Diego Pereira Neves

Broiler surface temperature distribution of 42 day old chickens

No Brasil frangos de corte sao normalmente alojados de 1 ate 42 dias, quando sao expostos a procedimentos como: jejum, apanha, colocacao em caixas e transporte ate o abate. Manter a homeostase do corpo e de grande importância para a sobrevivencia de frangos de corte sob ambiente quente, especialmente na 7a semana de crescimento. A perda de calor varia nas partes do corpo e esta relacionada a temperatura do ar e a cobertura de penas. Avaliou-se a distribuicao da temperatura superficial usando o processamento de imagens de câmera termografica infravermelho, para caracterizar a temperatura superficial de frangos de corte de 42 dias de idade, no periodo anterior a apanha para o abate. Os frangos foram alojados de 1 a 42 dias e, antes de serem apanhados e transportados para o abate, foram registradas temperaturas superficiais infravermelho durante o dia.. Os resultados dos termogramas das regioes com penas e sem penas foram comparados, durante o 42o dia. Alta correlacao entre regioes sem penas e a temperatura ambiente foi encontrada, mostrando que estas areas respondem rapidamente a alteracoes no ambiente do alojamento. Duas funcoes foram desenvolvidas para predizer a temperatura superficial das regioes com e sem penas, do corpo de frangos com 42 dias, sendo conhecida a temperatura do ar do ambiente.

Termografia infravermelho na estimativa de conforto térmico de frangos de corte

As instalacoes avicolas devem assegurar um ambiente de conforto termico que proporcione ao animal expressar todo o seu potencial genetico para producao motivo pelo qual novas ferramentas estao sendo aplicadas para medir o conforto termico animal destacando-se as câmeras termograficas. Neste trabalho objetivou-se avaliar a associacao da temperatura superficial das aves com as das instalacoes e estimar a transferencia de calor sensivel. Para isto foram registradas as condicoes termicas de alojamento em dois aviarios com sistemas de ventilacao distintos, no periodo de marco a abril de 2011. Os aviarios foram divididos em seis quadrantes para a coleta das temperaturas superficiais obtidas atraves de uma câmera termografica infravermelho. Em cada quadrante tambem foram registradas temperatura ambiente, umidade relativa e velocidade do ar durante as coletas das imagens. Constatou-se que as temperaturas superficiais das aves estao associadas a temperatura superficial da instalacao (cortinas laterais, forro e cama). No aviario com ventilacao negativa foram registradas maiores velocidades do ar em relacao ao convencional razao pela qual possibilitou a maior transferencia de calor sensivel pelas aves, sugerindo melhores condicoes de conforto termico.

Understanding Vocalization Might Help to Assess Stressful Conditions in Piglets

Simple Summary This research aimed to analyze the possibility of assessing piglets’ welfare using the records of their vocalization. The trial was done in a pig commercial farm, and we recorded the vocal signals from piglets in several stressful exposure situations. Data mining techniques were applied to the processed signals in order to obtain a stress classification using the recorded data. We found that, using the piglets’ vocalization, it was possible to identify the most frequent stressful conditions at the farrowing phase, namely: pain, cold and hunger. Abstract Assessing pigs’ welfare is one of the most challenging subjects in intensive pig farming. Animal vocalization analysis is a noninvasive procedure and may be used as a tool for assessing animal welfare status. The objective of this research was to identify stress conditions in piglets reared in farrowing pens through their vocalization. Vocal signals were collected from 40 animals under the following situations: normal (baseline), feeling cold, in pain, and feeling hunger. A unidirectional microphone positioned about 15 cm from the animals’ mouth was used for recording the acoustic signals. The microphone was connected to a digital recorder, where the signals were digitized at the 44,100 Hz frequency. The collected sounds were edited and analyzed. The J48 decision tree algorithm available at the Weka® data mining software was used for stress classification. It was possible to categorize diverse conditions from the piglets’ vocalization during the farrowing phase (pain, cold and hunger), with an accuracy rate of 81.12%. Results indicated that vocalization might be an effective welfare indicator, and it could be applied for assessing distress from pain, cold and hunger in farrowing piglets.

The impact of evaporative cooling on the thermoregulation and sensible heat loss of sows during farrowing

Em comparacao com outras especies de animais de criacao comercial, os suinos sao mais sensiveis a temperatura ambiente elevada, pois sao incapazes de suar, e a respiracao ofegante nao e eficiente. O sistema de resfriamento evaporativo pode favorecer o conforto termico dos animais durante a exposicao a altas temperaturas e reduzir os efeitos prejudiciais do estresse termico. Objetivou-se com este estudo avaliar a troca de calor sensivel e os parâmetros de termorregulacao de porcas em lactacao submetidas a dois sistemas de climatizacao: natural e resfriamento evaporativo, durante o verao. O experimento foi conduzido em uma granja comercial com 72 porcas em lactacao, no qual foram monitoradas as variaveis ambientais (temperatura, umidade relativa do ar e velocidade do ar), os parâmetros fisiologicos das porcas (temperatura retal, temperatura superficial e frequencia respiratoria) e, assim, foi calculada a troca de calor sensivel no periodo de 21 dias de lactacao. Os resultados nao indicaram efeito significativo dos sistemas de climatizacao sobre a temperatura retal. Porem, o resfriamento evaporativo proporcionou reducao significativa na temperatura superficial e na frequencia respiratoria, alem do aumento significativo na troca de calor sensivel das porcas. A utilizacao do resfriamento evaporativo contribuiu para aumentar a perda de calor sensivel, e, portanto, este sistema pode amenizar os efeitos negativos do calor na termorregulacao das porcas lactantes durante o verao.

ESTIMATING THE MOST IMPORTANT CRITERIA FOR HATCHING EGGS AS FUNCTION OF BROILER BREEDERS AGE

This research aimed to compare two female broiler breeder ages during the incubation period regarding management using the Analytic Hierarchy Process method (AHP). This method is characterized by the possibility of analyzing a multicriteria problem and assists a decision making. This study was carried out on a commercial hatchery located in Sao Paulo, Brazil. Two ages of broiler breeder (42 and 56 weeks) were compared relative to production rate. Production index data were the same in both ages and were submitted to multicriteria decision analysis using the AHP method. The results indicate that broiler breeders of 42 weeks presented better performance than those of 56 week-old. The setter phase (incubation) is more critical than the hatcher. The AHP method was efficient for this analysis and can serve as a methodological basis for future studies to improve the hatchability of broilers eggs.

The Use of Thermal Images for Identifying Stress Condition in Piglets

One of the biggest challenges of the meat industry is the provision of animal welfare. Under stress, several physiological changes in the animal organism as increased metabolism might occur, and that can cause change in skin temperature. Thermography allows measuring the surface temperature in a noninvasive manner, without any contact with the animal. The objective of this study was to evaluate whether it is possible to identify conditions of stress in pigs from thermography. Forty piglets in nursery phase photographed separately with the infrared camera of the 880 brands tested in five different situations: normal or stress-free, hungry, cold, thirst and pain. The pictures were analyzed in the Testo ® software. We obtained the maximum temperature, minimum and average area covering most of the back of the animal. ANOVA with Tukeys test (a <0.05) were used for comparison of means, and data were processed using the Minitab ® software.

Heat Loss in Lactating Sows under Different Ventilation Systems and Diets during Summer

The experiment was conducted in a commercial farm and aimed to evaluate the heat loss and thermoregulation parameters from lactating sows under two ventilation system (natural or evaporative cooling) and two diets (natural or adjusted electrolyte balance) in the summer. Variables related to performance and thermal regulation were recorded during the 20-day lactation. Respiratory rate was recorded along with the recording of skin surface temperature and rectal temperature in the afternoon. Calculations were performed considering the heat exchange balance. Data were analyzed using Minitab 15®. Evaporative cooling led to a reduction (p<0.05) in respiratory rate, rectal temperature and skin surface temperature of the sows and increased the sow’s heat loss. However, the dietary electrolyte balance did not cause significant difference in these variables. It was concluded that the use of evaporative cooling system helped to reduce heat effects on the sows’ thermoregulation. In the diet with adequate nutritional levels for hot climates, the adjustment of the electrolyte balance did not show benefits in minimizing the effects of heat stress.

Using decision tree for classifying farrowing piglets stress conditions using vocalization.

The objective of this study was to classify different situations of stress from the vocalization of pigs in the phase of motherhood. Vocalization of 40 pigs was recorded in different stress situations in the farrowing phase (without stress, heat stress, pain, restrained from nursing) . To capture the acoustic signals unidirectional microphone was used at approximately 15 cm from the mouth of the piglets. This microphone was connected to a digital recorder, and the signals were digitized at a frequency of 44,100 Hz. Sound signals were edited and analyzed using the Praat ® software. Each collected signal was divided into three samples, and from each sample, it was extracted the maximum and minimum amplitudes, the frequency of Pith; and the frequency of formants 1, 2, 3 and 4, was obtained using that attributes within the range of amplitude (the difference of the amplitudes maximum and minimum), and duration of the signal. The algorithm J48 of Weka ® software was used for determining the stress condition. It was possible to classify four levels of stress: no-stress, pain, cold and hunger from the vocalization of pigs to the farrowing phase, with 77.95% accuracy.