Ambiente térmico y bienestar de los cerdos en el período de descanso previo al sacrificio

The research aimed to evaluate the relationship between the thermal environment of the rest pens in a pig slaughterhouse and the surface temperature (ST) of the animals as well as the effect of intermittent water spraying on thermal comfort. There were two visits to slaughter indus- trial being in each selected three pens of rest, one for control treatment (no spray throughout the period) and two for the treatment of intermittent spraying water (30 minutes intervals with constant spray followed by 30 minutes then turned off). Assessments began at the time of discharging animals in which are taken the thermographic images from lots using an infrared thermographic camera. After housing in the pens, were registered the thermographic images and the respiratory frequency (RF) every five minutes for four hours. Were evaluated the temperature, relative humidity and temperature-humidity index (THI). Considering the values of THI was observed that the animals remained in a condition of comfort only at the time of his arrival at the slaughterhouse. The ST and RF of the animals kept in the pens without sprinkler system (control) showed a linear increase in function of time of day, with increasing tempe- rature. The treatment with intermittent sprinkling of water was observed oscillatory behavior of the ST and RF, however it was always lower than the control treatment, even in times when the water sprinklers were turned off. The time required of spray to reduction and stabilization of the ST of the animals was limited to the combination of temperature and relative humidity, being estimated at 25 minutes at times of higher THI. The maximum environmental temperature during evaluation was 28.4 °C.Se evaluó la relación entre el ambiente térmico de las pocilgas de descanso en un matadero de cerdos y la temperatura superficial (TS) de los animales, así como el efecto de la pulverización intermitente de agua sobre el confort térmico. Se llevaron a cabo dos visitas a un matadero comer- cial, y en cada uno de ellos fueron seleccionadas tres pocilgas de descanso, una destinada al tra- tamiento de control (sin pulverizar durante todo el período) y dos para el tratamiento de pulverización intermitente de agua (sucesivamente 30 minutos con aspersión y 30 minutos sin aspersión). Las evaluaciones se iniciaron en el momento de la descarga de los animales, en la cual se registra- ron imágenes termográficas de los lotes con una cámara termográfica infrarroja. Después del alo- jamiento en la porqueriza se registraron imágenes termográficas y la frecuencia respiratoria (FR) de los animales cada cinco minutos durante cuatro horas. También fueron registradas la temperatura y la humedad relativa del aire y se calcularon los índices de temperatura y humedad (ITH). Conside- rando los valores de (ITH) se observó que los animales se mantuvieron en un estado de confort térmico sólo en el momento de su llegada al matadero. La TS y la FR de los animales manteni- dos en la pocilga, sin el sistema de aspersión (control) presentaron una elevación lineal en fun- ción de la hora del día, o sea, conforme al aumento de la temperatura ambiental. En el tratamiento con aspersión intermitente de agua se observó un comportamiento sinusoidal del TS y FR, entretanto las mismas se mantuvieron siempre inferiores al tratamiento control, incluso en los momentos que los rociadores de agua se encontraban desco- nectados. El tiempo de aspersión necesario para la reducción y estabilización de la TS de los animales estuvo condicionado al binomio tempera- tura-humedad relativa del aire, siendo estimado en 25 minutos en los horarios de mayor ITH. La temperatura ambiente máxima durante las evalua- ciones fue de 28,4 oC

Modelos não lineares para a liberação de potássio de estercos animais em latossolos Non linear models to potassium release from animals manure in Latosols

Modelos não lineares são adequados para a descrição da liberação de nutrientes, uma vez que estimam quantidades de interesse prático e apresentam boa qualidade de ajuste. Embora seu processo inferencial seja baseado em argumentos assintóticos, existem meios de se conhecer a intensidade da não linearidade. Neste trabalho, avaliou-se a não linearidade de dois modelos de regressão não linear por meio das curvaturas de Bates e Watts, vício de Box e do estudo das propriedades amostrais dos estimadores de mínimos quadrados, obtido por simulação. Os dados são provenientes do estudo, ao longo do tempo, da liberação de K de quatro estercos animais em combinação com dois solos. O modelo Exponencial foi mais adequado, em termos inferenciais e para aplicação prática, uma vez que por todas as medidas apresentou menor não linearidade.<br>Nonlinear models are appropriate to describe nutrient release, since they estimate quantities of practical interest and they have goodness of fit. Although its inferential process is based on asymptotic arguments, there are ways to know the nonlinearity intensity. In this work, we evaluate the nonlinearity of two nonlinear regression models through the curvatures of Bates e Watts, bias of Box and the least squares estimator sampling properties by simulation study. The data are from the study, over time, of the K release from 4 animal manure in combination with 2 soils. The exponential model was more appropriate in terms of inferential and practical aspects, since by all measures showed lower nonlinearity