Taxa de sudação e parâmetros histológicos de bovinos submetidos ao estresse calórico

Ferreira, Fátima; Campos, Warley Efrem; Carvalho, A.Ú.; Pires, Maria de Fátima Ávila; Martinez, M. L.; Silva, M.V.G.B.; Verneque, R.S.; Silva, P.F.

doi:10.1590/s0102-09352009000400001

Cited by 31 publications

(34 citation statements)

References 5 publications

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“…This may have also been due to a better response to heat stress in this genetic group. Some authors showed that hematological parameters increased during heat stress (Silva et al, 2006;Ferreira et al, 2009), unlike those found in this study. However, the period of analysis for these studies lasted longer and compared mostly warmer seasons with cooler seasons, not within a season with high BGHI.…”

Section: Discussioncontrasting

confidence: 94%

Physiological parameters for thermal stress in dairy cattle

et al. 2016

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-The objective of this study was to investigate changes in physiological parameters of dairy cows and understand which physiological parameters show greater reliability for verification of heat stress. Blood samples were collected for analysis and included hematocrit (Ht), erythrocyte count (ERY), and hemoglobin count (HEMO). In addition, physiological variables, including rectal temperature (RT), heart rate (HR), respiratory rate (RR), and panting score (PS) were recorded in 38 lactating cows. These varied according to genetic group (½, ¾, and pure bred Holstein (HO)). Analysis of variance considering the effects of genetic group, days, and their interaction as well as linear and quadratic effect of the black globe humidity index (BGHI) was performed, as well as broken-line regression. These values were higher in pure HO than in ¾ and ½ groups. The average BGHI during the morning was 74, when 70, 43, and 13% of pure HO, ¾, and ½, respectively, presented RR above reference value. The RR was the best indicator of heat stress and its critical value was 116 breaths/min for ½, 140 for ¾, and 168 breaths/min for pure HO cows. In the HO group, physiological variables increased linearly with BGHI, without presenting inflection in the regression. The inflection point occurred at a higher BGHI for the ½ group compared with the other groups. Hematocrit and HEMO were different among genetic groups and did not vary with BGHI, showing that stress was not sufficient to alter these hematological parameters. The ½ HO group was capable of maintaining normal physiological parameters for at least 3 BGHI units above that of HO and 1 to 3 units higher than ¾ HO for RR and RT, respectively. Respiratory rate is the physiological parameter that best predicts heat stress in dairy cattle, and the 1/2 Holstein group is the best adapted to heat stress.

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Section: Discussioncontrasting

confidence: 94%

Physiological parameters for thermal stress in dairy cattle

et al. 2016

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“…O número de animais, o local de realização do experimento, o período de estudo e as condições de estresse a que os animais foram submetidos foram descritos por Ferreira et al (2009).…”

Section: Methodsunclassified

Parâmetros clínicos, hematológicos, bioquímicos e hormonais de bovinos submetidos ao estresse calórico

Ferreira¹,

Campos²,

Carvalho³

et al. 2009

Arq. Bras. Med. Vet. Zootec.

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“…However, the season in the year can influence it, with less depth in the summer because of the increase in the activity of the gland (Ferreira et al, 2009).…”

Section: Resultsmentioning

confidence: 99%

Effects of age on histological parameters of the sweat glands of Nellore cattle

Regina

Nascimento²,

Dias³

et al. 2015

Rev. Ceres

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RESUMO Effects of age on histological parameters of the sweat glands of Nellore cattleThe sweat glands are important in thermoregulation of cattle in a warm environment as they help dissipate heat through evaporation. Studies on gland histology are important to define its secretion potential and the capacity of perspiration and heat removal. The objective of this study was to determine, by histomorphometry, glandular epithelium height, the depth of the gland, length of the glandular portion and number of glands per cm 2 of the sweat glands of the three age groups of Nellore cattle. Thirty females were used in this study. They were equally divided into calves, heifers and cows. Histological sections were obtained and analyzed by digital images in Trinocular BX40 Olympus microscope coupled to an Oly -200 camera, connected to a computer. The images were obtained with microscope with 2x, 4x, 10x and 40x magnification objectives. The measurements were performed using HL Image 97 program. The height of glandular epithelium, depth of the glands, length and density of the glandular portion per cm 2 , were all analyzed. The calves showed greater height of the glandular epithelium than heifers (P = 0.0024), and cows (P = 0.0191). The depth of the gland was not influenced by age. Cows had higher length of secretory portion than heifers (P = 0.0379) and calves (P = 0.0077). Heifers had a greater number of sweat glands per cm 2 of skin than cows (P = 0.023). In cattle, the height of glandular epithelium and the density decreases as animals get older. On the other hand, the length of the secretor portion increases but with no changes in the depth of the sweat glands.

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Taxa de sudação e parâmetros histológicos de bovinos submetidos ao estresse calórico

Abstract: Taxa de sudação e parâmetros histológicos de bovinos submetidos ao estresse calórico

Cited by 31 publications

References 5 publications

Physiological parameters for thermal stress in dairy cattle

Physiological parameters for thermal stress in dairy cattle

Parâmetros clínicos, hematológicos, bioquímicos e hormonais de bovinos submetidos ao estresse calórico

Effects of age on histological parameters of the sweat glands of Nellore cattle

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