Evaporação cutânea e respiratória em ovinos sob altas temperaturas ambientes

Silva, Alexandre Rodrigues; Starling, J. M. C.

doi:10.1590/s1516-35982003000800020

Cited by 37 publications

(34 citation statements)

References 12 publications

(6 reference statements)

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“…Veríssimo et al (2009) found that Santa Ines ewes with light coat with brown spots had skin pigmentation that accompanied the hair coat, unlike the tropical cattle breeds that tend to have highly pigmented skin in combination with white or light coat. This is a consequence of natural selection, which aims to protect the deep tissues of the dangerous action of ultraviolet radiation of short wavelength (<300 nm), which readily crosses the thin layer of coat of these animals (SILVA; STARLING, 2003).…”

Section: Resultsmentioning

confidence: 99%

Breed comparison for heat adaptation in rams using multivariate analysis

Júnior¹,

Lucci²,

Peripolli³

et al. 2016

Biosci. J.

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ABSTRACT:In this study, a multivariate analysis of morphological and physiological characteristics was performed on clinically healthy rams from six breeds (Santa Ines, Bergamasca, Dorper, Texel, Ile de France and Hampshire Down) to determine if these characteristics were able to separate and determine the most important variables in the differentiation of breeds for heat adaptation. To characterize the thermal environment, mean temperature was 23°C and relative humidity ranged between 30.6-55.6%. Morphological and physiological data were subjected to multivariate statistical tests including principal components (PRINCOMP), clustering (CLUSTER), discriminant (DISCRIM), step-bystep (STEPDISC) and canonical (CANDISC) analyses, using the Statistical Analysis System (SAS®). A multiple analysis of variance (MANOVA) was carried out with the variables defined as important by the discriminant analysis. The principal components analysis for biometric characteristics and scrotum-testicle, for physiological characteristics and body temperature as well as the characteristics of the skin and hair explained 60, 70 and 67 % of the total variation, respectively. The dendrogram showed a clear separation between the breeds studied and the existence of two distinct groups, one formed by the Texel and the other by the other breeds, considering all the characteristics used in the study. The most useful morphological parameters to explain heat tolerance were diameter of hair, layer thickness of hair at withers, 12th thoracic vertebra and rump, withers height, thoracic and scrotal circumferences, body weight, anterior and posterior shin perimeters, hair and epidermis brightness as well as the content of red and yellow in the epidermis. Among physiological characteristics, respiratory rate was better than rectal temperature and heart rate to explain changes caused by thermal stress. From the multivariate and variance analyzes it can be concluded that the Santa Ines breed was the most tolerant to heat stress as it presented a highly pigmented epidermis, a shorter hair of larger diameter, the lower layer thickness of hair at withers, 12th thoracic vertebra and rump, the lower temperatures in the testicle and at the 12th thoracic vertebra as well as the lower respiratory rate and rectal temperature value.

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Section: Resultsmentioning

confidence: 99%

Breed comparison for heat adaptation in rams using multivariate analysis

Júnior¹,

Lucci²,

Peripolli³

et al. 2016

Biosci. J.

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show abstract

“…Silva and Starling (2003) emphasized the importance of respiratory stabilization; high respiratory rates over a long period of time can cause a reduction in blood pressure of CO 2 , in addition to increasing the heat accumulated in the tissues due to rapid work of respiratory muscles. The reduction in blood pressure is responsible for the increased heart rate in an attempt to maintain blood pressure at the physiological level considered normal.…”

Section: Resultsmentioning

confidence: 99%

Feeding behavior and responses in grazing lactating cows supplemented with peanut cake

et al. 2015

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-This experiment was conducted to study the substitution of soybean meal with peanut cake in the supplement by assessing the feeding behavior and the interaction between the thermal environment and the physiological responses of eight crossbred cows with an average live weight of 500 kg. Cows were divided into two 4 × 4 Latin squares and managed on pasture. The peanut cake was included at the levels of 0, 330, 660, and 1,000 g kg −1 in the supplement as a replacement for soybean meal. The feeding behavior variables were not affected by the levels of peanut cake. No differences were found for the physiological parameters of the animals with the replacement of soybean meal for peanut cake in the supplements. Peanut cake can replace up to 100% soybean meal in the supplement of grazing lactating crossbred cows without altering the feeding behavior or physiological parameters of the animals.

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“…Recentemente experimento realizado com ovinos lanígeros da raça Corriedale em ambientes com altas temperaturas, a evaporação cutânea torna-se um mecanismo mais eficiente para a perda de calor, contribuindo em média com 63% (81g.h1.kg1) da evaporação total (SILVA; STARLING, 2003 …”

Section: Revisão Bibliográfica Características Gerais Da Espécie Ovinaunclassified

Assessment bioclimatology in sheep

Santos¹,

Macedo²,

Vaz³

et al. 2016

Pubvet

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ResumoA ovinocultura esta amplamente distribuída pela as regiões do país, onde fatores climáticos afetam os animais diminuindo assim a produtividade, em consequência dos animais estarem fora da zona de conforto térmico. O organismo animal gasta energia nos mecanismos fisiológicos para esfriar ou aquecer o corpo, os nutriente ingeridos pelos animais transformados em energia, sendo que parte desta energia formada será translocada para os mecanismos fisiológicos, em detrimento da energia necessária para o crescimento e desenvolvimento. O estresse por calor influencia no consumo voluntário dos alimentos pelos animais.Palavras-chave: adaptação, desempenho, estresse térmico, tolerância. SANTOS, R.P. et al. Avaliação bioclimatológica em ovinos. PUBVET, Londrina, V. 6, N. 20, Ed. 207, Art. 1382, 2012 Assessment bioclimatology in sheep AbstractThe sheep production is widely distributed throughout the regions of the country, where climatic factors affect the animal thereby reducing productivity as a consequence of the animals is outside the zone of thermal comfort. The organism spends energy in animal physiological mechanisms to cool or warm the body, the nutrients ingested by the animal turned into energy, and part of this energy form is translocated to the physiological mechanisms, to the detriment of energy needed for growth and development. The heat stress influenced on the voluntary intake of food by animals.Keywords: adaptation, performance, thermal stress, tolerance INTRODUÇÃOO fator mais importante na determinação do clima é a posição geográfica do país. A maior parte do Brasil fica entre a linha do Equador, que corta o país na Região Norte, e o trópico de Capricórnio, que passa no Sudeste. As regiões do planeta que ficam entre essas duas linhas têm climas quentes e úmidos, e climas quentes e secos com temperatura media de 20ºC. Nas proximidades do Equador, são comuns temperaturas mais altas, sem grandes variações ao longo do ano. Já em regiões mais ao sul, as variações de temperatura são maiores. Outros fatores também podem interferir no clima, como altitude, proximidade do mar, presença de montanhas, ventos e massas de ar. (PEREIRA, 2005).A temperatura do ar é considerada o fator climático com influencia mais importante sobre o ambiente físico do animal (MCDOWELL, 1974). Dentro de ampla faixa de temperatura, podem ser definidas zonas térmicas que proporcionam maior ou menor conforto ao animal. Os animais para terem máxima produtividade, dependem de uma faixa de temperatura adequada, também chamada de zona de conforto térmico, em que não há gasto de energia ou atividade metabólica para aquecer ou esfriar o corpo. Do ponto de SANTOS, R.P. et al. Avaliação bioclimatológica em ovinos. PUBVET, Londrina, V. 6, N. 20, Ed. 207, Art. 1382, 2012 vista de produção, este aspecto reveste-se de muita importância, pelo fato de que dentro desses limites, os nutrientes ingeridos pelos os animais serem utilizados exclusivamente para seu crescimento e desenvolvimento (BAÊTA; SOUSA, 1997).A umidade atmosférica é outra variável q...

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Evaporação cutânea e respiratória em ovinos sob altas temperaturas ambientes

Cited by 37 publications

References 12 publications

Breed comparison for heat adaptation in rams using multivariate analysis

Breed comparison for heat adaptation in rams using multivariate analysis

Feeding behavior and responses in grazing lactating cows supplemented with peanut cake

Assessment bioclimatology in sheep

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