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dc.contributor.author | Du Preez, J.H. | |
dc.contributor.editor | Verwoerd, Daniel Wynand | |
dc.date.accessioned | 2012-09-27T10:37:41Z | |
dc.date.available | 2012-09-27T10:37:41Z | |
dc.date.created | 2012 | |
dc.date.issued | 2000 | |
dc.description | The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format. | en |
dc.description.abstract | Not all parameters are trustworthy and practical to use as parameters to determine heat stress in dairy cattle. The temperature-humidity index (THI) is still the best, simplest and most practical index (parameter) for measurement of environmental warmth which cause heat stress in dairy cattle. It is practical, easy to determine and relatively trustworthy to use body temperature and respiratory rate as parameters to determine heat stress in dairy cattle. These physiological parameters must always be used together with THI values to determine and evaluate heat stress in dairy cattle. For practical purposes, plasma cortisol concentration and milk composition cannot be used as parameters to determine heat stress in dairy cattle although good indications of acute or chronic heat stress can be obtained. Vanillic acid is a break-down product of adrenalin found in milk, but before its concentration in milk can be used as an indicator/parameter of heat stress in dairy cows, more about the pharmacodynamics of adrenaline in the milk has to be known. Selection and breeding of dairy cows on the basis of their adaptibility to heat stress using the most practical heat stress parameters will ensure that their offspring will have superior performance in the prevailing environmental conditions. | en |
dc.description.librarian | mn2012 | en |
dc.identifier.citation | Du Preez, JH 2000, 'Parameters for the determination and evaluation of heat stress in dairy cattle in South Africa’. Onderstepoort Journal of Veterinary Research, vol. 67, no. 4, pp. 263-271. | en |
dc.identifier.issn | 0330-2465 | |
dc.identifier.uri | http://hdl.handle.net/2263/19903 | |
dc.language | en | |
dc.publisher | Published by the Agricultural Research Council, Onderstepoort Veterinary Institute . | en |
dc.rights | © ARC-Onderstepoort (original). © University of Pretoria. Dept of Library Services (digital). | en |
dc.subject | Veterinary medicine | en |
dc.subject | Body temperature | en |
dc.subject | Cortisol | en |
dc.subject | Heat stress parameters | en |
dc.subject | Respiratory rate | en |
dc.subject | Temperature-humidity index | en |
dc.subject | Vanillic acid | en |
dc.subject.lcsh | Veterinary medicine -- South Africa | |
dc.subject.lcsh | Cattle -- Diseases | en |
dc.title | Parameters for the determination and evaluation of heat stress in dairy cattle in South Africa | en |
dc.type | Article | en |