Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T04:39:23.645Z Has data issue: false hasContentIssue false
  • English
  • Français

Nutritional effects on foetal growth

Published online by Cambridge University Press:  18 August 2016

J. J. Robinson ,
K. D. Sinclair  and
T. G. McEvoy
J. J. Robinson
Affiliation:
Animal Biology Division, Scottish Agricultural College, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
K. D. Sinclair
Affiliation:
Animal Biology Division, Scottish Agricultural College, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
T. G. McEvoy
Affiliation:
Animal Biology Division, Scottish Agricultural College, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA
Get access

Abstract

The emphasis in nutritional studies on foetal growth has now moved from the last trimester of pregnancy, when most of the increase in foetal size takes place, to earlier stages of pregnancy that coincide with foetal organogenesis and tissue hyperplasia. At these stages absolute nutrient requirements for foetal growth are small but foetal metabolic activity and specific growth rate are high. It is thus a time when nutrient supply interacts with maternal factors such as size, body condition and degree of maturity to influence placental growth and set the subsequent pattern of nutrient partitioning between the gravid uterus and maternal body.

Throughout pregnancy the maternal diet controls foetal growth both directly, by supplying essential nutrients and indirectly, by altering the expression of the maternal and foetal endocrine mechanisms that regulate the uptake and utilization of these nutrients by the conceptus. Nutritional effects on the endocrine environment of the embryo during the early stages of cell division can alter the subsequent foetal growth trajectory and size at birth; so too can current in vitro systems for oocyte maturation and embryo culture up to the blastocyst stage. There is increasing evidence that subtle alterations in nutrient supply during critical periods of embryonic and foetal life can impart a legacy of growth and developmental changes that affect neonatal survival and adult performance. Identifying the specific nutrients that programme these effects and understanding their mode of action should provide new management strategies for ensuring that nutritional regimens from oocyte to newborn are such that they maximize neonatal viability and enable animals to express their true genetic potential for production.

Keywords

foetal growthnutrition
Type
Research Article
Information
Animal Science , Volume 68 , Issue 2 , March 1999 , pp. 315 - 331
Copyright
Copyright © British Society of Animal Science 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anthony, R. V., Pratt, S. L., Liang, R. and Holland, M. D. 1995. Placental-fetal hormonal interactions: impact on fetal growth. Journal of Animal Science 73: 1861–1871.Google Scholar
Arthur, J. R. 1991. The role of selenium in thyroid hormone metabolism. Canadian Journal of Physiology and Pharmacology 69: 1648–1652.Google Scholar
Ashworth, C. J. 1991. Effect of pre-mating nutritional status and post-mating progesterone supplementation on embryo survival and conceptus growth in gilts. Animal Reproduction Science 26: 311–321.CrossRefGoogle Scholar
Ashworth, C. J. 1995. Maternal and conceptus factors affecting histotrophic nutrition and survival of embryos. Livestock Production Science 44: 99–105.Google Scholar
Barker, D. J. P., Gluckman, P. D., Godfrey, K. M., Harding, J. E., Owens, J. A. and Robinson, J. S. 1993. Fetal nutrition and cardiovascular disease in adult life. Lancet 341: 938–941.Google Scholar
Bassett, J. M. 1991. Current perspectives on placental development and its integration with fetal growth. Proceedings of the Nutrition Society 50: 311–319.CrossRefGoogle ScholarPubMed
Bassett, J. M. 1995. Glucose and fetal growth derangement. In Fetus and neonate, volume 111, growth (ed. Hanson, M. A., Spencer, J. A. D. and Rodeck, C. H.), pp. 223–254. Cambridge University Press, Cambridge.Google Scholar
Bassett, J. M. and Hanson, C. 1998. Catecholamines inhibit growth in fetal sheep in the absence of hypoxemia. American Journal of Physiology 274: R1536-R1545.Google Scholar
Battaglia, F. C. 1992. New concepts in fetal and placental amino acid metabolism. Journal of Animal Science 70: 3258–3263.CrossRefGoogle ScholarPubMed
Bell, A. W. and Bauman, D. E. 1997. Adaptations of glucose metabolism during pregnancy and lactation. Journal of Mammary Gland Biology and Neoplasia 2: 265–278.CrossRefGoogle ScholarPubMed
Bell, A. W., Kennaugh, J. M., Battaglia, F.C. and Meschia, G. 1989. Uptake of amino acids and ammonia at mid-gestation by the fetal lamb. Quarterly Journal of Experimental Physiology 74: 635–643.Google Scholar
Berthon, D., Herpin, P., Duchamp, C., Dauncey, M. J. and Dividich, J. 1993. Modification of thermogenic capacity in neonatal pigs by changes in thyroid status during late gestation. Journal of Developmental Physiology 13: 253–261.Google Scholar
Black, J. L. 1983. Growth and development of lambs. In Sheep production (ed. Haresign, W.), pp. 21–58. Butterworths, London.Google Scholar
Borwick, S. C., Rhind, S. M., McMillan, S. R. and Racey, P. A. 1997. Effect of undernutrition of ewes from the time of mating on fetal ovarian development in mid gestation. Reproduction, Fertility and Development 9: 711–715.CrossRefGoogle ScholarPubMed
Butterstein, G. M., Angerosa, J. A., Keuhn, J. S. and Castracane, V. D. 1998. Serum leptin changes throughout rat pregnancy. Biology of Reproduction 58: (supplement 1) 121.Google Scholar
Cann, C. H., Fairclough, R. J., Sutton, R. and Gow, C. B. 1997. Endometrial expression of mRNA encoding insulinlike growth factors I and II and IGF-binding proteins 1 and 2 in early pregnant ewes. Journal of Reproduction and Fertility 111: 7–13.CrossRefGoogle ScholarPubMed
Caple, I. W. and Nugent, G. F. 1982. Relationship between plasma thyroxine concentrations and the responses of newborn lambs to hypothermia. Proceedings of the Australian Society of Animal Production 94: 657.Google Scholar
Care, A. D. and Barlet, J. P. 1995. Endocrinological factors in the control of skeletal growth of fetal and neonatal ruminant animals. In Ruminant physiology: digestion, growth and reproduction (ed. Englehardt, W. v., Leonhard-Marek, S., Brewes, G. and Giesecke, D.), proceedings of the eighth international symposium on ruminant physiology, pp. 485–499. Ferdinand Enke Verlag, Stuttgart.Google Scholar
Carolan, C., McEvoy, T. G., Staines, M. E., Sinclair, K. D., Robinson, J. J. and Broadbent, P. J. 1998. Variation in the expression of fetal oversize in day 125 ovine fetuses following transfer of in vitro cultured embryos. Theriogenology 49: 229.Google Scholar
Chard, T. 1994. Insulin-like growth factors and their binding proteins in the control of human fetal growth. In Early fetal growth and development (ed. Ward, R. H. T., Smith, S.K. and Donnai, D.), pp. 293–308. RCOG Press, London.Google Scholar
Clarke, L., Heasman, L., Juniper, D. T. and Symonds, M. E. 1998a. Maternal nutrition in early-mid gestation and placental size in sheep. British Journal of Nutrition 79: 359–364.Google Scholar
Clarke, L., Heasman, L. and Symonds, M. E. 1998b. Influence of maternal dexamethasone administration on thermoregulation in lambs delivered by caesarean section. Journal of Endocrinology 156: 307–314.CrossRefGoogle ScholarPubMed
Cohen, B., Novick, D. and Rubinstein, M. 1996. Modulation of insulin activities by leptin. Science 274: 1185–1188.CrossRefGoogle ScholarPubMed
Crowe, C., Bennet, L. and Hanson, M. A. 1995. Blood pressure and cardiovascular reflex development in fetal sheep. Relation to hypoxaemia, weight, and blood glucose. Reproduction, Fertility and Development 7: 553–558.CrossRefGoogle ScholarPubMed
Dean, W., Bowden, L., Aitchison, A., Klose, J., Moore, T., Meneses, J. J., Reik, W. and Feil, R. 1998. Altered imprinted gene methylation and expression in completely ES cell-derived mouse fetuses: association with aberrant phenotypes. Development 125: 2273–2282.CrossRefGoogle ScholarPubMed
Dodic, M., May, C. N., Wintour, E. M. and Coghlan, J. P. 1998. An early prenatal exposure to excess glucocorticoid leads to hypertensive offspring in sheep. Clinical Science 94: 149–155.Google Scholar
Donald, G. E., Langlands, J. P., Bowles, J. E. and Smith, A. J. 1994. Subclinical selenium insufficiency. 6. Thermoregulatory ability of perinatal lambs born to ewes supplemented with selenium and iodine. Australian Journal of Experimental Agriculture 34: 19–24.Google Scholar
Dwyer, C. M., Madgwick, A. J. A., Ward, S. S. and Stickland, N. C. 1995. Effect of maternal undernutrition in early gestation on the development of fetal myofibres in the guinea-pig. Reproduction, Fertility and Development 7: 1285–1292.Google Scholar
Dwyer, C. M. and Stickland, N. C. 1994. Supplementation of a restricted maternal diet with protein or carbohydrate alone prevents a reduction in fetal muscle fibre number in the guinea-pig. British Journal of Nutrition 72:173–180.CrossRefGoogle ScholarPubMed
Dwyer, C. M., Stickland, N. C. and Fletcher, J. M. 1994. The influence of maternal nutrition on muscle fiber number development in the porcine fetus and on subsequent postnatal growth. Journal of Animal Science 72: 911–917.Google Scholar
Edwards, S. A. 1998. Nutrition of the rearing gilt and sow. In Progress in pig science (ed. Wiseman, J., Varley, M. A. and Chadwick, J. P.), pp. 361–382. oNottingham University Press.Google Scholar
Ehrhardt, R. A. and Bell, A. W. 1995. Growth and metabolism of the ovine placenta during mid-gestation. Placenta 16: 727–741.Google Scholar
Farin, P. W. and Farin, C. E. 1997. Perspectives on large calves following transfer of embryos produced in vitro . Embryo Transfer Newsletter 15:15–19.Google Scholar
Ferguson, E. M. and Leese, H. J. 1998. Triglyceride and protein content of early cattle embryos. Journal of Reproduction and Fertility, Abstract Series 21: 23.Google Scholar
Fisher, C. E. J. and MacPherson, A. 1991. Effect of cobalt deficiency in the pregnant ewe on reproductive performance and lamb viability. Research in Veterinary Science 50: 319–327.Google Scholar
Fowden, A. L. 1995. Endocrine regulation of fetal growth. Reproduction, Fertility and Development 7: 351–363.Google Scholar
Fowden, A. L., Li, J. and Forhead, A. J. 1998. Glucocorticoids and the preparation for life after birth: are there long-term consequences of the life insurance? Proceedings of the Nutrition Society 57:113–122.Google Scholar
Fowden, A. L., Mij o vie, J. and Silver, M. 1993. The effects of cortisol on hepatic and renal gluconeogenic enzyme activities in the sheep fetus during late gestation. Journal of Endocrinology 137: 213–222.CrossRefGoogle ScholarPubMed
Fowden, A. L., Szemere, J., Hughes, P., Gilmore, R. S. and Forhead, A. J. 1996. The effects of cortisol on the growth rate of the sheep fetus during late gestation. Journal of Endocrinology 151: 97–105.Google Scholar
Garrett, J. E., Geisert, R. D., Zavy, M. T. and Morgan, G. L. 1988. Evidence for maternal regulation of early conceptus growth and development in beef cattle. Journal of Reproduction and Fertility 84: 437–447.Google Scholar
Gerrard, D. E., Grant, A. L., Anderson, D.B., Lemenager, R. P. and Judge, M. D. 1995. In-vivo analysis of serum-borne growth factors in developing co-twinned fetuses. Journal of Animal Science 73:1689–1693.Google Scholar
Gill, J. W., Hosking, B. J., Hoist, P. J., Fogarty, N. M., Hopkins, D. L. and Egan, A. R. 1998. Genotype differences in responses of growth and carcass characteristics to the intrauterine cohabitant phenomenon in twin lambs. Animal Science 66: 375–382.Google Scholar
Gluckman, P. D. and Harding, J. E. 1997. The physiology and pathophysiology of intrauterine growth retardation. Hormone Research 48: (supplement 1) 11–16.Google Scholar
Godfrey, K. and Robinson, S. 1998. Maternal nutrition, placental growth and fetal programming. Proceedings of the Nutrition Society 57: 105–111.Google Scholar
Gunn, R. G., Sim, D. A. and Hunter, E.A. 1995. Effects of nutrition in utero and in early life on the subsequent lifetime reproductive performance of Scottish Blackface ewes in two management systems. Animal Science 60: 223–230.Google Scholar
Gutzwiller, A. 1993. The effect of a diet containing cyanogenetic glycosides on the selenium status and the thyroid function of sheep. Animal Production 57: 415–419.Google Scholar
Harding, J. E., Liu, L., Evans, P. C. and Gluckman, P. D. 1994. Insulin-like growth factor 1 alters feto-placental protein and carbohydrate metabolism in fetal sheep. Endocrinology 134: 1509–1514.CrossRefGoogle ScholarPubMed
Heasman, L., Clarke, L., Firth, K., Stephenson, T. and Symonds, M. E. 1998. Influence of restricted maternal nutrition in early to mid gestation on placental and fetal development at term in sheep. Paediatric Research 44: 546–551.CrossRefGoogle ScholarPubMed
Hoggard, N., Hunter, L., Duncan, J. S., Williams, L. M., Trayhurn, P. and Mercer, J. G. 1997. Leptin and leptin receptor mRNA and protein expression in the murine fetus and placenta. Proceedings of the National Academy of Sciences USA 94: 11073–11078.Google Scholar
Holm, P., Walker, S. K. and Seamark, R. F. 1996. Embryo viability, duration of gestation and birthweight in sheep after transfer of in vitro matured and in vitro fertilized zygotes cultured in vitro or in vivo . Journal of Reproduction and Fertility 107:175–181.Google Scholar
Houseknecht, K. L., Baile, C.A., Matteri, R. L. and Spurlock, M. E. 1998. The biology of leptin: a review. Journal of Animal Science 76: 1405–1420.Google Scholar
Hutchings, N. J. 1997. Estimating the metabolizable energy requirement for pregnancy in sheep. Animal Science 64: 463–467.CrossRefGoogle Scholar
Jones, J. I. and Clemmons, D. R. 1995. Insulin-like growth factors and their binding proteins: biological actions. Endocrine Reviews 16: 3–34.Google Scholar
Kelly, R. W. 1992. Nutrition and placental development. Proceedings of the Nutrition Society of Australia 17: 203–211.Google Scholar
Kleemann, D. O., Walker, S. K. and Seamark, R. F. 1994. Enhanced fetal growth in sheep administered progesterone during the first three days of pregnancy. Journal of Reproduction and Fertility 102: 411–417.Google Scholar
Kruip, Th. A. M. and Daas, J. H. G. den. 1997. In vitro produced and cloned embryos: effects on pregnancy, parturition and offspring. Theriogenology 47: 43–52.Google Scholar
Langley-Evans, S.C, Phillips, G. J., Benediktsson, R., Gardner, D. S., Edwards, C. R. W., Jackson, A. A. and Seckl, J. R. 1996. Protein intake in pregnancy, placental glucocorticoid metabolism and the programming of hypertension in the rat. Placenta 17: 169–172.Google Scholar
Ledgard, A. M., Hodgkinson, S. C., Tervit, H. R. and Peterson, A. J. 1995. The novel insulin-like growth factor binding proteins (IGFBP) in sheep uterine luminal fluid (ULF) are proteolytic fragments of IGFBP3: effect of progesterone. Journal of Reproduction and Fertility, Abstract Series 15: 35–36.Google Scholar
Lee, C. Y., Green, M. L., Summer, R. C. M. and Summer, F. A. 1998. Proteolysis of insulin-like growth factor-binding proteins (IGFBP’s) within the pig uterine lumen associated with peri-implantation conceptus development. Journal of Reproduction and Fertility 112: 369–377.Google Scholar
Leighton, P. A., Saam, J. R., Ingram, R. S. and Tilghman, S. M. 1996. Genomie imprinting in mice: its function and mechanism. Biology of Reproduction 54: 273–278.Google Scholar
Leury, B. J., Bird, A. R., Chandler, K. D. and Bell, A. W. 1990. Glucose partitioning in the pregnant ewe: effects of undernutrition and exercise. British Journal of Nutrition 64: 449–462.Google Scholar
Li, J., Saunders, J. C., Gilmour, R. S., Silver, M. and Fowden, A. L. 1993. Insulin-like growth factor-II messenger ribonucleic acid expression in fetal tissues of the sheep during late gestation: effects of cortisol. Endocrinology 132: 2083–2089.Google Scholar
Lippert, M., Milne, J. A. and Rüssel, A.J.F. 1983. Effect of mid-pregnancy supplementation on hill-ewe performance. Animal Production 36: 543 (abstr.).Google Scholar
McCoard, S. A., Peterson, S. W., McNabb, W. C., Harris, P. M. and McCutcheon, S. N. 1997. Maternal constraint influences muscle fibre development in fetal lambs. Reproduction, Fertility and Development 9: 675–681.Google Scholar
McCrabb, G. J., Egan, A. R. and Hosking, B. J. 1992. Maternal under nutrition during mid-pregnancy in sheep: variable effects on placental growth. Journal of Agricultural Science, Cambridge 118:127–132.Google Scholar
McEvoy, T. G., Robinson, J. J., Aitken, R. P., Findlay, P. A., Palmer, R. M. and Robertson, I. S. 1995a. Dietary-induced suppression of pre-ovulatory progesterone concentrations in superovulated ewes impairs the subsequent in vivo and in vitro development of their ova. Animal Reproduction Science 39: 89–107.Google Scholar
McEvoy, T. G., Robinson, J. J., Aitken, R. P., Findlay, P. A. and Robertson, I. S. 1997. Dietary excesses of urea influence the viability and metabolism of preimplantation sheep embryos and may affect fetal growth among survivors. Animal Reproduction Science 47: 71–90.Google Scholar
McEvoy, T. G., Robinson, J. J., Findlay, P. A. and Madibela, O. R. 1995b. Ammonia concentrations during in vitro culture are elevated by human serum and somatic cells. Journal of Reproduction and Fertility, Abstract Series 15: 72–73.Google Scholar
McEvoy, T. G., Sinclair, K. D., Goodhand, K. L., Broadbent, P. J. and Robinson, J. J. 1998. Post-natal development of Simmental calves derived from in vivo or in vitro embryos. In Gametes: development and function (ed. Lauria, A., Gendolfi, F., Enne, G. and Gianoroli, L.), p. 573. Serono Symposia. Tabloid S.r.L, Rome.Google Scholar
McNeill, D. M., Slepetis, R., Ehrhardt, R. A., Smith, D. M. and Bell, A. W. 1997. Protein requirements of sheep in late pregnancy: partitioning of nitrogen between gravid uterus and maternal tissues. Journal of Animal Science 75: 809–816.Google Scholar
Mahan, D. C. and Vallet, J. L. 1997. Vitamin and mineral transfer during fetal development and the early postnatal period in pigs. Journal of Animal Science 75: 2731–2738.Google Scholar
Mann, G. E., Mann, S. J. and Lamming, G. E. 1996. The inter-relationships between the maternal hormone environment and the embryo during the early stages of pregnancy in the cow. Journal of Reproduction and Fertility, Abstract Series 17: 21.Google Scholar
Masters, D. G., Keen, C. L., Lönnerdal, B. and Hurley, L. S. 1983. Zinc deficiency teratogenicity: the protective role of maternal tissue catabolism. Journal of Nutrition 113: 905–912.CrossRefGoogle ScholarPubMed
Masters, D. G., Stewart, C. A., Mata, G. and Adams, N. R. 1996. Responses in wool and live weight when different sources of dietary protein are given to pregnant and lactating ewes. Animal Science 62:497–506.Google Scholar
Maxfield, E. K., Sinclair, K. D., Broadbent, P. J., McEvoy, T. G., Robinson, J. J. and Maltin, C.A. 1998a. Short term culture of ovine embryos modifies fetal myogenesis. American Journal of Physiology 274: E1121-E1123.Google Scholar
Maxfield, E. K., Sinclair, K. D., Dunne, L. D., Broadbent, P. J., Robinson, J. J., Stewart, E., Kyle, D. G. and Maltin, C.A. 1998b. Temporary exposure of ovine embryos to an advanced uterine environment does not affect fetal weight but alters fetal muscle development. Biology of Reproduction 59: 321–325.Google Scholar
Meat and Livestock Commission. 1983. Feeding the ewe. MLC Sheep Improvement Services, Milton Keynes.Google Scholar
Mellor, D. J. 1983. Nutritional and placental determinants of foetal growth rate in sheep and consequences for the newborn lamb. British Veterinary Journal 139: 307–324.Google Scholar
Mellor, D. J. and Matheson, I. C. 1979. Daily changes in the curved crown-rump length of individual fetuses during the last 60 days of pregnancy and effects of different levels of maternal nutrition. Quarterly Journal of Experimental Physiology 64: 119–131.Google Scholar
Mellor, D. J. and Murray, L. 1982a. Effects of long term undernutrition of the ewe on the growth rates of individual fetuses during late pregnancy. Research in Veterinary Science 32: 177–180.Google Scholar
Mellor, D. J. and Murray, L. 1982b. Effects on the rate of increase in fetal girth of refeeding ewes after short periods of severe undernutrition during late pregnancy. Research in Veterinary Science 32: 377–382.Google Scholar
Milley, J. R. 1993. Ovine fetal protein metabolism during decreased glucose delivery. American Journal of Physiology 265: E525-E531.Google Scholar
National Research Council. 1975. Nutrient requirements of domestic animals. 5. Nutrient requirements of sheep, fifth edition. National Academy of Sciences. National Research Council, Washington, DC.Google Scholar
Nephew, K. P., McClure, K. E., Ott, T. L., Dubois, D. H., Bazer, F. W. and Pope, W. P. 1991. Relationship between variation in conceptus development and differences in estrous cycle duration in ewes. Biology of Reproduction 44: 536–539.Google Scholar
Noblet, J., Dourmad, J. Y., Etienne, M. and Le Dividich, J. 1997. Energy metabolism in pregnant sows and newborn pigs. Journal of Animal Science 75: 2708–2714.Google Scholar
Nordby, D. J., Field, R. A., Riley, M. L. and Kercher, C. J. 1987. Effects of maternal undernutrition during early pregnancy on growth, muscle cellularity, fiber type and carcass composition in lambs. Journal of Animal Science 64: 1419–1427.Google Scholar
Oddy, V. H. and Hoist, P. J. 1991. Maternal-foetal adaptation to mid pregnancy feed restriction in single-bearing ewes. Australian Journal of Agricultural Research 42: 969–978.Google Scholar
Osterby, J., Reynolds, T. S. and Wathes, D. C. 1998. Pregnancy specific regulation of IGFBP-1 expression during early pregnancy in the ewe. Journal of Reproduction and Fertility, Abstract Series 21: 37.Google Scholar
Owens, J. A. 1991. Endocrine and substrate control of fetal growth: placental and maternal influences and insulin-like growth factors. Reproduction, Fertility and Development 3: 501–517.Google Scholar
Owens, J. A., Kind, K. L., Carbone, F., Robinson, J. S. and Owens, P.C. 1994. Circulating insulin-like growth factors -I and -II and substrates in fetal sheep following restriction of placental growth. Journal of Endocrinology 140: 5–13.Google Scholar
Palmer, R. M., Thompson, M. G., Meallet, C., Thorn, A., Aitken, R. P. and Wallace, J. M. 1998. Growth and metabolism of fetal and maternal muscles of adolescent sheep on adequate or high feed intakes: possible role of protein kinase C-a in fetal muscle growth. British Journal of Nutrition 79: 351–357.Google Scholar
Parr, R. A., Davis, I. F., Fairclough, R. J. and Miles, M. A. 1987. Overfeeding during early pregnancy reduces peripheral progesterone concentration and pregnancy rate in sheep. Journal of Reproduction and Fertility 80: 317–320.Google Scholar
Pettigrew, J. E. and Yang, H. 1997. Protein nutrition of gestating sows. Journal of Animal Science 75: 2723–2730.Google Scholar
Reynolds, L. P. and Redmer, D. A. 1995. Utero-placental vascular development and placental function. Journal of Animal Science 73:1839–1851.Google Scholar
Reynolds, T. S., Stevenson, K. R. and Wathes, D. C. 1997a. Pregnancy-specific alterations in the expression of the insulin-like growth factor system during early placental development in the ewe. Endocrinology 138: 886–897.Google Scholar
Reynolds, T. S., Wathes, D. C., Aitken, R. P. and Wallace, J. M. 1997b. Expression of insulin-like growth factor binding protein-5 (IGFBP-5) in the pregnant ovine uterus. Journal of Reproduction and Fertility, Abstract Series 19: 48–49.Google Scholar
Rhind, S. M., McKelvey, W. A. C., McMillen, S., Gunn, R. G. and Elston, D. A. 1989. Effect of restricted food intake, before and/or after mating, on the reproductive performance of Greyface ewes. Animal Production 48: 149–155.Google Scholar
Robinson, J. J. 1990a. Nutrition in the reproduction of farm animals. Nutrition Research Reviews 3: 253–276.Google Scholar
Robinson, J. J. 1990b. Nutrition over the winter period — the breeding female. In New developments in sheep production (ed. Slade, C.F. R. and Lawrence, T. L. J.), occasional publication, British Society of Animal Production, no. 14, pp. 55–69.Google Scholar
Robinson, J. J. 1992. Nutrition and pregnancy in animals. In The contribution of nutrition to human and animal health (ed. Widdowson, E. M. and Mathers, J. C), pp. 203–212. Cambridge University Press.Google Scholar
Robinson, J., Chidzanja, S., Kind, K., Lok, F., Owens, P. and Owens, J. 1995. Placental control of fetal growth. Reproduction, Fertility and Development 7: 333–344.Google Scholar
Robinson, J. J. and McDonald, I., 1989. Ewe nutrition, foetal growth and development. In Reproduction, growth and nutrition in sheep (ed. Dýrmundsson, O. R. and Thorgeirsson, S.), pp. 57–77. Agricultural Research Institute and Agricultural Society, Reykjavik, Iceland.Google Scholar
Robinson, J. J., McDonald, I., Brown, D. S. and Fraser, C. 1985. Studies on reproduction in prolific ewes. 8. The concentrations and rates of accretion of amino acids in the foetuses. Journal of Agricultural Science, Cambridge 105: 21–26.Google Scholar
Robinson, J. J., McDonald, L., Fraser, C. and Gordon, J. G. 1980. Studies on reproduction in prolific ewes. 6. The efficiency of energy utilization for conceptus growth. Journal of Agricultural Science, Cambridge 94: 331–338.Google Scholar
Robinson, J. J. and Symonds, M. E. 1995. Whole body fuel selection: ‘reproduction’. Proceedings of the Nutrition Society 54: 283–299.CrossRefGoogle ScholarPubMed
Rüssel, A.J.F., Doney, J. M. and Gunn, R. G. 1969. Subjective assessment of body fat in live sheep. Journal of Agricultural Science, Cambridge 72: 451–454.Google Scholar
Rüssel, A.J. F., Foot, J. Z., White, I. R. and Davies, G. J. 1981. The effect of weight at mating and of nutrition during mid-pregnancy on the birthweight of lambs from primiparous ewes. Journal of Agricultural Science, Cambridge 97: 723–729.Google Scholar
Seckl, J. R. 1996. Glucocorticoids, feto-placental llß-hydroxysteroid dehydrogenase, fetal growth and the programming of adult disease. In Fetal origins of adult disease — new research directions 1996, pp. 19–20. The Welkome Trust, London.Google Scholar
Sinclair, K. D., Broadbent, P. J., Dolman, D. F., Watt, R. G. and Mullan, J. S. 1995. Establishing twin pregnancies in cattle by embryo transfer. Animal Science 61: 25–33.Google Scholar
Sinclair, K. D., McEvoy, T. G., Carolan, C., Maxfield, E. K., Maltin, C.A., Young, L. E., Wilmut, I., Robinson, J. J. and Broadbent, P. J. 1998. Conceptus growth and development following in vitro culture of ovine embryos in media supplemented with bovine sera. Theriogenology 49: 218.Google Scholar
Sinclair, K. D., Maxfield, E. K., Robinson, J. J., Maltin, C.A., McEvoy, T. G., Dunne, L. D., Young, L. E. and Broadbent, P. J. 1997. Culture of sheep zygotes can alter fetal growth and development. Theriogenology 47: 380.Google Scholar
Spencer, G. S. G. and Robinson, G. M. 1993. Stimulation of placental, fetal and neonatal growth by thyroxine administration to pregnant rats. Journal of Endocrinology 139: 275–279.Google Scholar
Sykes, A. R. and Geenty, K. G. 1986. Calcium and phosphorus balances of lactating ewes at pasture. Journal of Agricultural Science, Cambridge 106: 369–375.Google Scholar
Symonds, M. E. 1995. Pregnancy, parturition and neonatal development: interactions between nutrition and thyroid hormones. Proceedings of the Nutrition Society 54: 329–343.Google Scholar
Symonds, M. E. and Clarke, L. 1996. Nutrition-environment interactions in pregnancy. Nutrition Research Reviews 9: 135–148.CrossRefGoogle ScholarPubMed
Symonds, M. E., Heasman, L., Clarke, L., Firth, K. and Stephenson, T. 1998. Maternal nutrition and disproportionate placental-to-fetal growth. Biochemical Society Transactions 26: 91–96.Google Scholar
Thompson, J. G., Gardner, D. K., Pugh, P. A., McMillen, W. H. and Tervit, H. R. 1995. Lamb birth weight is affected by culture system utilized during in vitro pre-elongation development of ovine embryos. Biology of Reproduction 53: 1385–1391.Google Scholar
Trahair, J. F., DeBarro, T. M., Robinson, J. S. and Owens, J. A. 1997. Restriction of nutrition in utero selectively inhibits gastrointestinal growth in fetal sheep. Journal of Nutrition 127: 637–641.Google Scholar
Walker, S. K., Heard, T. M. and Seamark, R. F. 1992. In vitro culture of sheep embryos without co-culture: successes and perspectives. Theriogenology 37:111–126.Google Scholar
Walker, S. K., Hartwich, K. M. and Seamark, R. F. 1996. The production of unusually large offspring following embryo manipulation: concepts and challenges. Theriogenoiogy 45: 111–120.Google Scholar
Wallace, J. M., Aitken, R. P. and Cheyne, M. A. 1996. Nutrient partitioning and fetal growth in rapidly growing adolescent ewes. Journal of Reproduction and Fertility 107: 183–190.Google Scholar
Wallace, J. M., Bourke, D. A., Aitken, R. P. and Cruickshank, M. A. 1997a. Effect of switching maternal nutrient intake at the end of the first trimester on placental development and fetal growth in adolescent sheep carrying singleton fetuses. Journal of Reproduction and Fertility, Abstract Series 19: 14–15.Google Scholar
Wallace, J. M., Da Silva, P., Aitken, R. P. and Cruickshank, M. A. 1997b. Maternal endocrine status in relation to pregnancy outcome in rapidly growing adolescent sheep. Journal of Endocrinology 155: 359–368.Google Scholar
Wallace, L.R. 1948. The growth of lambs before and after birth in relation to the level of nutrition: parts I, II, and III. Journal of Agricultural Science, Cambridge 38: 93–153, 243-302, 367-401.Google Scholar
Webb, R. and Armstrong, D. G. 1998. Control of ovarian function; effect of local interactions and environmental influences on follicular turnover in cattle: a review. Livestock Production Science 53: 95–112.Google Scholar
West, H. J. 1996. Maternal undernutrition during late pregnancy in sheep. Its relationship to maternal condition, gestation length, hepatic physiology and glucose metabolism. British Journal of Nutrition 75: 593–605.CrossRefGoogle ScholarPubMed
Widdowson, E.M. 1968. Nutrition of the foetus and the newly born. Proceedings of the Nutrition Society 28: 17–24.Google Scholar
Widdowson, E. M. 1976. Environmental control of growth: the maternal environment. In Meat animals, growth and productivity (ed. Lister, D., Rhodes, D. N., Fowler, V. R. and Fuller, M. F.), pp. 273–284. Plenum Press, London.Google Scholar
Williams, R. B. 1977. Trace elements and congenital abnormalities. Proceedings of the Nutrition Society 36: 25–32.Google Scholar
Wise, T., Roberts, A. J. and Christenson, R. K. 1997. Relationships of light and heavy fetuses to uterine position, placental weight, gestational age and fetal cholesterol concentrations. Journal of Animal Science 75: 2197–2207.Google Scholar
Woliny, C., Wassmuth, R., Meinecke-Tillman, S. and Dzapo, V. 1986. Endocrine and enzyme activity and maternal effects in relation to lamb survival. In Factors affecting the survival of newborn lambs (ed. G. Alexander, , Barker, J. D. and Slee, J.), pp. 63–77. Commission of the European Communities, Luxembourg.Google Scholar
Zagrodzki, P., Nicol, F., McCoy, M. A., Smyth, J. A., Kennedy, D. G., Beckett, G. J. and Arthur, J. R. 1998. Iodine deficiency in cattle: compensatory changes in thyroidal selenoenzymes. Research in Veterinary Science 64: 209–211.Google Scholar