The use of urea as a marker of body water in the nursing foal

Geerken, C. M.; Doreau, M.; Boulot, Sylviane; Dubroeucq, H.; Lefaivre, Renée

doi:10.1051/rnd:19880206

Cited by 6 publications

(6 citation statements)

References 10 publications

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“…This is consistent with a report on healthy foals, where the urea space method had a higher error variation than the tritiated water method, where the tritiated water method was a higher cost, and more labour intensive technique (Geerken et al, 1988b). It was found that for all extreme urea space as a percentage of live weight values (i.e., <52% or >215%), there were obscure increases in plasma urea values (7.0 ± 7.6 mmol/L and 0.9 ± 0 mmol/L, respectively), for the 12 minutes after urea infusion.…”

Section: Measuring Milk Uptakesupporting

confidence: 92%

“…For example, in two-month-old nursing foals, mean urea space was 4% less than tritiated water space. Standard deviation for the proportion of water to body weight was higher with the urea space (3.8%) than tritiated water space (1.6%) (Geerken et al, 1988a).…”

Section: Observing and Quantifying Hydration Status In Neonatal Calvesmentioning

confidence: 82%

“…Compared with tritiated water, urea solutions are easier to prepare and are analysed with greater ease (Geerken et al, 1988a).…”

Section: Observing and Quantifying Hydration Status In Neonatal Calvesmentioning

confidence: 99%

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Dehydration as a risk factor for calf mortality in northern Australia

Muller¹

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It is estimated that approximately one million calves die in Australia every year, with the majority unexplained. This thesis reviews losses associated with dehydration-mediated mortality during neonatal life, when there is highest risk of mortality, and reports three studies of neonatal calf dehydration.For 12 neonatal Brahman calves at Spyglass research site (northern forest land type, Queensland), variation in hydration status was investigated (Experiment 1). Change in live-weight from birth was used as the primary measure of hydration. Half of this cohort had low live weight gain between birth and day 3 of life (p = 0.01) compared to calves growing at 0.95±0.24 kg/day from birth. Low growth and associated reduced plasma protein (p = 0.04) in 6 calves indicated reduced colostrum, milk uptake and therefore reduced body fluid replenishment compared to other calves. This positions them at high risk of mortality under adverse environmental conditions. Urea space was tested as a measure of body water; however, percentage body water estimates were unrealistically elevated (> 80% of live weight) and therefore not representative of actual calf percentage body water.Descriptive analysis of risk factors for calf mortality was conducted for 478 and 378 tropically adapted newborn calves, respectively at Spyglass and Brian Pastures (southern forest land type, central Queensland) research sites (Experiment 2). The incidence risk of neonatal mortality in the southern forest of Queensland and northern forest of Queensland was 3.1% and 4.7%, respectively. Some risk factors and the percentage of calves exposed to high mortality risk included: dam body condition score ≤2 (8%), birth weight ≤28 kg (18%), low birth vigour (2%), large udder size (1%), at least two large teats (2%) and poor maternal protectiveness (5%). The low proportion of cows in poor body condition and good nutritional management limited the opportunity for dehydration-mediated neonatal mortality. There were no cases of prolonged heat stress around calving at the level previously associated with foetal and calf mortality. Experiment 2 indicates that low calf mortality may be achieved in any country type, provided that a low proportion of calves are exposed to high risk of mortality. A simple mechanistic model was developed to describe milk uptake volumes and ambient temperature (heat stress) impacts on neonatal hydration. This model provided clarification for the possible risk of dehydration mediated mortality across breeding herds of northern Australia.This thesis demonstrated variation in milk delivery, modelled that low milk delivery is associated with dehydration-mediated mortality and demonstrated that risk of mortality is low at a herd level when the risk factors associated with reduced milk delivery have low frequency.3

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Section: Measuring Milk Uptakesupporting

confidence: 92%

Section: Observing and Quantifying Hydration Status In Neonatal Calvesmentioning

confidence: 82%

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Dehydration as a risk factor for calf mortality in northern Australia

Muller¹

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“…À l'opposé de résultats obtenus sur poulain (Geerken et al, 1988), l'urée surestime d'environ 8% l'eau corporelle totale chez le chevreau alimenté au lait (Schmidely et al, 1990 (Schmidely et al, 1990). L'espace de diffusion de l'urée EU dans l'organisme a été assimilé à un système à 2 compartiments : un central C (volume VC) et un périphérique P (VP).…”

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Analyse compartimentale du biais de l'estimation de l'eau corporelle par l'espace de diffusion de l'urée chez le chevreau alimenté au lait

Schmidely¹,

Bas²,

Rouzeau³

1992

Ann. Zootech.

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“…Introduction -L'urée injectée par voie iv a été utilisée pour estimer l'eau du corps vide (ECV) chez le jeune poulain sous la mère (Geerken et al, 1988 …”

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