Neonatal changes in plasma cortisol, free and total iodothyronine levels in control and hypotrophic lambs

Wrutniak, Chantal; Cabello, Gérard

doi:10.1051/rnd:19870707

Cited by 3 publications

(3 citation statements)

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“…Davicco et al (1982) recorded lamb serum T 4 and T 3 concentrations of 185 and 5.54 nmol/l, respectively, at 6 h post partum, while Kececi (2003) reported thyroid hormone levels at 2 h post partum of 137.45 nmol/l, 3.36 nmol/l, 27.15 pmol/l and 8.47 pmol/l for total T 4, total T 3, free T 4 and free T 3 , respectively. A positive relationship has been reported between BW and serum T 3 and T 4 concentrations in newborn lambs (Wrutniak and Cabello, 1987) and this most likely contributed to the higher thyroid hormone levels in the current study compared with those reported by Kececi (2003) where lamb BW was only 2.77 kg compared with 4.7 and 5.2 kg for C and I-3 lambs, respectively, in the current experiment. Also, contributing to the higher levels of thyroid hormones reported by Davicco et al (1982) would be later sampling time at 6 h post partum, as it has been reported that plasma thyroid hormone levels increase significantly during the first 8 h post partum following which, they decrease rapidly (Cabello and Wrutniak, 1986).…”

Section: Discussionsupporting

confidence: 61%

“…There is a strong relationship between total and free hormonal fractions, indicating that the amount of total T 3 is a major determinant of free T 3 concentration (Cabello and Wrutniak, 1986) while the neonatal rise in free T 4 levels is more important than total T 4 levels as free T 4 is the direct substrate for T 3 production (Wrutniak and Cabello, 1987;Cabello and Wrutniak, 1989). The lower total and free T 3 levels suggest a decline in the peripheral T 4 to T 3 conversion in the I-3 lambs.…”

Section: Discussionmentioning

confidence: 99%

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The effects of cobalt and iodine supplementation of the pregnant ewe diet on immunoglobulin G, vitamin E, T3 and T4 levels in the progeny

Boland

Hayes

Sweeney

et al. 2008

Animal

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Sixty twin-bearing ewes were allocated to one of four dietary treatments investigating the effects of supplementary iodine or cobalt during late pregnancy on lamb serum immunoglobulin G (IgG), triiodothyronine (T 3 ), thyroxine (T 4 ) and vitamin E concentrations, and lamb IgG absorption efficiency. Ewes were offered grass silage ad libitum supplemented with 800 g per ewe per day of a 190 g/kg crude protein (CP) concentrate from day 126 of gestation until parturition plus one of the following supplements (n 5 15 per treatment); no supplement (C); 26.6 mg iodine per day for final 3 weeks pre partum (I-3); 26.6 mg iodine/day for final week pre partum (I-1); 20 mg cobalt/day for final 3 weeks pre partum (Co-3). Lambs were blood sampled at 24 and 72 h post partum for serum IgG and vitamin E concentrations. Ten lambs from C and I-3 were blood sampled at 1 h post partum for serum IgG, vitamin E, T 3 and T 4 concentrations. There were no differences in serum IgG, vitamin E or T 4 values (P . 0.05) at 1 h post partum between lambs born to the C and I-3 ewes. T 3 levels were lower in I-3 compared with C progeny (P , 0.05). Supplemental iodine reduced colostral IgG absorption efficiency (P , 0.001) and lamb serum IgG concentrations at 24 and 72 h post partum (P , 0.001). Serum vitamin E concentration in I-3 and I-1 lambs was lower than in Co-3 lambs at 24 h post partum, while at 72 h post partum I-3, I-1 and Co-3 lambs had significantly lower concentrations than C lambs (P , 0.001). Supplementing the ewe's diet with 26.6 mg/day of iodine for the final week of pregnancy reduced lamb serum IgG concentration at 24 and 72 h post partum. The lower total and free T 3 values in the progeny of I-3-treated ewes suggest interference in the synthesis and metabolism of thyroid hormones when ewes receive excessive dietary iodine for 3 weeks immediately pre partum. Based on these findings, the indications are that the toxicity level for iodine in the diet of the pregnant ewe should be lowered to 20 mg per ewe per day, equivalent to 40% of its current level. The finding that high-level cobalt supplementation during the final 3 weeks of pregnancy will have a negative effect on serum vitamin E concentration at 72 h post partum is a new and significant finding and previously has not been reported in the literature.

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Section: Discussionsupporting

confidence: 61%

Section: Discussionmentioning

confidence: 99%

The effects of cobalt and iodine supplementation of the pregnant ewe diet on immunoglobulin G, vitamin E, T3 and T4 levels in the progeny

Boland

Hayes

Sweeney

et al. 2008

Animal

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“…Similarly, intra-uterine growth retarted lambs displayed T4 and T3 deficiencies during at least the first month of life (Wrutniak & Cabello, 1987b;). The administration of T3, three times a week, improved the growth rate of these animals by 25% during the first month of life (Cabello & Wrutniak, unpublished results).…”

Section: Thyroid Hormone Influences the Fetal Growthmentioning

confidence: 99%

Thyroid hormone and growth : relationships with growth hormone effects and regulation

Cabello¹,

Wrutniak²

1989

Reprod. Nutr. Dévelop.

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― For some years, research in the field of growth endocrinology has been mainly focused on growth hormone (GH). However, it appears that GH does not always control growth rate. For instance, it does not clearly influence intra-uterine growth : moreover, although the results of GRF or GH administration appear convincing in rats, pigs or heifers, this is not the case in chickens and lambs. In addition, GH does not always clearly stimulate somatomedin production, particularly diring food restriction and fetal life, and in hypothyroid animals or sex-linked dwarf chickens. In such situations, this phenomenon is associated with a reduced T3 production, suggesting a significant influence of thyroid function on GH action, and more generally, on body growth. In fact, numerous data demonstrate that thyroid hormone is strongly involved in the regulation of body growth. In species with low maturity at birth, such as the rat. T4 and T3 affect postnatal growth eleven days earlier than the appearance of GH influence. In contrast to GH, thyroid hormone significantly influences fetal growth in sheep. Moreover, the body growth rate is clearly stimulated by T3 in dwarf animals. In addition to its complex metabolic effects involved in the general mechanisms of body growth, thyroid hormone stimulates the production of growth factors, particularly EGF and NGF. Moreover, it affects GH and somatomedin production and also their tissue activity. All these results strongly suggest that it would be difficult to study GH regulation and physiological effects without taking thyroid function into account. body growth ― thyroid hormone ― GH ― GRF ― IGF Résumé ― Hormones thyroïdiennes et croissance. Interactions avec l'axe somatotrope. Depuis plusieurs années, les recherches concernant l'endocrinologie de la croissance sont particulièrement orientées sur l'hormone de croissance (GH). Il semble cependant que le GH ne contrôle pas la croissance dans toutes les situations. Ainsi, elle ne semble pas influencer la croissance intra-utérine; de plus, si les résultats de l'administration de GRF ou de GH sont convaincants chez le rat, le porc ou le bovin, ils s'avèrent plus décevants chez le poulet ou le mouton. D'autre part, la GH n'induit pas toujours une stimulation de la production de somatomédines, notamment pendant la vie intra-utérine, au cours de la restriction alimentaire, ainsi que chez les animaux hypothyroitiiens et chez les poulets nains (nanisme lié au sexe). Dans toutes ces situations particulières, la déficience de stimulation des somatomédines par la GH est associée à une production réduite de T3, ce qui suggère une influence significative de la fonction thyroïdienne sur les effets de la GH, et plus généralement sur la croissance. En fait, de nombreux résultats démontrent que les hormones thryoïdiennes sont impliquées dans la régulation de la croissance corporelle. Chez les espèces à faible maturité à la naissance telles que le rat, la T4 et la T3 influencent la croissance postnatale bien avant qu...

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Plasma leptin concentration in pre- and post-weaning lambs

2003

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Leptin has an important rôle in the control of appetite and energy expenditure. Several studies have reported the effects of leptin in ruminants. However, little is known about changes in circulating leptin concentrations in neonates of ruminant species, or the effects of weaning on plasma leptin concentrations. The main objectives of this experiment were: to examine plasma leptin concentrations in lambs, in the period from just after birth through to weaning; to examine the effect of weaning on plasma leptin concentrations, and to compare leptin concentrations measured using a ‘multi-species’ leptin radio-immunoassay (RIA) kit and a specific ovine RIA in lambs during the 6-month period after weaning. In a previous paper, we reported leptin concentrations using a commercial RIA during the post-weaning period. However, we were not able to measure plasma leptin concentrations from just after birth to weaning as they were apparently below the level of sensitivity of the assay. In the present study, five crossbred lambs were removed from their dams within 2 days after birth, and bottle-fed on milk replacer at a level sufficient to meet a 1•2 times maintenance metabolizable energy intake. Lambs were weaned 45 days after birth, and housed individually in pens. The lambs were offered timothy hay, rolled barley and soya-bean meal to meet a 200 g daily gain during the post-weaning period. During the pre-weaning period, blood samples were collected within 5 h of birth and thereafter at 09:00 h; every day from 2 to 6 days of age; at 2-day intervals from 6 to 14 days of age; and at 3-day intervals from 14 to 45 days of age. During the post-weaning period, blood samples were collected before and 3 and 6 h after the morning meal at the ages of 0•5, 1, 2, 3, 4, 5 and 6 months. Plasma leptin concentrations slightly increased (P < 0•05) just after birth and then remained constant until 45 days old (P > 0•05). Additionally, plasma leptin concentration was not significantly changed following weaning. During the post-weaning period, plasma leptin concentrations were compared using two RIA systems. The correlation between plasma leptin concentrations measured by the ‘multi-species’ leptin RIA kit and specific ovine RIA was poor (r = 0•41). These findings are consistent with other reports and suggest that the ‘multi-species’ leptin RIA kit is not suitable for estimating leptin plasma concentrations in ruminants.

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Neonatal changes in plasma cortisol, free and total iodothyronine levels in control and hypotrophic lambs

Cited by 3 publications

References 12 publications

The effects of cobalt and iodine supplementation of the pregnant ewe diet on immunoglobulin G, vitamin E, T3 and T4 levels in the progeny

The effects of cobalt and iodine supplementation of the pregnant ewe diet on immunoglobulin G, vitamin E, T3 and T4 levels in the progeny

Thyroid hormone and growth : relationships with growth hormone effects and regulation

Plasma leptin concentration in pre- and post-weaning lambs

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