Spatial variability and exploratory inference of abiotic factors in barn compost confinement for cattle in the semiarid.

The assessment of environmental conditions in the creation of dairy cattle in feedlots must be carried out to identify possible causes of stress and assist producers in the decision-making process. The objective was to characterize the abiotic factors and bed temperature, in the comfort conditions of dairy cows, through geostatistics and exploratory data inference, in a Compost Barn System in the Brazilian semiarid region. The data were obtained in a milk production unit, located in the municipality of Lajedo, Pernambuco, Brazil. The variables air temperature (Tair), relative humidity (RH), wind speed (WS), illuminance (Lux), skin temperature (Ts), bed temperature (Tb) were recorded and the temperature index was determined and humidity (THI). Data were recorded at 9:00 a.m., 12:00 p.m., and 03:00 p.m., over 5 days in the summer season. For geostatistical analysis, the classic semivariances were determined. The principal component analysis was performed to establish an index that characterized the condition of animal comfort. The variables Tair, RH, Tb, and THI showed a low coefficient of variation for all times. The best fit to the models of the semivariograms was the Gaussian at 9:00 a.m. and 03:00 p.m., and the spherical at 12:00 p.m. The Tb spatial variability was low for all studied hours. Tair showed a strong correlation with Tb, due to the process of heat transfer by convection from the floor to the environment. Geostatistics and exploratory data analysis allowed the establishment of a comfort index for Compost Barn production systems in the Brazilian semiarid region (R2 = 0.996; p < 0.0001).

Sistema de confinamento Compost barn: interações entre índices de conforto, características fisiológicas, escore de higiene e claudicação / Compost barn housing systems: interactions among comfort indexes, physiological characteristics, hygiene score, and claudication / Sistema de confinamiento Compost barn: interacciones entre índices de confort, características fisiológicas, puntuación de higiene y claudicación

O objetivo desse artigo foi avaliar o conforto térmico de bovinos leiteiros confinados em instalações Compost Barn com base em índices de conforto térmico, parâmetros fisiológicos, escore de higiene e claudicação. A pesquisa foi realizada, em uma propriedade do município de Três Corações no estado de Minas Gerais no período de verão e inverno de 2016. As variáveis microclimáticas e os escores de limpeza e de locomoção foram analisadas por meio da estatística descritiva. Os parâmetros fisiológicos foram submetidos a um delineamento experimental em blocos casualizados em parcela subdividida no tempo, por meio da análise de variância e teste de Scott-Knott. Pode-se concluir que não ocorreu estresse térmico nos animais na estação de verão e inverno. Os parâmetros fisiológicos se encontraram dentro dos limites de conforto animal. Existe um relacionamento maior entre a frequência respiratória, temperatura superficial e temperatura retal e os índices de conforto animal no verão, quando comparada com o inverno. Para a análise dos escores, as vacas apresentaram uma melhoria na limpeza e um número muito baixo de vacas com problemas de cascos.(AU)

The purpose of this article is to evaluate the thermal comfort of dairy cattle confined in compost barn facilities based on thermal comfort indexes, physiological parameters, hygiene score, and claudication. The research was carried out in a property in the city of Três Corações in the state of Minas Gerais during the summer and winter of 2016. The microclimatic variables and the cleaning and locomotion scores were analyzed through a descriptive statistics analysis. The physiological parameters were submitted to an experimental design in randomized blocks in a subdivided plot, using analysis of variance and Scott-Knott's test. It can be concluded that no thermal stress occurred on the animals during the summer and winter seasons. There is a greater relationship between respiratory rate, surface and rectal temperature, and the animal comfort indexes in summer compared to winter. For the analysis of the scores, the cattle showed an improvement in cleaning and a very low number of cows presented hoof problems.(AU)

El objetivo de este artículo es evaluar el confort térmico de bovinos lecheros confinados en instalaciones Compost Barn con base en índices de confort térmico, parámetros fisiológicos, puntuación de higiene y claudicación. La investigación se realizó en una propiedad del municipio de Tres Corações en el estado de Minas Gerais, en el período de verano e invierno de 2016. Las variables microclimáticas y los escores de limpieza y de locomoción fueron analizados por medio de estadística descriptiva. Los parámetros fisiológicos fueron sometidos a un delineamiento experimental en bloques casualizados en parcela subdividida en el tiempo, por medio del análisis de varianza y prueba de Scott-Knott. Se puede concluir que no ocurrió estrés térmico en los animales en la estación de verano e invierno. Los parámetros fisiológicos se encontraron dentro de los límites de confort animal. Hay una relación mayor entre la frecuencia respiratoria, la temperatura superficial y la temperatura rectal y los índices de confort animal en verano, en comparación con el invierno. Para el análisis de los escores, las vacas presentaron mejora en la limpieza y un número muy bajo de vacas con problemas de cascos.(AU)

Research Note: Metabolic changes and physiological responses of broilers in the final stage of growth exposed to different environmental temperatures.

There is no information regarding the influence of heat stress (HS) on host metabolic profile. In this study, we investigated the effects of different environmental temperatures on oxidative status, hormone levels, HS indicators, and plasma metabolites in broilers. A total of 1,680 yellow-feather broilers (28 D old) were randomly allotted to 4 groups with 6 replicates. The broilers (29-57 D old) were maintained in thermostatic rooms (20°C, 25°C, 28°C, and 30°C) for 28 consecutive days. The results showed that the plasma cortisol and adrenocorticotropic hormone levels and creatine kinase and lactate dehydrogenase activities gradually increased when the temperature increased from 20°C to 30°C. However, the insulin-like growth factor-І level decreased gradually. Furthermore, heat shock protein 70 expression significantly increased in the liver and breast muscle (P < 0.01). As the temperature increased, the total anti-oxidant capacity in the plasma and liver gradually decreased, whereas the malondialdehyde level increased. The activity of plasma glutathione peroxidase and total superoxide dismutase in the liver showed a similar increasing trend (P < 0.01). In addition, 15 metabolites were identified at higher (P < 0.05) levels, whereas 2 metabolites were identified at lower (P < 0.05) levels in the 30°C treatment group than those in the 25°C treatment group. Most of these potentially diagnostic biomarkers are involved in carbohydrate, amino acid, lipid, or gut microbiome-derived metabolism, indicating that HS affected the metabolic pathways in broilers. Six candidate metabolites (tartronic acid, l-bethreine, tartaric acid, allose, glutaric acid, and neohesperidin) were selected as biomarkers, as they showed high sensitivity, specificity, and accuracy in diagnosing broilers under HS (P < 0.01). In conclusion, in the final stage of growth, we identified 6 plasma differential metabolites as potential biomarkers of HS-induced metabolic disorders in yellow-feathered broilers. This work offers new insights into the metabolic alterations of broilers exposed to HS and provides a new perspective for further study.