Institute of Animal Science Mariensee

Neustadt an der Weinstraße, Germany

Institute of Animal Science Mariensee

Neustadt an der Weinstraße, Germany
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Hu Y.,Nanjing Agricultural University | Hu Y.,Institute of Poultry Science of Jiangsu Province | Zhang R.,Nanjing Agricultural University | Zhang Y.,Nanjing Agricultural University | And 3 more authors.
Journal of Animal Science and Biotechnology | Year: 2012

Background: A leptin-like immunoreactive substance has been found in chicken eggs and has been implicated in serving as a maternal signal to program offspring growth and metabolism. In the present study, we investigated the effects of in ovo leptin administration on hatch weight, serum and hepatic concentrations of metabolites and hormones, as well as on the expression of genes involved in hepatic lipid metabolism and the predicted microRNAs (miRNAs) targeting the affected genes. To this end we injected fertile eggs with either 0.5 μg of recombinant murine leptin or vehicle (PBS) before incubation.Results: Prenatally leptin-exposed chicks showed lower hatch weight, but higher liver weight relative to the body weight, compared to the control group. In ovo leptin treatment increased the hepatic content and serum concentration of leptin in newly hatched chickens. The hepatic contents of triglycerides (TG) and total cholesterol (Tch) were decreased, whereas the serum levels of TG, Tch and apolipoprotein B (ApoB) were increased. The hepatic mRNA expression of sterol regulator element binding protein 1 (SREBP-1c), SREBP-2, hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and cholesterol 7α-hydroxylase 1 (CYP7A1) was significantly up-regulated, as was the protein content of both SREBP-1c and SREBP-2 in hepatic nuclear extracts of leptin-treated chickens. Moreover, out of 12 miRNAs targeting SREBP-1c and/or HMGCR, five were significantly up-regulated in liver of leptin-treated chicks, including gga-miR-200b and gga-miR-429, which target both SREBP-1c and HMGCR.Conclusions: These results suggest that leptin in ovo decreases hatch weight, and modifies hepatic leptin secretion and lipid metabolism in newly hatched broiler chickens, possibly via microRNA-mediated gene regulation. © 2012 Hu et al; licensee BioMed Central Ltd.

Li R.,Nanjing Agricultural University | Li R.,Shanghai Academy of Agricultural science | Hu Y.,Nanjing Agricultural University | Hu Y.,Institute of Poultry Science of Jiangsu Province | And 4 more authors.
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2011

Hepatic iodothyronine deiodinases (Ds) are involved in the conversion of thyroid hormones (THs) which interacts with growth hormone (GH) to regulate posthatch growth in the chicken. Previous studies suggest that leptin-like immunoreactive substance deposited in the egg may serve as a maternal signal to program posthatch growth. To test the hypothesis that maternal leptin may affect early posthatch growth through modifying hepatic activation of THs, we injected 5.0 μg of recombinant murine leptin into the albumen of breeder eggs before incubation. Furthermore, chicken embryo hepatocytes (CEHs) were treated with leptin in vitro to reveal the direct effect of leptin on expression and activity of Ds. In ovo leptin administration markedly accelerated early posthatch growth, elevated serum levels of total and free triiodothyronine (tT3 and fT3), while that of total thyroxin (tT4) remained unchanged. Hepatic mRNA expression and activity of D1 which converts T4 to T3 or rT3 to T2, were significantly increased in leptin-treated chickens, while those of D3 which converts T3 to T2 or T4 to rT3, were significantly decreased. Moreover, hepatic expression of GHR and IGF-I mRNA was all up-regulated in leptin-treated chickens. Males demonstrated more pronounced responses. A direct effect of leptin on Ds was shown in CEHs cultured in vitro. Expression and activity of D1 were increased, whereas those of D3 were decreased, in leptin-treated cells. These data suggest that in ovo leptin administration improves early posthatch growth, in a gender-specific fashion, probably through improving hepatic activation of THs and up-regulating hepatic expression of GHR and IGF-I. © 2011 Elsevier Inc.

Wei X.J.,Nanjing Agricultural University | Ni Y.D.,Nanjing Agricultural University | Lu L.Z.,Zhejiang Academy of Agricultural Sciences | Grossmann R.,Institute of Animal Science Mariensee | Zhao R.Q.,Nanjing Agricultural University
Animal | Year: 2011

In order to investigate the long-term effects of equol (Eq) on growth and meat quality in broilers, 0 g (control, Con), 20 g (low dose, L) and 100 g (high dose, H) Eq, respectively, were injected into fertile eggs (146 eggs per group) on 7 days of embryos. After hatch, chickens were fed under the same conditions and slaughtered at 49 days of age for sample collection and analysis. The results showed that body weight and composition were marginally affected by Eq administration (P > 0.05). Compared with their male counterparts, the meat quality of female broilers was affected greatly after Eq administration. The redness (a*) of meat color in the L and H groups of female broilers was significantly decreased by 24.10% and 21.50% (P < 0.01), respectively; cooking loss decreased by 12.11% and 16.82%, respectively, in the L and H groups (P < 0.01); 24 h and 48 h drip loss was significantly decreased by 60.27% and 45.72% (P < 0.05), respectively, in the H group. However, for male broilers, only cooking loss was significantly decreased by high dosage of Eq treatment (P < 0.05). The antioxidative status was analyzed for discovering further the mechanism behind the improvement of the water-holding capacity caused by Eq in female broilers. The activity of glutathione peroxidase (GSHPx) in plasma was greatly increased by 15.94% in the L group (P < 0.01), whereas the total superoxide dismutase activity (T-SOD) and the content of malondialdehyde in plasma were not changed (P > 0.05). The T-SOD activity in the breast muscle of the L and H groups were significantly improved by 23.14% and 18.82% (P < 0.05), respectively. GSHPx in the breast muscle of the H group showed a tendency to increase (P = 0.06 < 0.1). These results indicate that Eq injection in ovo does not affect the growth of broilers, but significantly improves the water-holding capacity of the muscle, especially in female broilers, which is related to the improvement of antioxidative status. © The Animal Consortium 2010.

Ni Y.D.,Nanjing Agricultural University | Wei X.J.,Nanjing Agricultural University | Zhang C.X.,Nanjing Agricultural University | Zhong Y.,Nanjing Agricultural University | And 3 more authors.
Animal | Year: 2012

This study investigated the effects of in ovo administration of equol (Eq) on post-hatch growth and hepatic lipid metabolism in broiler chickens. Fertilized eggs (146 eggs/group) were injected with 0 μg (control, Con), 20 μg (low dose, L) and 100 μg (high dose, H) Eq in the albumen on the 7th day of incubation. Except a trend increase in the weight of total fat (P = 0.09), Eq had no effect on growth or liver weight in broilers at 49 days of age. Males presented higher liver and BWs and lower total fat and relative liver weights than females (P < 0.01). However, there were no significant effects of Eq or Eq-gender interactions on growth performance or tissues weight (P > 0.05). With respect to lipid parameters in the serum, the results showed that female broilers presented higher triacyglycerol (TG) and low-density lipoprotein cholesterol concentrations than males, whereas there was no gender difference in serum total cholesterol (TC) or high-density lipoprotein cholesterol (HDLC) concentration (P > 0.05). Eq administration significantly decreased serum TG and TC but increased HDLC concentrations in serum of broilers at 49 days of age (P < 0.05), whereas there were no interactions between gender and Eq (P > 0.05). To elucidate the mechanism behind the significant changes of serum TG and TC levels, the expression of genes involved in lipid metabolism in the liver was investigated in female chickens using reverse transcription-PCR. Carnitine palmitoyl transferase I (CPTI) messenger RNA (mRNA) was significantly upregulated by 20 and 100 μg Eq (P < 0.05). High-dose Eq significantly decreased fatty acid synthase (FAS) and enhanced cholesterol-7alpha-hydroxylase (CYP7A1) mRNA levels in the liver (P < 0.05). Eq had no significant effects on acetyl-CoA carboxylase, sterol regulatory element binding protein-1c, malic enzyme, low-density lipoprotein receptor or 3-hydroxy-3-methylglutaryl coenzyme A reductase mRNA in the liver (P > 0.05). These results in female broilers suggest that Eq decreased blood TG by upregulating CPTI and downregulating FAS mRNA expression in the liver, and that high serum cholesterol levels stimulated CYP7A1 gene transcription in the liver. © The Animal Consortium 2011.

Li L.-A.,Nanjing Agricultural University | Li L.-A.,Tianjin Agricultural University | Wu Z.-W.,Nanjing Agricultural University | Yang X.-J.,Nanjing Agricultural University | And 3 more authors.
In Vitro Cellular and Developmental Biology - Animal | Year: 2011

The present in vitro experiment was designed to test whether 48 h of pretreatment with glucocorticoids, cortisol, or dexamethasone (DEX), would affect basal and corticotrophin (ACTH) stimulated (24 h) cortisol secretion from primary cultures of pig adrenocortical cells. Cells were divided into six groups: control pretreatment with or without ACTH challenge, cortisol pretreatment with or without ACTH challenge, and DEX pretreatment with or without ACTH. The culture medium and cells were collected at the end of treatment. Cortisol concentration in medium was measured by radioimmunoassay, and protein content of glucocorticoid receptor (GR) and key regulatory factors for steroidogenesis, including melanocortin type 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage cytochrome P450 (P450scc), were detected by Western blot analysis. The results showed that glucocorticoid pretreatment did not affect cortisol secretion under basal condition without ACTH challenge, but significantly enhanced ACTH-stimulated cortisol secretion. Furthermore, the protein content of GR, MC2R, StAR, and P450scc was all increased in groups pretreated with glucocorticoids. These results indicate that adrenocortical cells pretreated with glucocorticoids display higher steroidogenic capacity under ACTH challenge, through the upregulation of GR and other steroidogenic regulatory factors. © 2011 The Society for In Vitro Biology.

Ni Y.D.,Nanjing Agricultural University | Wu J.,Nanjing Agricultural University | Tong H.Y.,Nanjing Agricultural University | Huang Y.B.,Nanjing Agricultural University | And 3 more authors.
Animal Feed Science and Technology | Year: 2012

Daidzein, a soy phytoestrogen, is a powerful antioxidant and has multiple biological activities. In this study, the improvement of egg laying rate by feeding daidzein was confirmed again in broiler breeder hens during post-peak egg laying stages, and the mechanism underlying this process was elucidated by the changes of relevant genes expression and the antioxidant status in liver. Three hundred 460-day-old broiler breeders were randomly assigned to 1 of 3 groups (100 birds/10 replicates/group) and were fed a basal diet (control, Con) or the basal diet supplemented with either 5 (low dosage, L) or 10. mg (high dosage, H) of daidzein per kg of diet. After one week adaptation to dietary daidzein, the experiment lasted for 15 days. Both low and high dosage of daidzein supplementation significantly increased the egg-laying rate (P<0.05), but did not change (P>0.05) body weight, oviduct weight, small follicles weight or the number of preovulatory follicles. Serum estrogen showed dose-dependent decrease by daidzein treatment and reached the statistical significance in H group (P<0.05). Serum triiodothyronine and thyroxine concentrations were not altered by daidzein (P>0.05). Daidzein reduced serum malondialdehyde content (P<0.05). In liver, total antioxidant capacity was greatly increased by daidzein (P<0.05), and the activity of glutathione-peroxidase was increased by high level of daidzein treatment (P<0.05), while the activity of superoxide dismutase and the content of malondialdehyde in liver were not changed by daidzein (P>0.05). Real-time PCR analysis showed that, in parallel with the increase of egg laying rate, down-regulation of vitellogenin-II and up-regulation of estrogen receptor β mRNA expression in liver were observed in daidzein treated hens (P<0.05), while estrogen receptor α gene transcription was not affected (P>0.05). The results indicate that dietary daidzein supplementation improves egg-laying rate by increasing the antioxidant capacity and changing the relevant genes transcription in liver of broilers. © 2012 Elsevier B.V.

Ni Y.-D.,Nanjing Agricultural University | Hong W.-J.,Nanjing Agricultural University | Zhou Y.-C.,Nanjing Agricultural University | Grossmann R.,Institute of Animal Science Mariensee | Zhao R.-Q.,Nanjing Agricultural University
Steroids | Year: 2010

Two in vitro systems were employed to delineate the estrogenic activity of daidzein (Da), alone or in combination with high or low concentrations of estrogen in two cell types possessing different estrogen-receptor (ER) isoforms, ERα and/or ERβ: (1) vitellogenin II (VTG), the egg yolk precursor protein and the endpoint biomarker for estrogenicity, in chicken primary hepatocytes, and (2) CHO-K1 cells transiently co-transfected with ERα or ERβ and estrogen-response elements (ERE) linked to a luciferase reporter gene. Da (100 μM) alone induced VTG mRNA expression in chicken hepatocytes, albeit with much less potency compared to estradiol (E2). Da exhibited different effects in the presence of 1 μM and 10 μM E2. At a concentration of 100 μM, Da enhanced 1 μM E2-induced VTG transcription by 2.4-fold, but significantly inhibited 10 μM E2-induced VTG mRNA expression in a dose-dependent fashion from 1 to 100 μM. Tamoxifen completely blocked the estrogenic effect of daidzein, alone or in combination with 1 μM of E2, but did not influence its anti-estrogenic effect on 10 μM E2-induced VTG mRNA expression. Furthermore, neither E2 nor daidzein, alone or in combination, affected ERα mRNA expression, yet all the treatments significantly up-regulated ERβ mRNA expression in chicken hepatocytes. E2 effectively triggered estrogen-response elements (ERE)-driven reporter gene transactivation in CHO-K1 cells expressing ERα or ERβ and showed much greater potency with ERα than with ERβ. In contrast, daidzein was 1000 times more powerful in stimulating ERβ- over ERα-mediated transactivation. Daidzein, in concentrations ranging from 5 nM to 50 μM, did not affect ERβ-mediated transactivation induced by 1 nM E2, but it significantly inhibited ERβ-mediated transactivation induced by 10 nM E2 at 500 nM. Despite the tremendous difference in sensitivity between the two in vitro systems, daidzein exhibited greater potency as an estrogen-antagonist for ERβ-mediated activity. © 2009 Elsevier Inc. All rights reserved.

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