Reproductive hormones, hepatic deiodinase messenger ribonucleic acid, and vasoactive intestinal polypeptide-immunoreactive cells in hypothalamus in the heat stress-induced or chemically induced hypothyroid laying hen

Elnagar, Samar A.; Scheideler, S. E.; Beck, Mary M.

doi:10.3382/ps.2010-00728

Cited by 50 publications

(35 citation statements)

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“…Segundo Miller & Sunde (1975) (Rozenboim et al, 2007, Elnagar et al, 2010) e a progesterona (Novero et al, 1991, Elnagar et al, 2010. Esses hormônios são exigidos para uma atividade reprodutiva normal e, consequentemente, a produção de ovos (Oguntunji & Alabi, 2010).…”

Section: Respostas Fisiológicas E Comportamentais De Galinhas Poedeirunclassified

Ajuste dos níveis de energia e proteína e suas relações para galinhas poedeiras em diferentes condições térmicas

Santana

Saraiva

Costa

et al. 2017

Pubvet

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RESUMO.A adequação das dietas de galinhas poedeiras pode-se tornar uma estratégia essencial para a manutenção dos níveis produtivos das atuais linhagens do mercado. Tendo em vista que os custos com alimentação são os que mais oneram a atividade da avicultura de postura, ajustar principalmente os níveis de energia e proteína das dietas de galinhas poedeiras garante a integridade da qualidade dos ovos, melhoram a qualidade do ambiente e reduzem os custos inerentes à alimentação. Aves adultas mantêm seu conforto térmico com temperaturas entre 18 e 28º C e, tanto oscilações superiores (estresse por calor) ou oscilações inferiores (estresse por frio) são responsáveis por alterações no consumo de alimentos pelos animais, na tentativa de manter a temperatura corporal constante. Em situações de frio as aves aumentam o consumo de ração, na tentativa de produzir calor metabólico e manter a homeotermia. Já no calor, as aves reduzem o consumo de ração e aumentam o consumo de água, reduzindo a produção de calor endógeno e resfriando o corpo pelo gradiente entre a temperatura da água e do núcleo corporal das aves. Mesmo conhecido este mecanismo de ajuste no consumo de alimentos, observa-se que existem poucos relatos científicos acerca da razão energia:proteína em dietas de galinhas poedeiras, sendo assim, o objetivo central desta revisão.Palavras chave: Estresse por calor, gorduras, produção de ovos Adjusting energy and protein levels and their relationships for laying hens in different thermal conditions ABSTRACT. The adequacy of laying hens diets can become an essential strategy for the maintenance of the productive levels of the current lineages of the market. Considering that feed costs are the ones that most affect poultry activity, adjusting the energy and protein levels of laying hens diets ensure egg quality integrity, improves the quality of the environment and reduces costs inherent of food. Adult poultry maintain their thermal comfort with temperatures between 18 and 28º C and, either higher oscillations (heat stress) or lower oscillations (cold stress), are responsible for changes in food consumption by the animals, in an attempt to maintain a constant body temperature. In cold situations birds increase feed intake, in an attempt to produce metabolic heat and maintain homeothermia. In the heat, birds reduce feed intake and increase water consumption, reducing endogenous heat production and cooling the body through the gradient between water temperature and bird's body core. Although this mechanism of adjustment in food consumption is well Silva et al. PUBVETv.12, n.1, a20, p.1-12, Jan., 2018 known, it is observed that there are few scientific reports about the energy: protein ratio in laying hens diets, and thus, the main objective of this review.Keywords: Heat stress, fat, egg production Ajuste de los niveles de energía y proteína y sus relaciones para gallinas ponedoras en diferentes condiciones térmicas RESUMEN: La adecuación de las dietas de gallinas ponedoras puede convertirse en una estrategia esencial para ...

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Section: Respostas Fisiológicas E Comportamentais De Galinhas Poedeirunclassified

Ajuste dos níveis de energia e proteína e suas relações para galinhas poedeiras em diferentes condições térmicas

Santana

Saraiva

Costa

et al. 2017

Pubvet

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“…Under high temperature, the bird's body resists to HS by inducing the release of hypothalamic-pituitary hormones, i.e., they regulate their physiological activities, such as metabolism, immunity, and reproduction, etc. via synthesis and release of hormones related to the adrenal axis, thyroid axis, and gonadal axis (Akazome et al, 2002;Elnagar et al, 2010;Sohail et al, 2010;Yin et al, 2011). HS induces the expression of numerous genes, such as heat shock protein 70, growth-and metabolism-related genes (EGFR, SFRP1, and PDK4), immune-related genes (HSF1, Bcl-2, and Bax-α), reproductive hormone receptor-associated genes (LHR, ESR, PRLR, and FSHR), rhythmic genes (Per2), etc.…”

Section: Introductionmentioning

confidence: 99%

Effect of Heat Stress on the Expression of GABA Receptor mRNA in the HPG Axis of Wenchang Chickens

Xie

et al. 2016

Rev. Bras. Cienc. Avic.

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We investigated the effect of heat stress (HS) on the expression of the GABA receptor in the hypothalamic-pituitary-gonadal (HPG) axis of Wenchang chickens. Real-time quantitative RT-PCR (qRT-PCR) was used to quantify the GABA receptor mRNA levels along the HPG axis of chickens under HS (40±0.5 °C) for 1-6 weeks. Our results showed that the expression of GABA A and GABA B receptor at the mRNAs levels in the tissues of HPG axis exhibited fluctuation and variability. After HS, the mRNA level of GABA A receptor was significantly reduced in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but significantly increased in the pituitary of 1-, 4-, and 5-weekold chickens. The GABA B receptor mRNA level significantly declined in the hypothalamus of 1-week-old and in the pituitary of 3-week-old chickens, but was significantly upregulated in the pituitary and testis of 1-and 2-week-old chickens. At other time points, the expressions of GABA A receptor and GABA B receptor showed no significant differences compared with control group. These results indicated that the levels of GABA A receptor and GABA B receptor mRNAs varied in different tissues of the HPG axis in chickens of different ages, displaying temporal and spatial variations. GABA receptor behaved as a positively-regulated gene by HS, i.e., its mRNA was increased by HS; similarly, it was a negativelyregulated gene by HS, when its expression was reduced by HS.

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“…This is associated with changes in sizes of thyroid gland and its secretion. Heat stress caused hypothyroid effect, decreased plasma progesterone concentration and increased plasma prolactin concentration in Hy-Line laying hens (Elnagar et al, 2010). Estrogen, T 3 and T 3 /T 4 ratio was observed to decrease under heat stressed conditions.…”

Section: Heat Stress and Egg Shell Qualitymentioning

confidence: 93%

Effect of Heat Stress on Physiological Parameters of Layers: A Review

Nidamanuri¹,

Murugesan²,

Mahapatra³

2017

Int. J. Livest. Res.

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Reproductive hormones, hepatic deiodinase messenger ribonucleic acid, and vasoactive intestinal polypeptide-immunoreactive cells in hypothalamus in the heat stress-induced or chemically induced hypothyroid laying hen

Cited by 50 publications

References 50 publications

Ajuste dos níveis de energia e proteína e suas relações para galinhas poedeiras em diferentes condições térmicas

Ajuste dos níveis de energia e proteína e suas relações para galinhas poedeiras em diferentes condições térmicas

Effect of Heat Stress on the Expression of GABA Receptor mRNA in the HPG Axis of Wenchang Chickens

Effect of Heat Stress on Physiological Parameters of Layers: A Review

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