Resumo

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.

Resumo

Objetivou-se com este trabalho estimar o bem-estar de suínos a partir de registros de sua vocalização, durante alojamento em granja comercial. Foram utilizados 150 suínos machos castrados, distribuídos aleatoriamente em cinco baias. Os suínos foram submetidos a diferentes situações de estresse: sede (sem acesso a água), fome (sem acesso ao alimento), estresse térmico (Índice de temperatura e umidade - ITU >74). Para o tratamento controle, os animais foram mantidos em situação de conforto, com acesso a alimento e água, e ambiente com ITU <70. Foram registrados os sinais acústicos a cada 30 minutos, durante período ininterrupto de três horas, totalizando seis coletas para cada situação de estresse. Os sinais foram digitalizados a uma frequência de até 44.100Hz, por um período de 3 minutos. Posteriormente, os áudios foram analisados pelo software Praat(r) 5.1.19. Os atributos gerados a partir desse software foram a energia do sinal (Pa²*s), amplitude máxima e amplitude mínima (Pa), a frequência de picht (Hz), a intensidade sonora (dB) e quatro níveis de formantes (F1; F2; F3 e F4), também chamados de harmônicas (Hz). Verificou-se que, dependendo do estímulo estressor e de sua duração, os atributos acústicos energia e intensidade do sinal, frequência de pitch e as formantes 2 e 4 apresentaram diferenciação. Os atributos sonoros da vocalização de suínos variam de maneira distinta em função do tipo e duração do estímulo estressante, funcionando, quando associados, como ferramenta eficiente para quantificar o grau de estresse dos animais.

This work aimed to estimate the welfare of pigs using their vocalization records during rearing in a commercial swine farm. A total of 150 barrow pigs were randomly distributed into five pens. Pigs were exposed to different stressful situations: Thirst (no access to water), hunger (no access to the food), thermal stress (Temperature and Humidity Index - THI >74). For the control treatment, the animals were kept in a situation of comfort, with full access to food and water, and environment THI <70. Acoustic signals were recorded every 30 minutes during a continuous period of three hours, totaling six samples for each stress exposure. The signals were digitized at a frequency of up to 44,100 Hz, for a period of 3 minutes. Later the audios were analyzed using the Praat (r) 5.1.19 software. The attributes generated from this software were the signal energy (Pa² * s), the maximum amplitude and the minimum amplitude (Pa), the frequency of pitch (Hz), the sound intensity (dB) and four levels of formants (F1, F2, F3 and F4), also called harmonics (Hz). It was found that depending on the acoustic attributes, the stressor stimuli and its duration indicate energy and signal strength, frequency of pitch and formants 2 and 4 showed differentiation. The sound attributes of the pig vocalization varied in different ways depending on the type and duration of the stressful exposure, functioning as an efficient tool to quantify the degree of animal degree.

Resumo

Brazil is today the world's largest broiler meat exporter; however, in order to keep this position, it must comply with welfare regulations while maintaining low production costs. Locomotion problems restrain bird movements, limiting their access to drinking and feeding equipment, and therefore their survival and productivity. The objective of this study was to evaluate locomotion deficiency in broiler chickens reared under stressful temperature conditions using three different sampling methods of birds from three different ages. The experiment consisted in determining the gait score of 28, 35, 42 and 49-day-old broilers using three different known gait scoring methods: M1, birds were randomly selected, enclosed in a circle, and then stimulated to walk out of the circle; M2, ten birds were randomly selected and gait scored; and M3, birds were randomly selected, enclosed in a circle, and then observed while walking away from the circle without stimulus to walking. Environmental temperature, relative humidity, and light intensity inside the poultry houses were recorded. No evidence of interaction between scoring method and age was found however, both method and age influenced gait score. Gait score was found to be lower at 28 days of age. The evaluation using the ten randomly selected birds within the house was the method that presented the less reliable results. Gait score results when birds were stimulated to walk were lower than when they were not simulated, independently of age. The gait scores obtained with the three tested methods and ages were higher than those considered acceptable. The highest frequency of normal gait score (0) represented 50% of the flock. These results may be related to heat stress during rearing. Average gait score incresead with average ambient temperature, relative humidity, and light intensity. The evaluation of gait score to detect locomotion problems of broilers under rearing conditions seems subjective and difficult to be properly performed.