Disparate Effects of Stressors on Met-Enkephalin System Parameters and on Plasma Concentrations of Corticosterone in Young Female Chickens.

The effects of stressors were examined on Met-enkephalin-related parameters and plasma concentrations of corticosterone in 14-week-old female chickens. Water deprivation for 24 h was accompanied by a tendency for increased plasma concentration of Met-enkephalin while plasma concentrations of corticosterone were elevated in water-deprived birds. Concentrations of Met-enkephalin were reduced in the anterior pituitary gland and adrenal gland in water-deprived pullets while proenkephalin (PENK) expression was increased in both tissues.

Research Note: Morphine influences circulating and tissue concentrations of met-enkephalin and proenkephalin (PENK) expression and plasma concentrations of corticosterone in chickens.

The effects of the administration of the opioid agonist, morphine, on plasma and tissue concentrations of Met-enkephalin were determined in 14 wk old female chickens. In addition, effects of morphine on proenkephalin (PENK) expression were examined. Plasma concentrations of Met-enkephalin were reduced 10 minutes after morphine administration.

Effects of Restraint Stress on Circulating Corticosterone and Met Enkephalin in Chickens: Induction of Shifts in Insulin Secretion and Carbohydrate Metabolism.

This study examined the effects of acute restraint stress in the presence or absence of naltrexone on the circulating concentrations of insulin, glucose, Met-enkephalin and corticosterone in 14-week-old chickens [design: 2 sex × 2 stress/non-stress × 2 +/- naltrexone]. In chickens (five male and five females per treatment) subjected to restraint for 30 min, there were increases in the plasma concentrations of corticosterone and Met-enkephalin. The plasma concentrations of insulin and glucose were also increased in the chickens during restraint.

Avian opioid peptides: evolutionary considerations, functional roles and a challenge to address critical questions.

The present review considers the putative hormonal opioid peptides in birds. In birds and all other vertebrates, there are four opioid related genes encoding a series of peptides. These genes are, respectively, proenkephalin (PENK), prodynorphin (PDYN), pronociceptin (PNOC) and proopiomelanocortin (POMC).

Response of the hen ovary to eCG treatment: Insight into morphology and expression of genes related to steroidogenesis and vitellogenesis.

The present study aimed to examine the effect of equine chorionic gonadotropin (eCG) treatment on the chicken ovarian folliculogenesis and steroidogenesis. The expression of vitellogenesis-related genes in the liver was also investigated. Laying hens were injected with 75 I.

Discontinuities in understanding follicular development, the ovulatory cycle and the oviposition cycles in the hen: Advances, opportunities, slow downs and complete stops.

There has been considerable progress in understanding follicular development, the ovulatory cycle and the oviposition cycles in the hen. In particular, there have been tremendous advances in understanding follicular development and recruitment of follicles to the hierarchy of large yellow follicles. There is a need to continue to follow the earlier literature while employing present techniques.

A generic avian physiologically-based kinetic (PBK) model and its application in three bird species.

Physiologically-based kinetic (PBK) models are effective tools for designing toxicological studies and conducting extrapolations to inform hazard characterization in risk assessment by filling data gaps and defining safe levels of chemicals. In the present work, a generic avian PBK model for male and female birds was developed using PK-Sim and MoBi from the Open Systems Pharmacology Suite (OSPS). The PBK model includes an ovulation model (egg development) to predict concentrations of chemicals in eggs from dietary exposure.

Quantitative Morphometric, Physiological, and Metabolic Characteristics of Chickens and Mallards for Physiologically Based Kinetic Model Development.

Physiologically based kinetic (PBK) models are a promising tool for xenobiotic environmental risk assessment that could reduce animal testing by predicting exposure. PBK models for birds could further our understanding of species-specific sensitivities to xenobiotics, but would require species-specific parameterization. To this end, we summarize multiple major morphometric and physiological characteristics in chickens, particularly laying hens () and mallards () in a meta-analysis of published data.

Quantitative Comparison of Avian and Mammalian Physiologies for Parameterization of Physiologically Based Kinetic Models.

Physiologically based kinetic (PBK) models facilitate chemical risk assessment by predicting exposure while reducing the need for animal testing. PBK models for mammals have seen significant progress, which has yet to be achieved for avian systems. Here, we quantitatively compare physiological, metabolic and anatomical characteristics between birds and mammals, with the aim of facilitating bird PBK model development.

Antioxidant and antimicrobial activities of phytonutrients as antibiotic substitutes in poultry feed.

Globally, there is increasing demand for safe poultry food products free from antibiotic residues. There is thus a need to develop alternatives to antibiotics with safe nutritional feed derivatives that maximize performance, promote the intestinal immune status, enrich beneficial microbiota, promote health, and reduce the adverse effects of pathogenic infectious microorganisms. With the move away from including antibiotics in poultry diets, botanicals are among the most important alternatives to antibiotics.

Impact of experimentally induced bacterial chondronecrosis with osteomyelitis (BCO) lameness on health, stress, and leg health parameters in broilers.

Stress and lameness negatively affect the health, production, and welfare of broilers. Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of stress and lameness in commercial broilers. External changes in skin temperature related to changes in blood flow can be detected with infrared thermography (IRT), offering a noninvasive tool to assess the health of animals.

Avian Physiology: Are Birds Simply Feathered Mammals?

There are marked differences between the physiology of birds and mammals. These reflect the evolutionary distance between the two classes with the last common ancestor estimated as existing 318 million years ago. There are analogous organ systems in birds and mammals.

Broiler stress responses to light intensity, flooring type, and leg weakness as assessed by heterophil-to-lymphocyte ratios, serum corticosterone, infrared thermography, and latency to lie.

Stress and leg weakness are detrimental to broiler production, health, and welfare. Traditional methods to evaluate stress may be stressful to the bird because they are invasive and require handling and restraint. Two studies examined the effects of light intensity and flooring on the following in broilers: 1) traditional methods for assessing stress using heterophil-to-lymphocyte ratios and serum corticosterone (CORT) concentrations, 2) noninvasive measures of stress from infrared thermography (IRT) eye and beak surface temperatures, and 3) latency-to-lie (LTL) test times of birds tested individually and in groups of 5.

Effect of transportation and shackling on plasma concentrations of corticosterone and heterophil to lymphocyte ratios in market weight male turkeys in a commercial operation.

There is limited information on the effects of stress and/or physiological manipulation on either plasma concentrations of corticosterone (CORT) and/or heterophil: lymphocyte (H : L) ratios in turkeys. The present studies examine the effects of catching/transportation/lairage in a holding shed and shackling on plasma concentrations of CORT and H : L ratios in male market weight turkeys. Plasma concentrations of CORT were increased after transportation and lairage but not further elevated by shackling, irrespective of its duration up to 240 s.

Effects of putative stressors and adrenocorticotropic hormone on plasma concentrations of corticosterone in market-weight male turkeys.

There is limited information on the effects of stress and/or physiological manipulation on plasma concentrations of corticosterone (CORT) in turkeys. Under basal conditions, there was evidence for episodic release of CORT in turkeys. The present studies determine the effects of handling, herding, herding, the administration of Escherichia coli endotoxin, and challenge with turkey adrenocorticotropic hormone (ACTH) on plasma concentrations of CORT in market-weight male turkeys.

Opioid-like peptides and ghrelin mitigation of bariatric results depends on obesity level.

Introduction: Bariatric surgery, as the only effective treatment of obesity, has strong effects on the metabolism, and nervous and endocrine systems. Thus, based on the different opinions about the efficaciousness of morbid obesity treatments, the aim of the present study was to estimate the association of serum ghrelin and Met-enkephalin (native, five amino acids and cryptic, precursor of enkephalin) concentrations with body mass index (BMI) value in bariatric patients within 30 postoperative days.

Material And Methods: The study was performed on 38 female patients divided into two groups: I - BMI lower than 40 kg/m² (n = 18) and II - BMI higher than 40 kg/m² (n = 20).

Thermal Micro-Environment during Poultry Transportation in South Central United States.

This observational study was conducted to characterize the thermal micro- climate that broilers experienced in commercial poultry transporters under various weather conditions and typical management practices in the South Central USA. We continuously monitored temperature and relative humidity in 45 interior locations of 28 fully-loaded commercial trailers over 2 year spans from 2015⁻2016 in South Central USA. In the cold season, double boarding of the exterior area of the transport modules maintained temperatures at least 8 °C warmer than ambient temperatures as low as -16 °C.

Isolation stress impacts Met-enkephalin in the hypothalamo-pituitary-adrenocortical axis in growing Polish Mountain sheep: a possible role of the opioids in modulation of HPA axis.

It was hypothesized that there is cross-talk between the classical constituents of the hypothalamo-pituitary-adrenocortical axis (HPA) and Met-enkephalin in the HPA axis. The study examined effects of isolation stress, sex, and age on concentrations of native Met-enkephalin and pro-enkephalin (PENK) gene expression in tissues of the HPA (hypothalamus, pituitary gland and adrenal cortex) in 3-, 6- and 9-month old female and male lambs. In addition, the effects of isolation stress on in vitro release Met-enkephalin from fragments of the hypothalamus or adrenal cortex were examined.

Perspectives on Endogenous Opioids in Birds.

The present review summarizes the state of knowledge of endogenous opioids in birds. Endogenous opioid peptides acts in a neuromodulatory, hormonal and paracrine manner to mediate analgesic and other physiological functions. These peptides act through specific G-protein coupled receptors.

The utility of infrared thermography for evaluating lameness attributable to bacterial chondronecrosis with osteomyelitis.

Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of lameness in broilers. Infrared thermography (IRT) is a noninvasive technique for measuring infrared radiation from an object and can be used to evaluate clinical health. Two replicated studies compared the effect of light intensity on broilers grown on a wire flooring model that experimentally increased their susceptibility to and incidence of BCO lameness.

Endocrine implications of obesity and bariatric surgery.

Introduction: Obesity is a highly prevalent disease in the world associated with the disorders of endocrine system. Recently, it may be concluded that the only effective treatment of obesity remains bariatric surgery. The aim of the review was to compare the concepts of appetite hormonal regulation, reasons of obesity development and bariatric procedures published over the last decade.