Changes during eating in oxygen consumption, cardiac function and body fluids of sheep

Christopherson, R. J.; Webster, A. J. F.

doi:10.1113/jphysiol.1972.sp009760

Cited by 43 publications

(26 citation statements)

References 18 publications

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“…Fasting plus water restriction in the warm environment resulted in an increase of blood haemoglobin after 24 h of treatment (P < 0.05). The blood haemoglobin values (11.58-13.22 g dL -1 ) in the present investigation were higher than values (8-9 g dL -1 ) reported by (Christopherson and Webster 1972) for mature ewes. The difference could have been a result of age and nutritional conditions in the two studies.…”

Section: Haemoglobincontrasting

confidence: 55%

“…The present treatments resulted in only 3.4-7.0% losses of plasma volume. These were less than data from Degen and Kam (1992), which showed that rams lost 41.7% plasma volume after deprivation of water for 4 d. These differences may be due to different methods of assay and calculation, ability of adaptation to dehydration as inherited differences, or due to feeding conditions (Christopherson and Webster 1972).…”

Section: Plasma Volumecontrasting

confidence: 39%

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Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep

Li¹,

Christopherson²,

Cosgrove³

2000

Can. J. Anim. Sci.

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. 2000. Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep. Can. J. Anim. Sci. 80: 97-104. The hypothesis that water restriction reduces metabolic rate and contributes to energy conservation of sheep, and induces changes in blood parameters was tested. Four of eight adult sheep were housed in either a warm (24.8 ± 1.5°C) or cold (0.4 ± 1.2°C) environment and fed a diet of alfalfa pellets at 1.2 × maintenance. Each sheep was fasted with or without water according to a crossover design. Average heat production (HP) and rectal temperature (Tr) were higher (P < 0.05) in the cold than in the warm. Fasting decreased HP and Tr (P < 0.05). Water restriction had no additional effect on HP and Tr. Fasting and fasting plus water restriction influenced plasma osmolality and creatinine concentration. Plasma creatinine concentration was lower (P < 0.01) and haemoglobin (Hb) concentration higher in the cold than in the warm environment. Hb concentration was increased with water restriction (P < 0.01) in the warm environment. Plasma cortisol concentration was altered by fasting. Packed cell volume (PCV) in blood, plasma volume and plasma aldosterone were not affected by treatments. The results suggest that water restriction, per se, for 3 d does not suppress metabolic rate in sheep below that resulting from fasting alone. Chaque mouton était ensuite mis au jeûne pendant trois jours, avec ou sans eau, selon un dispositif avec permutation des traitements. La production de chaleur moyenne (PCh) et la température rectale (Tr) étaient plus élevées (P < 0,05) dans l'ambiance froide que dans la chaude. Le jeûne, seul ou avec restriction d'abreuvement, influait sur l'osmolarité et sur la concentration de créatinine du plasma. En outre, ce dernier paramètre était plus bas (P < 0,01) dans l'ambiance froide, alors que l'inverse s'observait pour la concentration d'hémoglobine (Hb) dans le sang. La concentration de Hb augmentait, quand l'eau était rationnée (P < 0,01), dans l'ambiance chaude. La concentration plasmatique de cortisol était modifiée par suite du jeûne de solide. L'hématocrite (HCT), le volume de plasma et la concentration d'aldostérone plasmatique ne manifestaient pas de réaction aux traitements. Il ressort des observations que à lui seul le rationnement de l'eau pendant 3 jours n'a pas plus d'effet négatif sur la thermogenèse chez le mouton que le jeûne solide seul.Mots clés: Thermogenèse, mouton, température, rationnement de l'eau Changes in the thermal environment induce a variety of physiological responses in animals (Christopherson and Kennedy 1983). Metabolic rate is increased during cold exposure in sheep (Christensen et al. 1990), and also during the period of heat stress in cattle (Miaron et al. 1995). Therefore, energy requirements of animals are increased in a cold environment and also during acute heat stress (Miaron et al. 1995). However, there is evidence that a portion of increased energy expenditure in response to environment may exceed that which...

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Section: Haemoglobincontrasting

confidence: 55%

Section: Plasma Volumecontrasting

confidence: 39%

Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep

Li¹,

Christopherson²,

Cosgrove³

2000

Can. J. Anim. Sci.

Self Cite

View full text Add to dashboard Cite

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“…The 11 % reduction in plasma volume was similar to values for reductions in plasma volume and thiosulphate space reported by others (Ternouth 1968;Blair-West and Brook 1969;Christopherson and Webster 1972). Maximum haematocrit in the present study coincided in each case with the occurrence of minimum plasma volume.…”

Section: Discussionsupporting

confidence: 72%

“…The physiology of sheep is extensively altered when they start to eat dry rations (Blair-West and Brook 1969;Christopherson and Webster 1972;Dooley et al 1972). Several of the observed changes may be related directly to the need of the sheep under these feeding conditions to produce large volumes of saliva rapidly to facilitate swallowing.…”

Section: Introductionmentioning

confidence: 99%

Changes in Plasma Volume and Haematocrit in Intact and Splenectomized Sheep During Feeding

Dooley¹,

Williams²

1976

Aust. Jnl. Of Bio. Sci.

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Changes in jugular haematocrit during daily 2-h feeding periods in trained sheep with and without spleens were compared with changes in the concentration of the plasma tracer radio-iodinated human serum albumin. Jugular haematocrit was increased by 16 % in intact sheep and 9 % in splenectomized sheep 20 min after they started to eat dry rations.The dilution of tracer in plasma, studied after mixing in the vascular system had been completed, showed four phases. Phase 1 was the rate of removal of tracer in the period before eating began. Phase 2 was the sudden increase in plasma radioactivity that occurred in the first 20 min of eating, indicating a loss of plasma from the circulation. Phase 3 was the decrease in tracer concentration during the remaining feeding period and phase 4 was a post-feeding phase, characterized by a slower rate of decrease of tracer than during phase 3, implying that there was significant recycling of tracer during this phase.The sudden increase in plasma radioactivity, initiated by the onset of feeding, represented a reduction in plasma volume of 10-12 %. Minimum plasma volume coincided with peak haematocrit values. The reduced plasma volume accounted for the increased haematocrit in splenectomized sheep, but only accounted for about half of the increase in intact sheep. The residual increase in haematocrit in intact sheep was most likely the result of splenic contraction.

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“…The events that take place during and immediately after the act of eating, in particular the passage of plasma fluid to extracellular space and then to the digestive tract (Bailey 1961;Stacy and Warner [1966] cited in Christopherson and Webster [1972]) and the increase of osmotic pressure (Stacy and Warner [1966] cited in Christopherson and Webster [1972]; Ternouth 1968) could possibly explain a parallel movement of ALB from intravascular to extravascular space, to prevent abrupt and dangerous variations of oncotic pressure. Since the permeability of vascular walls to ALB is low, movement of ALB probably occurs mainly across the large pores of the liver sinusoids.…”

Section: Albumin Globulins and Total Proteinmentioning

confidence: 99%

Daily variation in blood enzymes and metabolites in ewes under three levels of feed intake

Caldeira¹,

Almeida²,

Santos³

et al. 1999

Can. J. Anim. Sci.

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. 1999. Daily variation in blood enzymes and metabolites in ewes under three levels of feed intake. Can. J. Anim. Sci. 79: 157-164. Daily variations in the concentration of albumin, creatinine, non-esterified fatty acids, globulins, glucose, total lipids, total protein, triglycerides, urea, β-hydroxybutyrate, and in the activity of alkaline phosphatases, aspartate aminotransferase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, isocitrate dehydrogenase and pyruvate kinase were evaluated in the serum or plasma of ewes fed 30, 100 and 200% of theoretical maintenance energy requirements. A daily profile was observed in almost all variables, which may be of importance when interpreting data for these blood indicators. Daily variations were found even for albumin and total protein serum concentrations, showing a significant decrease of their levels after the meal. In order to maximize the diagnostic value of these indicators, the most suitable times for blood collection seem to be 16 h after the meal and (or) just before the meal. Collection 16 h after the meal apparently allows the characterisation of a relatively steady metabolic state, intermediate between the effects of food intake and the final phase of the intensification of body reserve mobilization. Collection just before the meal will give a good indication of the level of activity of those mobilization mechanisms. La variation quotidienne d'albumine, créatinine, acides gras non estérifiés, globulines, glucose, lipides totaux, protéines totales, triglycérides, urée, β-hydroxybutyrate, phosphatases alcalines, aspartate aminotransférase, glucose-6-phosphate déshydrogénase, glutamate déshydrogénase, isocitrate déshydrogénase, pyruvate kinase fut évaluée dans le sérum ou le plasma des brebis ayant reçu dans l'alimentation 30 %, 100 % et 200 % des besoins énergétiques d'entretien théoriques. Nous avons observé, dans presque toutes les variables, un type de profile quotidien susceptible d'influencer l'interprétation de ces indicateurs sanguins. Des variations quotidiennes ont été trouvées même pour des concentrations d'albumine et de protéine totale dans le sérum, montrant une diminution significative de leurs niveaux après le repas. Pour maximiser la valeur diagnostique de ces indicateurs, les moments les plus appropriés pour faire la prise de sang semblent être 16 heures après le repas et (ou) juste avant le repas. La prise de sang 16 heures après le repas permet de caractériser un état métabolique relativement constant, intermédiaire entre les effets proches de l'ingestion et la phase finale d'intensification de la mobilisation des réserves corporelles. La prise de sang juste avant le repas donne une bonne image du niveau d'activité de ces mécanismes de mobilisation.

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Changes during eating in oxygen consumption, cardiac function and body fluids of sheep

Cited by 43 publications

References 18 publications

Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep

Effect of water restriction and environmental temperatures on metabolic rate and physiological parameters in sheep

Changes in Plasma Volume and Haematocrit in Intact and Splenectomized Sheep During Feeding

Daily variation in blood enzymes and metabolites in ewes under three levels of feed intake

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