Effect of corticosterone on circulating concentrations of corticosterone, prolactin, thyroid hormones and somatomedin C and on fattening in broilers selected for high or low fat content

Abstract

Daily changes in the concentrations of plasma corticosterone, prolactin, thyroid hormones and somatomedin C were measured in 28-day-old fat and lean lines of broilers produced by selection for high and low concentrations of very low density lipoproteins (VLDL). The effects of daily injections of corticosterone on the concentrations of these hormones and on fattening were compared in the two lines. The selection procedure had no effect on the concentrations of any of the hormones. However, daily rhythms in concentrations of plasma corticosterone, tri-iodothyronine (T3) and prolactin were less often observed in the fat line than in the lean line. No differences were seen between lines in the daily rhythms in plasma thyroxine (T4) and somatomedin C. Daily injections of 2500 micrograms corticosterone/kg body weight, in both lines, depressed mean concentrations of plasma prolactin, T3 and somatomedin C and body weight. This dose of corticosterone also increased abdominal fat pad and liver weights expressed as a percentage of body weight. The liver and fat pad responses to 2500 micrograms corticosterone in both lines were greater when the steroid was injected at the end rather than towards the beginning of the 14-h daily photoperiod. There was no difference between the lines in the fattening response to corticosterone. Lower doses of 100 and 500 micrograms corticosterone per day did not induce fattening or affect concentrations of plasma prolactin. They did, however, depress concentrations of plasma T3. Concentrations of plasma T4 were increased in both lines treated with 2500, but not with 100 or 500 micrograms corticosterone, towards the beginning of the daily photoperiod.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunological and Physiological Differences Between Layer- and Broiler Chickens after Concurrent Intratracheal Administration of Lipopolysaccharide and Human Serum Albumin

“…PBL were isolated from 1 ml heparinized blood, corticosterone were determined in all plasma samples collected on day 0, 7, 14 and 21 post i.t. challenge from obtained at 6 weeks of age using a radioimmunoassay 8 layers and 10 broilers using a discontinuous kit (IDS, Inc. Bolton, UK) according to the manufacturers Histopaque gradient (Sigma) with density 1.191 in 2 ml procedures and described before (Buyse et al, 1987). Eppendorf tubes.…”

Hormones and Metabolism in Poultry

“…Thyroid ablation by the goitrogen methimazole results in markedly lower growth rates (Chaisson et al, 1979;Decuypere et al, 1987) and circulating concentrations of IGF-1 (Decuypere et al, 1987;Rosebrough et al, 2003). Growth rates of chickens are depressed by T3 administration and to a less extent T4 (Decuypere et al, 1987). This would support the concept that normal growth rate in poultry depends on a physiological "set-point".…”

“…• Increased liver weight (Jiang et al, 2008) • Increased hepatic lipogenesis (Lin et al, 2006;Yuan et al, 2008) • Increased abdominal and subcutaneous adipose weight (Bartov, 1982;Buyse et al, 1987;Jiang et al, 2008;Yuan et al, 2008) • Increased circulating concentrations of non-esterified fatty acids (NEFA) (Jiang et al, 2008;Yuan et al, 2008) • Increased circulating concentrations of triglyceride and very low density lipoprotein (VLDL) (Jiang et al, 2008) • Increased adipose lipo-protein lipase (LPL) (Jiang et al, 2008;Yuan et al, 2008).…”

“…The hypothalamic growth hormone -insulin-like growth factor 1 -growth axis in poultry depresses growth rate (Marsh et al, 1984;Bowen et al, 1987). Thyroid ablation by the goitrogen methimazole results in markedly lower growth rates (Chaisson et al, 1979;Decuypere et al, 1987) and circulating concentrations of IGF-1 (Decuypere et al, 1987;Rosebrough et al, 2003). Growth rates of chickens are depressed by T3 administration and to a less extent T4 (Decuypere et al, 1987).…”

Gnawing bones as enrichment for farmed blue foxes (Vulpes lagopus)

“…Buyse et al, 1987;Post et al, 2003;Lin et al, 2006), inflict involution of spleen (Malheiros et al, 2003;Post et al, 2003), and increase the mass of adrenals (Selye, 1950;see Mormede et al, 2007) and liver (Buyse et al, 1987;Malheiros et al, 2003;Lin et al, 2006). The mass of heart, for its part, can Table 2 Percentage of animals with bite marks on the leather side of their skin, severity of bite scars on a subjective scale where 0 denotes 'no bite marks' and 5 'almost the whole skin covered with marks' (mean 6 s.e.…”