The effect of lowering the ambient temperature on the metabolism of the new‐born pig

McCance, R. A.; Widdowson, E. M.

doi:10.1113/jphysiol.1959.sp006227

Cited by 79 publications

(47 citation statements)

References 23 publications

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“…Subsequently, it would be expected to decrease as carbohydrate reserves are used, so that a decrease of 0 05 has been assumed in Table 1 (Shelley, 1961(Shelley, , 1964. The amounts in liver and skeletal muscle are quantitatively the most important, but in all three species about 90% of liver glycogen and only 60% or less of muscle glycogen can be mobilized during the first day after birth (McCance & Widdowson, 1959;Shelley, 1961Shelley, , 1964Alexander, 1962c;Anderson & Wahlstrom, 1970;Elliot & Lodge, 1977). The calculations summarized in Table 3 reveal two noteworthy points.…”

Section: Substrates For Heat Productionmentioning

confidence: 99%

A Comparison of Energy Metabolism in the New‐born Infant, Piglet and Lamb

1986

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Characteristics of energy metabolism in the new‐born infant, piglet and lamb have been compared quantitatively in order to assess how the constraints imposed by the availabilities of energy substrates in body reserves and colostrum differ between species and affect the new‐born's well being during the first day after birth. Three air temperature ranges, described as thermoneutral (32‐38 °C), moderate (18‐26 °C) and cold (0‐10 °C) and representing the usual birth environments of infants, piglets and lambs, respectively, have been considered. The analysis revealed the following noteworthy points. Carbohydrate and lipid are the major energy substrates for heat production because protein catabolism is minimal during the first day after birth in all three species. The availability of carbohydrate determines how long the new‐born can avoid hypoglycaemia, which threatens well being because it leads to hypothermia or compromised cerebral function, but lipid availability can affect the periods for which the carbohydrate can last. Thus, in unfed piglets and lambs the available reserves of liver and skeletal muscle glycogen (g/kg body weight) are similar in normal (n.) and growth retarded (g.r.) individuals, but glycogen exhaustion occurs earlier in g.r. new‐borns because a reduced lipid availability in them increases their dependence on carbohydrate. In contrast, lipid energy is plentiful in g.r., preterm (p.) and n. infants, so that the faster depletion of glycogen in g.r./p. than in n. individuals is primarily due to a restricted prenatal glycogen deposition in the former. The usual colostrum intakes of n. infants are very low during the first day, but their body reserves can supply the required energy, the major source of carbohydrate being liver glycogen. However, g.r./p. infants require supplementary feeding, the choice of feed being determined by factors such as the intakes the infants can achieve, the carbohydrate content of the feed and the need to ensure a balanced supply of minerals, electrolytes and other substances. In their usual birth environments piglets and lambs, whether growth retarded or not, require colostrum to avoid hypothermia during the first day. The colostrum of both species is rich in lipid, which corrects any deficit in the new‐born and thus extends the availability of glycogen, but at the usual colostrum intakes the amounts of lactose can provide sufficient carbohydrate energy for only about half a day. Piglets and lambs, even when fed fully, are therefore obliged to call on their body glycogen reserves in order to make up the difference. After the first day in all three species milk must rapidly become the only source of carbohydrate, lipid and protein. It is suggested that despite differences between them, the piglet or lamb could prove to be useful animal models of the infant's metabolism, but only if the experimental conditions are chosen carefully.

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Section: Substrates For Heat Productionmentioning

confidence: 99%

A Comparison of Energy Metabolism in the New‐born Infant, Piglet and Lamb

1986

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“…6): values of 30-40 mg/g had been observed in lambs just over half way through gestation, comparable to the cardiac glycogen in human foetuses in the first half of gestation (Villee, 1954). There are no quantitative estimates of cardiac carbohydrate in foetuses of other species, but new-born rats, which are relatively immature at birth, have 22-31 mg/g, new-born rabbits have 5-13 mg/g, and the exceptionally mature new-born guinea-pig has only 4-5 mg/g , similar to the level in the infant and adult monkeys and in other adult mammals (Cruickshank, 1936); new-born piglets have 15 mg/g (McCance & Widdowson, 1959) and new-born kittens have 11-14 mg/g (Shelley, unpublished).…”

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confidence: 95%

“…In another ungulate, the pig, foetal liver glycogen also begins to rise at 105-120 days gestation age (Mendel & Leavenworth, 1907;Aron, 1922), though since the gestation period is only 120 days, the rise occurs nearer term than in the lambs; the livers of newborn piglets contain 85 mg/g (McCance & Widdowson, 1959). Liver glycogen also rises late in gestation in rodents; in rats the rise occurs in the last fifth of gestation to a maximum of 106 mg/g at term (Corey, 1935 Jacquot, 1955), in rabbits in the last quarter to about 40 mg/g at term (Lochhead & Cramer, 1908;Snyder & Hoskins, 1928;Szendi, 1936;Jost & Jacquot, 1955) and in guinea-pigs during the last fifth to about 30 mg/g at term (Aron, 1922;Hard, Reynolds & Winbury, 1944).…”

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confidence: 99%

Blood sugars and tissue carbohydrate in foetal and infant lambs and rhesus monkeys

Shelley¹

1960

The Journal of Physiology

101

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During a previous investigation (Dawes, Mott & Shelley, 1959), the carbohydrate content of various tissues from foetal lambs just over halfway through gestation was determined for comparison with that of foetuses near term. The carbohydrate concentrations in the heart, liver, lungs and skeletal muscle were very different in the two groups, and the work has now been extended to include lambs of earlier and intermediate ages so as to follow the changes in carbohydrate concentration throughout the last two-thirds of gestation. Large amounts of glycogen were laid down towards the end of gestation, not only in the liver but also in skeletal muscle, and measurements of tissue carbohydrate have been made in new-born and infant lambs of up to 17 days old so as to determine its fate after birth. The lamb is relatively mature at birth and exceptionally active, and the results suggest that both the liver and the skeletal muscle carbohydrate constitute carbohydrate reserves for use in the first 24 hr of extrauterine life. The rhesus monkey is also fairly mature at birth, and estimates of tissue carbohydrate have been obtained in this species during the last third of gestation and in infant monkeys 8-15 days old. This paper compares the results obtained on lambs and monkeys with those in other species and discusses their possible significance. A preliminary account of this work has already been published (Shelley, 1960). METHODS Experimental procedure and animal8Foetal lambs. Observations have been made on forty-six foetal lambs (gestation age 58-146 days) from twenty-four cross-bred ewes; eight ewes carried single lambs, eleven carried twins, four carried triplets and one ewe carried quadruplets and developed signs of pregnancy toxaemia a few days before the experiment.The lambs were delivered by Caesarean section under chloralose or pentobarbitone anaesthesia and were left attached to the ewe, care being taken to avoid stretching or compressing the umbilical cord. A foetal blood sample (0-8 ml.) was taken into a 1 ml. syringe, the dead space of which had been filled with 0-4 % heparin in sodium fluoride

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“…The fact that older (and larger) mice survive the cold may be attributed to the lower rate of cooling in an animal with a higher volume/surface ratio and to increased reserves. The young mice that fail to survive the cold perhaps resemble in their metabolism the new-born pigs studied by McCance and Widdowson [1959]. Their work suggests that the ionic and nitrogen metabolism of cold-stressed mice would repay study.…”

Section: Discussionmentioning

confidence: 99%

Mortality, Growth and Liver Glycogen in Young Mice Exposed to Cold

1960

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Mice of four strains were reared at 21°C. and then transferred to ‐3°C., in individual cages with nesting material. Controls were kept in similar conditions at 21°C. Many of the mice of two A strains died when stressed by cold at the age of 3 weeks, but none at 5 or 12 weeks. Many C57BL and GFF mice died when stressed at 5 weeks. Death usually occurred during the first 3 days, often on the first day. All stressed mice lost weight, especially in the first 2 days; if they survived, they made up the lost weight but they grew more slowly than the controls at all stages. Mice reared at ‐3°C. and stressed in that temperature when 3 weeks old had a lower mortality than those transferred from 21°C., and survivors did not lose weight. Mice reared at ‐3°C. and transferred to 21°C. at 3 weeks, although initially lighter, grew quickly and after 1 week were as heavy as the controls. Three‐week‐old mice stressed at ‐3°C. lost liver glycogen quickly whether they had been reared at 21°C. or ‐3°C. This was not due to a failure to eat, and there was no evidence that death resulted from inability to mobilize carbohydrate reserves.

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The effect of lowering the ambient temperature on the metabolism of the new‐born pig

Cited by 79 publications

References 23 publications

A Comparison of Energy Metabolism in the New‐born Infant, Piglet and Lamb

A Comparison of Energy Metabolism in the New‐born Infant, Piglet and Lamb

Blood sugars and tissue carbohydrate in foetal and infant lambs and rhesus monkeys

Mortality, Growth and Liver Glycogen in Young Mice Exposed to Cold

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