The function of cattle sweat glands.

Ferguson, KA; Dowling, D. F.

doi:10.1071/ar9550640

Cited by 57 publications

(32 citation statements)

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“…It is possible to determine the air-flow rate at which AT = 0; this 'critical flow rate' gives ventilation inside the capsule equivalent to that outside it. The critical flow rate determined at this air temperature may be still valid at other air temperatures; but the condition AT = 0 is no longer applicable, & Robinson, 1955;e Taneja, 1958;f Kibler & Yeck, 1959;g McDowell, Lee & Fohrman, 1954;h, McDowell, McDaniel, Barrada & Lee, 1961;j, Taneja, 1959;k, Ferguson & Dowling, 1955. 27-2 420 J. A. McLEAN since radiative loss is now altered by the application of the capsule.…”

mentioning

confidence: 99%

Measurement of cutaneous moisture vaporization from cattle by ventilated capsules

McLean¹

1963

The Journal of Physiology

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Methods of measuring cutaneous moisture vaporization fall broadly into two categories, direct and indirect.Direct methods are those in which the moisture loss from a small area is measured by placing an inverted cup or capsule over that area. The capsules may be ventilated or unventilated. In the ventilated capsule the rate of evaporation is usually determined by passing dry air into the capsule and measuring the gain in weight of a moisture absorber through which the outlet air is passed, for a period of 5-20 min. McDowell, Lee & Fohrman (1954) criticized the use of dry inlet air, because with this the skin under test is exposed to abnormal atmospheric conditions. To overcome this they recirculated air round a closed circuit incorporating a capsule and an absorption bottle, the latter containing a saturated salt solution. The factors influencing the choice of air flow through ventilated capsules do not appear to have received enough attention. Air-flow rates appear to have been chosen to suit the absorbers used, with little consideration of the effect this variable may have on the rate of evaporation within the capsule.In the unventilated capsule air-flow rate is at least standardized, although at a level below that to which surrounding skin areas are exposed. Unventilated capsules normally contain a pad of desiccant material which is weighed at intervals. This method has been critically analysed by Randall, Peiss & Hertzman (1953), who showed that the quantity of desiccant used, and the distance between the desiccant and the skin surface, affected the observed rate of evaporation.A disadvantage common to most capsule methods is that the measurement of evaporation, since it depends on the gain in weight of an absorber, can be made only over periods of several minutes. Indirect methods are those in which cutaneous evaporation is calculated by difference from simultaneous measurements of total evaporation and respiratory evaporation. The hygrometric tent (Kibler & Yeck, 1959) is 27 Physiol. 167

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confidence: 99%

Measurement of cutaneous moisture vaporization from cattle by ventilated capsules

McLean¹

1963

The Journal of Physiology

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“…The increased rate of loss of moisture from the skin after the injection of adrenaline must therefore have been due to the active expulsion of moisture from sweat glands or sebaceous glands in the thorax and shanks. The active secretion of sweat from the skin of cattle has been observed before by Ferguson & Dowling (1955), who examined the orifices of the sweat glands under a stereo microscope during intradermal injections of adrenaline. Evans & Smith (1956) have demonstrated that the sweat glands in the horse normally respond to an increase in the amount of adrenaline in the blood or to increased blood supply, and that factors which increase skin circulation therefore favour or cause sweating.…”

Section: The Effects Of Localized Infra-red Irradiationmentioning

confidence: 99%

The effect of heating the hypothalamus and the skin on the rate of moisture vaporization from the skin of the ox (Bos taurus)

Ingram¹,

McLean²,

Whittow³

1963

The Journal of Physiology

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Localized heating of the hypothalamus of the ox causes an increase in the rate of moisture vaporization from the skin of the trunk when the environmental temperature is between 10 and 200 C (Ingram, McLean & Whittow, 1961). The increased moisture loss from the skin is associated with an increase in the skin temperature. It is uncertain whether the increase in cutaneous moisture loss is a direct effect of increased hypothalamic temperature or whether it is a secondary effect of increased skin temperature. Nor is it known whether changes in the temperature of the hypothalamus play any part in the regulation of cutaneous moisture loss in the ox under normal conditions. The rate of cutaneous moisture loss also increases when the environmental temperature is increased, but it is again uncertain whether the increased moisture loss is a result of a change in hypothalamic or skin temperature.When the rump and flanks are exposed to infra-red irradiation increases in the skin temperatures of the unheated extremities of the ox can occur before the temperature of the blood in the bicarotid trunk increases (Ingram & Whittow, 1962b). If the increase in skin temperature is the cause of increased loss of moisture from the skin, then increased moisture vaporization from the unheated extremities should also occur in the absence of any change in the brain temperature.The experiments described in this paper were undertaken (a) to provide more information about the effects of heating the hypothalamus on loss of moisture from the skin at different environmental temperatures, (b) to see whether loss of moisture can increase in the absence of a change in skin temperature, and (c) to see whether the rate of evaporation of moisture from the skin can be correlated with the temperature of the hypothalamus.

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“…The relationship between sweating rate and rectal temperature was greater for Brahman cattle (B) than for the Brahman cross Shorthorn (BX) or Shorthorn cattle (S). The density of sweat glands in Bos indicus is higher than in European cattle (Ferguson & Dowling 1955;Nay and Hayman 1956). Nay and Hayman (1956) found that Bos indicus cattle had larger and more numerous sweat glands than Bos taurus cattle.…”

Section: The Effects Of Heat Load On Different Breeds Of Cattle (Bos mentioning

confidence: 99%

“…Others have shown that a sweating mechanism is in fact present (Dowling 1955a(Dowling , 1955bFerguson & Dowling 1955;Taneja 1956;Dowling 1958). …”

Section: Sweatingmentioning

confidence: 99%

Heat load alleviation in beef cattle: water application during continuous high temperature exposure

Tait¹

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The live export industry is an integral part of the Australian cattle industry and makes a significant contribution to the Australian economy. Heat stroke has been a major cause of cattle death on long haul sea voyages and has the potential to threaten the viability and sustainability of cattle exports.To mitigate high heat loads on these voyages, it is necessary to implement cooling strategies to lower the temperature of the microclimate surrounding the cattle. The main cooling method used on live export voyages is high pressure hosing but no research has been undertaken to evaluate the efficacy of this or other water application methods. The major focus of this thesis was therefore, to explore heat load mitigation of confined beef cattle. The initial hypothesis was that the application of water onto cattle exposed to a continuous high heat load will reduce the severity of heat stress.As, different breeds of cattle and composites are exported together, the second hypothesis was that different cattle breeds and composites respond differently to heat exposure and to water cooling.Climatic conditions for all three studies were based on the conditions encountered on board a live export vessel travelling from southern Australia to the Middle East (during the northern hemisphere summer). The first study obtained data on changes in the microclimate and responses of Bos taurus cattle (Angus) when water was applied via a hose to cattle maintained in single pens under continuous hot conditions. The results showed that the water application had a positive impact on cattle comfort (respiratory rate reduced by 50 -80 bpm; rectal temperature reduced within an hour after wetting of cattle). The dry-bulb temperature was also reduced following longer duration water applications. The impact of water application on physiological parameters, such as rate of respiration and rectal temperature, was a function of water volume applied and ambient conditions. For all steers mean daily rectal temperatures and respiratory rates were lower (P < 0.01) during thermoneutral conditions than during the 11 days of hot conditions. Four water application methods (hosing, overhead sprinklers, leg sprinklers and misters) were evaluated in the second experiment with the same Bos taurus breed. Volume and frequency of water application was assessed with the cattle were housed in groups (n = 9) on sawdust bedding. Of the four methods evaluated, hosing was the most effective in mitigating the heat load on the cattle. The leg wetting and misting treatments had little to no effect. While not as effective as hosing, overhead sprinklers did afford heat relief and may have advantages for cooling large numbers of cattle at the same time. Bedding had to be removed after it became wet due to increased concentrations of atmospheric ammonia that posed a risk to cattle and human health. IIAs live export ships carry both Bos taurus and Bos indicus cattle, the third experiment investigated the effects of high heat load conditions on three breeds of cattle an...

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The function of cattle sweat glands.

Cited by 57 publications

References 1 publication

Measurement of cutaneous moisture vaporization from cattle by ventilated capsules

Measurement of cutaneous moisture vaporization from cattle by ventilated capsules

The effect of heating the hypothalamus and the skin on the rate of moisture vaporization from the skin of the ox (Bos taurus)

Heat load alleviation in beef cattle: water application during continuous high temperature exposure

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