scholarly journals Effects of Sex-Linked Imperfect Albinism (sal-s) in the Chicken on the Relationships of Plasma Concentrations of Progesterone and 17β-Estradiol with Egg Production

1996 ◽  
Vol 75 (1) ◽  
pp. 13-19 ◽  
Author(s):  
H. SU ◽  
F.G. SILVERSIDES ◽  
P. VILLENEUVE
Keyword(s):  
Egg Production ◽  
Plasma Concentrations ◽  
17Β Estradiol

scholarly journals Mechanisms regulating oocyte recruitment and skipped spawning in Northeast Arctic cod (Gadus morhua)

2009 ◽  
Vol 66 (9) ◽  
pp. 1582-1596 ◽  
Author(s):  
Jon Egil Skjæraasen ◽  
James Kennedy ◽  
Anders Thorsen ◽  
Merete Fonn ◽  
Bente Njøs Strand ◽  
...  
Keyword(s):  
Egg Production ◽  
Gadus Morhua ◽  
Energy Reserves ◽  
Lower Plasma ◽  
Arctic Cod ◽  
Food Regimes ◽  
Skipped Spawning ◽  
Physical Measurements ◽  
Stock Recruitment ◽  
17Β Estradiol

To examine mechanisms that affect fecundity, atresia, and skipped spawning in Northeast Arctic cod ( Gadus morhua ), we conducted an experiment where wild-caught cod (>60 cm) kept under restricted food regimes were subjected to monthly biopsies and hormonal and physical measurements. The power of body weight as a fecundity proxy increased until the presumed end of follicle proliferation in early November; thereafter, it remained stable. Atresia occurred in most females, but for maturing females, mainly close to spawning. Eighteen percent of the females had small gonads with predominantly previtellogenic oocytes at sacrifice in January. These females were past-spawners, verified by postovulatory follicles in their gonads. These “skippers” had lower condition than maturing cod from December, smaller livers upon sacrifice, and lower plasma 17β-estradiol values from early November. Until November, oocytes developed similarly for all females, but in November, oocyte development was arrested at the early cortical alveoli stage and atresia occurred in all skippers. In summary, fecundity and skipped spawning seem highly influenced by energy reserves during early vitellogenesis and was limited to females only. Finally, skippers were identifiable long before the predicted onset of spawning, which could have implications for forecasting of egg production and hence stock–recruitment relationships.

scholarly journals Warm Perches: A Novel Approach For Reducing Cold Stress Effect on Production, Plasma Hormones, and Immunity in Laying Hens

2021 ◽  
Author(s):  
Jiaying Hu ◽  
Heng Wei Cheng
Keyword(s):  
Body Weight ◽  
Cold Stress ◽  
Cold Exposure ◽  
Feed Intake ◽  
Plasma Levels ◽  
Egg Production ◽  
Laying Hens ◽  
Plasma Concentrations ◽  
Economic Losses ◽  
Stress Effect

Abstract Background: Cold temperature is a common environmental stressor that has a great impact on the poultry industries, inducing pathophysiological stress in birds with profound economic losses. Current methods used for preventing cold stress, such as reducing ventilation and using gas heaters, are facing challenges due to poor indoor air quality and its deleterious effects on bird and caretaker health. The aim of this study was to examine if the novelly designed warmed perch system, as a thermal device, can reduce cold stress-associated adverse effects on laying hens. Methods: Seventy-two 32-week-old DeKalb hens were randomly assigned to 36 cages arranged to 3 banks. The banks were assigned to 1 of 3 treatments: cages with warmed perches (WP; perches with circulating water at 30 oC), air perches (AP, regular perches only) or no perches (NP) for a 21- day trial. The room temperature was set at 10 oC during the entire experimental period. Rectal temperature and body weight were measured from the same bird of each cage at day 1, 8, 15, and 21 during the cold exposure. Egg production was recorded daily. Feed intake, egg and eggshell quality were determined during the 1st and 3rd week of cold stress. Plasma levels of corticosterone, thyroid hormones (3, 3’, 5-triiodothyronine and thyroxine), interleukin (IL)-6 and IL-10, were determined at day 1 and 21 post initiation of cold exposure. Results: Compared to both AP and NP hens, WP hens were able to maintain their body temperature without increasing feed intake and losing body weight. The eggs laid by WP hens had thicker eggshell during the 3rd week of cold exposure. Warmed perch hens also had a lower thyroxine conversion rate (3, 3’, 5-triiodothyronine/thyroxine) at day 1, while higher plasma concentrations of IL-6 at day 21. Plasma levels of corticosterone, 3, 3’, 5-triiodothyronine, and IL-10 were not different among treatments. Conclusions: Our results indicate that the warmed perch system can be used as a novel thermal device for preventing cold stress-induced negative effects on hen health and welfare through regulating innate immunity and metabolic hormonal homeostasis.

Effects of high levels of vitamin e supplementation in heat stressed laying hens

1995 ◽  
Vol 1995 ◽  
pp. 49-49
Author(s):  
Sandy Bollengier ◽  
G. Uzu ◽  
P.E.V. Williams ◽  
C.C. Whitehead
Keyword(s):  
Heat Stress ◽  
Vitamin E ◽  
Egg Production ◽  
Laying Hens ◽  
Plasma Concentrations ◽  
Short Exposure ◽  
Dietary Vitamin ◽  
Small Scale ◽  
Supplemental Vitamin ◽  
High Level

It was investigated in a small-scale study using a climate-controlled room at IAPGR, Roslin, that the effects of feeding a high level of supplemental vitamin E (500 mg/kg) on egg production and plasma concentrations of egg-associated metabolites in laying hens subjected to a short exposure (7 days) to a moderate heat stress (temperature of 32°C). The study showed, on small group sizes (12 birds / group), that in control birds (fed 30 mg supplemental vitamin E/kg), this degree of heat stress depressed egg production by about 30%. In the birds receiving the high level of vitamin E, egg production was maintained at levels very close to those prior to the heat stress. The objective of this experiment was to confirm in a larger scale the effects of high levels of dietary vitamin E on egg production of hens exposed to a chronic heat stress and during a period of recovery at thermoneutral temperatures.

scholarly journals Short-term administration of progesterone and estradiol independently alter carotid-vasomotor, but not carotid-cardiac, baroreflex function in young women

2013 ◽  
Vol 305 (7) ◽  
pp. H1041-H1049 ◽  
Author(s):  
Vienna E. Brunt ◽  
Jennifer A. Miner ◽  
Paul F. Kaplan ◽  
John R. Halliwill ◽  
Lisa A. Strycker ◽  
...  
Keyword(s):  
Young Women ◽  
Baroreflex Sensitivity ◽  
Mixed Model ◽  
Plasma Concentrations ◽  
Baroreflex Function ◽  
Hormone Effects ◽  
Term Administration ◽  
17Β Estradiol ◽  
The Individual ◽  
Neck Pressure

The individual effects of estrogen and progesterone on baroreflex function remain poorly understood. We sought to determine how estradiol (E2) and progesterone (P4) independently alter the carotid-cardiac and carotid-vasomotor baroreflexes in young women by using a hormone suppression and exogenous add-back design. Thirty-two young women were divided into two groups and studied under three conditions: 1) after 4 days of endogenous hormone suppression with a gonadotropin releasing hormone antagonist (control condition), 2) after continued suppression and 3 to 4 days of supplementation with either 200 mg/day oral progesterone ( N = 16) or 0.1 to 0.2 mg/day transdermal 17β-estradiol ( N = 16), and 3) after continued suppression and 3 to 4 days of supplementation with both hormones. Changes in heart rate (HR), mean arterial pressure (MAP), and femoral vascular conductance (FVC) were measured in response to 5 s of +50 mmHg external neck pressure to unload the carotid baroreceptors. Significant hormone effects on the change in HR, MAP, and FVC from baseline at the onset of neck pressure were determined using mixed model covariate analyses accounting for P4 and E2 plasma concentrations. Neither P4 ( P = 0.95) nor E2 ( P = 0.95) affected the HR response to neck pressure. Higher P4 concentrations were associated with an attenuated fall in FVC ( P = 0.01), whereas higher E2 concentrations were associated with an augmented fall in FVC ( P = 0.02). Higher E2 was also associated with an augmented rise in MAP ( P = 0.01). We conclude that progesterone blunts whereas estradiol enhances carotid-vasomotor baroreflex sensitivity, perhaps explaining why no differences in sympathetic baroreflex sensitivity are commonly reported between low and high combined hormone phases of the menstrual cycle.

17β-Estradiol corrects hemostasis in uremic rats by limiting vascular expression of nitric oxide synthases

2000 ◽  
Vol 279 (4) ◽  
pp. F626-F635 ◽  
Author(s):  
Marina Noris ◽  
Marta Todeschini ◽  
Sergio Zappella ◽  
Samantha Bonazzola ◽  
Carla Zoja ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bleeding Time ◽  
Plasma Concentrations ◽  
Immunoperoxidase Staining ◽  
Conjugated Estrogens ◽  
Prolonged Bleeding ◽  
Primary Hemostasis ◽  
Prolonged Bleeding Time ◽  
17Β Estradiol ◽  
Conjugated Estrogen

Conjugated estrogens shorten the prolonged bleeding time in uremic patients and are similarly effective in a rat model of uremia. We have previously demonstrated that the shortening effect of a conjugated estrogen mixture or 17β-estradiol on bleeding time was abolished by the nitric oxide (NO) precursor l-arginine, suggesting that the effect of these drugs on hemostasis in uremia might be mediated by changes in the NO synthetic pathway. The present study investigated the biochemical mechanism(s) by which conjugated estrogens limit the excessive formation of NO. 17β-estradiol (0.6 mg/kg), given to rats made uremic by reduction of renal mass, significantly reduced bleeding time within 24 h and completely normalized plasma concentrations of the NO metabolites, nitrites and nitrates, and of NO synthase (NOS) catalytic activity, determined by NADPH-diaphorase staining in the thoracic aorta. Endothelial NOS (ecNOS) and inducible NOS (iNOS) immunoperoxidase staining in the endothelium of uremic aortas of untreated rats was significantly more intense than in control rats, while in uremic rats receiving 17β-estradiol staining was comparable to controls. Thus 17β-estradiol corrected the prolonged bleeding time of uremic rats and fully normalized the formation of NO by reducing the expression of ecNOS and iNOS in vascular endothelium. These results provide a possible biochemical explanation of the well-known effect of estrogens on primary hemostasis in uremia, in experimental animals and humans.

scholarly journals Changes in the plasma concentrations of free amino acids in relation to egg formation in the hen

1970 ◽  
Vol 24 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
T. G. Taylor ◽  
J. J. Waring ◽  
R. K. Scougall
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Egg Production ◽  
Nutritive Value ◽  
Plasma Concentrations ◽  
Essential Amino Acids ◽  
Egg Formation ◽  
Amino Acid Requirements

1. The changes occurring in the free amino acids of the plasma of laying hens in relation to egg formation have been investigated in fed and starved hens in three experiments, each with eight birds.2. The mean concentrations of most amino acids and of the totals were higher at night than in the morning.3. In general, egg formation was associated with increases in the concentrations of non- essential and decreases in the concentrations of essential amino acids. Cystine and glutamic acid tended to behave like the essential amino acids.4. After 40 h starvation seven amino acids, particularly serine, histidine and lysine, in- creased in concentration and only three, proline, ornithine and arginine, decreased significantly.5. When eight cocks were injected with oestrogen most of the amino acids increased in con-centration. The essential amino acids (with the exception of phenylalanine), serine, proline, cystine and ornithine showed the greatest increases.6. The results are discussed in relation to the possibility that the voluntary food intake of hens may be influenced by changes in the plasma levels of one or more essential amino acids associated with the synthesis of egg albumen. Arginine appeared to be the only amino acid that might possibly fulfil this role.7. It was concluded that investigations of changes in the free amino acids of hen plasma are unlikely to provide a useful approach to a study of the amino acid requirements or the nutritive value of particular proteins for egg production.

scholarly journals Newcastle Disease Virus Induced Pathologies Severely Affect the Exocrine and Endocrine Functions of the Pancreas in Chickens

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 495
Author(s):  
Zaib Ur Rehman ◽  
Shanhui Ren ◽  
Salman Latif Butt ◽  
Zahid Manzoor ◽  
Javid Iqbal ◽  
...  
Keyword(s):  
Newcastle Disease Virus ◽  
Disease Virus ◽  
Newcastle Disease ◽  
Plasma Levels ◽  
Egg Production ◽  
Vaccine Development ◽  
Histopathological Examination ◽  
Plasma Concentrations ◽  
Economic Losses ◽  
High Morbidity

Newcastle disease virus (NDV) causes a highly contagious and devastating disease in poultry. ND causes heavy economic losses to the global poultry industry by decreasing the growth rate, decrease in egg production high morbidity and mortality. Although significant advances have been made in the vaccine development, outbreaks are reported in vaccinated birds. In this study, we report the damage caused by NDV infection in the pancreatic tissues of vaccinated and specific-pathogen-free chickens. The histopathological examination of the pancreas showed severe damage in the form of partial depletion of zymogen granules, acinar cell vacuolization, necrosis, apoptosis, congestion in the large and small vessels, sloughing of epithelial cells of the pancreatic duct, and mild perivascular edema. Increased plasma levels of corticosterone and somatostatin were observed in NDV-infected chicken at three- and five- days post infection (DPI). A slight decrease in the plasma concentrations of insulin was noticed at 5 DPI. Significant changes were not observed in the plasma levels of glucagon. Furthermore, NDV infection decreased the activity and mRNA expression of amylase, lipase, and trypsin from the pancreas. Taken together, our findings highlight that NDV induces extensive tissue damage in the pancreas, decreases the activity and expression of pancreatic enzymes, and increases plasma corticosterone and somatostatin. These findings provide new insights that a defective pancreas may be one of the reasons for decreased growth performance after NDV infection in chickens.

Blood levels of ionized calcium, inorganic phosphorus, 1,25-dihydroxycholecalciferol and gonadal hormones in hens laying hard-shelled or shell-less eggs

1986 ◽  
Vol 111 (1) ◽  
pp. 151-157 ◽  
Author(s):  
Y. Nys ◽  
T. M. N'Guyen ◽  
J. Williams ◽  
R. J. Etches
Keyword(s):  
Egg Production ◽  
Plasma Concentrations ◽  
Inorganic Phosphorus ◽  
Gonadal Hormones ◽  
Ionized Calcium ◽  
Control Group ◽  
Blood Levels ◽  
Shell Formation ◽  
Ovulatory Cycle ◽  
Egg Formation

ABSTRACT The production of shell-less eggs was induced in hens to measure the effects of the high demands made by shell formation on the blood minerals and hormones whose concentrations change during egg formation. In control hens laying hard-shelled eggs, the concentration of ionized calcium in plasma decreased at the onset of shell formation, but no change was found in hens laying shell-less eggs. Total calcium concentrations in plasma decreased slightly throughout the ovulation cycle in both groups. Concentrations of inorganic phosphorus in the plasma were increased in the control group during the period of shell formation and decreased when calcification was suppressed. Finally, the concentrations of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) in plasma were significantly increased 16 and 20 h following an ovulation compared with 4 h after ovulation, or compared with the concentrations observed in hens laying shell-less eggs. The variations in the plasma concentrations of ionized calcium, inorganic phosphorus and 1,25-(OH)2D3 associated with egg formation were therefore absent in hens laying shell-less eggs demonstrating their direct link with shell calcification. On the other hand, suppression of shell production had no influence on the changes in the plasma concentrations of progesterone, oestradiol and testosterone which are associated with the normal ovulatory cycle. It is concluded that the increases in intestinal and uterine calcium transport and in 1,25-(OH)2D3 production which occur at the onset of egg production in hens are mainly controlled by factors involved in maintaining calcium homeostasis rather than by gonadal hormones. J. Endocr. (1986) 111, 151–157

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