Morpho-physiological responses of Bos indicus, Bos taurus and crossbred weaned heifers to seasonal variations

Animals kept in extensive production systems are constantly exposed to the effects of climatic aspects, which could favour thermal discomfort, decreasing productive and reproductive performances. Utilisation of Bos taurus crosses with Bos indicus animals is increasing in the tropics aimed at improving production and it is now well known how these animals respond in such environment. The objective was to characterize the morpho-physiological thermoregulation responses of weaned heifers from four different genetic groups to infer regarding the different degrees of adaptation to heat under tropical conditions Forty-eight, pasture-kept, 6-month-old, weaned heifers from four distinct genetic groups: (1) Nellore; (2) Senepol; (3) Angus x Nellore; and, (4) ¼ Brahman x ¼ Nellore x ½ Senepol (Tri-cross) were evaluated. Skin, hair coat and rectal temperatures; sweating rate; respiratory and heart rates; visual analysis of hair and hair coat colour; hair coat temperature and thickness; and length, diameter, density and number of hairs were evaluated. In addition, the temperature-humidity index, black-globe temperature and humidity index, and radiant thermal load were determined. Angus x Nellore animals presented the lowest (P=0.008) respiratory rate. Rectal temperature did differ (P=0.001) between seasons. Angus x Nellore heifers showed the greatest (P=0.001) values for the morphological measures in the evaluated months, coinciding with thermal comfort indexes above those considered comfortable for cattle.  Nellore (Bos indicus), Brahman x Nellore x Senepol, and Senepol (B. taurus) present the best adaptive traits in savanna. The utilisation of B. indicus animals or adapted breed confers desirable morphological characteristics for the tropical environment. Beef cattle kept in extensive systems are constantly exposed to the effects of the climate. In tropical and intertropical regions, the reproductive management of Bos taurus animals with B. indicus animals is an alternative for zootechnical improvement. The objective was to evaluate morphophysiological characteristics of heat adaptation of beef heifers on pasture. For this, fifty-four animals from four distinct genetic groups: (1) Nellore, (2) Senepol, (3) Angus x Nellore and (4) ¼ Brahman x ¼ Nellore x ½ Senepol (Tri-cross), with six months-old, were evaluated during the summer and autumn seasons of 2016. The morphological characteristics of the coat (length, diameter, thickness, density and number of hairs and coat color) and physiological (skin, hair and rectal temperature; sweat rate; respiratory and heart rate) were evaluated. The environment was evaluated using the temperature and humidity index, black globe temperature, humidity index and radiation thermal load. We observed that the production environment presented thermal discomfort for the animals. Thus, the animals’ rectal temperature differed between seasons. All groups studied showed some adaptive characteristic to the tropical environment. Angus x Nellore heifers had the highest values for the morphological measures in the months evaluated, coinciding with thermal comfort indexes above those considered comfortable for cattle and the lowest value of respiratory rate when compared between the crossing. In conclusion, all genetic groups have at least three adaptive characteristics to the tropical environment when analyzing the physiological responses

Rastreamento de fontes de contaminação do leite cru em diferentes pontos do processo de produção

The present work was objective to evaluate the quality of refrigerated raw milk through microbiological swabs being used at three different points of milking, which were represented by the liner (last set), tank and hose connected to the container end unit before and after the adoption of procedures for cleaning equipment. The experiment was conducted in period of May to June, 2009, in five milk properties, all situated in Parana west region. The data have been obtained by: check list and; analysis of the diverse points of production with research of mesophilic and psychrotrophic microorganisms. The cleaning is not seen by producers as generating element of quality. The main contamination points were then liner hose connected to the tank. In the samples of milk collected, one was out of the microbiological standards established by law.O presente trabalho teve como objetivo avaliar a qualidade do leite cru refrigerado, por meio de análises microbiológicas sendo utilizados swabs em três pontos distintos da ordenhadeira, sendo estes representados pela teteira (último conjunto), mangueira conectada ao tanque e recipiente da unidade final, antes e após a adoção dos procedimentos de higienização do equipamento.  O experimento foi realizado no período de maio a junho de 2009, em cinco propriedades leiteiras, todas situadas na região oeste do Paraná. Os dados obtidos foram por meio de check list e análise dos diversos pontos de produção sendo avaliados os micro-organismos mesófilos e psicrotróficos. A higienização não é vista pelos produtores como elemento gerador de qualidade. Os principais pontos de contaminação foram teteira seguida da mangueira conectada ao tanque. Com relação às amostras de leite coletadas, uma delas estava fora dos padrões microbiológicos estabelecidos pela legislação vigente

Potencial do uso de termografia por infravermelho para investigação térmica do ambiente rural

<p>O uso de tecnologias e ferramentas para estudos de ambiência no setor rural ganha impulso à medida que temas como bem-estar animal e conforto térmico despertam o interesse e necessidade de mudanças no setor produtivo. Neste contexto, a termografia por infravermelho surge como alternativa para se inferir sobre as modificações microclimáticas aportadas pelas espécies arbóreas em pastagens, com precisão e rapidez no processo. Objetivou-se neste trabalho avaliar o uso da câmera termográfica para mensuração da temperatura do ar e estimativa do conforto térmico proporcionado por diferentes espécies arbóreas. O experimento foi conduzido na Embrapa Gado de Corte, Campo Grande-MS, de junho a agosto de 2015. Foram avaliadas 4 espécies arbóreas nativas do Cerrado brasileiro quanto aos parâmetros microclimáticos e índices de conforto térmico proporcionados por suas sombras. Os dados coletados foram submetidos à análise fatorial múltipla. Foi observada correlação linear positiva e forte entre a termografia e medidas de temperatura (0,854), termografia e índices de conforto térmico (0,778) e termografia e radiação solar (0,768). A termografia por infravermelho mostrou-se um potencial preditor das variáveis microclimáticas e de conforto térmico proporcionado por espécies arbóreas.</p