broilers, the peak vertical force values differed in both right and left feet leading to slow and uneven walking. Walking deficiency was more severe in older birds.

Use of geostatistics on broiler production for evaluation of different minimum ventilation systems during brooding phase

This research evaluated the thermal efficiency of two evaporative cooling systems, sprinkler and misting, associated with forced ventilation, on the dairy cows thermal stress relief. The study was carried out in a commercial dairy cattle farm located in Sao Pedro city, state of Sao Paulo, Brazil. The duration of the experiment was twenty-eight consecutive days of November 2003, and 10 Holstein cows lodged in a freestall barn were studied. The relative humidity, the dry bulb temperature and black globe temperature were registered every 15 minutes, during all experimental period. Among these cows, five were selected for collecting physiological data (respiratory frequency, rectal temperature and temperature in white and black surfaces) at 9:00 a.m., 11:00 a.m., 1:00 p.m., 3:00 p.m. and 5:00 p.m., during nine non-consecutive days. According to the results, it was concluded that both of the cooling systems studied did not cause any significant differences on the rectal temperature, respiratory frequency and temperature in black surface. However, the temperature in white surface was significantly lower in the sprinkling system, at the time of 11 a.m. and 1 p.m. The misting system reduced significantly the wet bulb temperature, black globe temperature and humidity index, when compared to the sprinkling system. Both cooling systems reduced the maximum wet bulb temperature of the barn compared to the external environment.

Impact of global warming on Brazilian beef production.

Gas production in broiler houses and their emissions are closely related to the microclimate established inside the house according to air temperature, humidity, and velocity. Therefore, the internal house environment is influenced by building typology and ventilation system. The objective of the present study was to evaluate ammonia emission rates in broiler houses equipped with different ventilation systems (negative or positive pressure) and litter conditions (new or built-up). The environment of six commercial broiler houses was evaluated internal and external NH 3 concentrations. Ventilation rates were recorded to estimate ammonia emission rates. The efficiency of circulation and exhaust fans was assessed, and higher ventilation rates were determined in negative-pressure houses due to the higher flow of the fans. Houses with new litter increased ammonia emission rates along the rearing period, indicating the relationship between gas emissions, bird age and ventilation rates, and presented a typical curve of NH 3 emission increase. Negative-pressure houses with built-up litter presented higher emission rates during the first rearing week due to the high NH 3 concentration during the brooding period, when the ventilation rates required to maintain chick thermal comfort are low. Although the results of the present study indicate an advantage of the positive-pressure systems as to gas emissions, further research is needed reduce gas emissions in broiler houses with negative-pressure systems.

Impact of different light sources on broiler rearing environment

The objective of this research was to evaluate different minimum ventilation systems, in relation to air quality and thermal comfort using geostatistics in brooding phase. The minimum ventilation systems were: Blue House I: exhaust fans + curtain management (end of the building); Blue House II: exhaust fans + side curtain management; and Dark House: exhaust fans + flag. The climate variables evaluated were: dry bulb temperature, relative humidity, air velocity, carbon dioxide and ammonia concentration, during winter time, at 9 a.m., in 80 equidistant points in brooding area. Data were evaluated by geostatistic technique. The results indicate that Wider broiler houses (above 15.0 m width) present the greatest ammonia and humidity concentration. Blue House II present the best results in relation to air quality. However, none of the studied broiler houses present an ideal thermal comfort.