45Calcium dynamics of hens laying thick- or thin-shelled eggs

1994 ◽  
Vol 74 (3) ◽  
pp. 541-546 ◽  
Author(s):  
Martin Clunies ◽  
Steve Leeson
Keyword(s):  
Plasma Proteins ◽  
Phosphorus Content ◽  
Specific Activity ◽  
Shell Formation ◽  
Intubation Time ◽  
Medullary Bone ◽  
Ovulatory Cycle ◽  
Post Intubation ◽  
Thick Shells ◽  
Single Comb

An experiment was carried out to investigate rate of shell secretion in two groups of hens selected for differences in shell deformation. Forty 50-wk-old Single Comb White Leghorn hens from two groups shown to produce eggs differing in shell thickness were fed a 3.5% Ca diet. Hens in their third to fifth ovulatory cycle of a sequence were intubated with 15 μCi of 45Ca 0.5 h post-oviposition. At 6, 12, 15 and 24 h, post-intubation blood was collected from five hens, which were subsequently euthanized, and bone samples were taken.Hens producing thick shells had higher (P < 0.05) plasma proteins, although there was no difference (P > 0.05) in plasma Ca or plasma protein-bound phosphorus content. While plasma 45Ca specific activity decreased (P < 0.05) with post-intubation time, there were no differences (P > 0.05) in plasma 45Ca specific activity between the two groups of hens. There were no differences (P > 0.05) in Ca reserves of bone ends or medullary bone alone or combined for hens secreting either thick- or thin-shelled eggs, nor were there any changes (P > 0.05) in these parameters with post-intubation time. Total 45Ca and 45Ca specific activity of both bone ends and medullary bone decreased as the ovulatory cycle proceeded. Regression analysis showed that the rate of depletion of 45Ca from the bone compartment, as indicated by the slope coefficient, was greatest for hens selected to produce thicker shells (Y = 13.8 − 3.11X1, R2 = 0.351, RSD = ± 4.917 for thick-shelled hens; Y = 6.7 − 0.95X1, R2 = 0.360, RSD = 1.1479 for thin shelled hens, where Y is the percentage 45Ca-intubated bone; and X1 is the time in hours). Key words: Calcium, shell formation, bone

Effect of dietary calcium level on plasma proteins and calcium flux occurring during a 24 h ovulatory cycle

1995 ◽  
Vol 75 (3) ◽  
pp. 439-444 ◽  
Author(s):  
M. Clunies ◽  
S. Leeson
Keyword(s):  
Key Words ◽  
Calcium Level ◽  
Plasma Proteins ◽  
Calcium Flux ◽  
Shell Formation ◽  
White Leghorn ◽  
Medullary Bone ◽  
Ovulatory Cycle ◽  
Key Words Calcium ◽  
Single Comb

An experiment was carried out to determine whether feeding different calcium levels from the onset of production has an effect on medullary bone reserves, plasma proteins and ultimately shell formation. A total of 80 Single Comb White Leghorn hens photostimulated at 17 wk of age were fed a 2.5% Ca diet until the appearance of the first egg. Thereafter diets providing 2.5, 3.0, 3.5, 4.0, or 4.5% Ca were fed to groups of 16 hens. At 6, 12, 18, or 24 h post-ovrposition, blood was collected from four hens per treatment, which were then euthanized and developing shells and bones sampled. As dietary Ca increased, plasma Ca, protein, and protein-bound phosphorus concentrations also increased (P < 0.05). Dietary Ca level had no effect (P > 0.05) on the % Ca or total Ca content of bone ends or medullary bone. As dietary Ca concentration increased, both shell ash and shell Ca increased (P < 0.05). Regardless of dietary Ca, shell secretion was most rapid during 12–18 h of the ovulatory cycle (postoviposition). Key words: Calcium, medullary bone, shell calcification, plasma proteins

Bone composition and Ca45 retention in fowl as influenced by egg formation

1964 ◽  
Vol 206 (1) ◽  
pp. 198-204 ◽  
Author(s):  
S. Hurwitz
Keyword(s):  
Blood Plasma ◽  
Phosphorus Content ◽  
Specific Activity ◽  
High Specific Activity ◽  
Medullary Bone ◽  
Egg Formation ◽  
Calcium Phosphorus ◽  
Calcium And Phosphorus ◽  
Reproductive Cycles ◽  
Stable Calcium

Ca45 was intravenously administered to laying hens close to the time of ovulation. Groups of five birds were killed at intervals ranging from 30 min to 14 days, after dosing, and calcium, phosphorus, and radioassays were made on their blood plasma, on ends and cortical and medullary segments of their tibias and femurs, and on eggs laid previous to killing. Radioactivity in blood plasma and eggs decreased with time. There were no significant changes in amount and calcium and phosphorus content of tibia and femur segments during one and more reproductive cycles. Radioactivity of bone segments increased to 2 hr after dosing and later markedly declined, paralleling eggshell deposition. Specific activity of the medullary segment was higher than that of ends or cortical segment. It is suggested that the decline in radioactivity of bone is caused mainly by exchange with stable calcium during its transfer from gut to eggshell, although resorption of bone may also take place. The high specific activity of medullary bone 2 days after dosing suggests a greater turnover of calcium in this segment than in the other segment studied.

Role of plasma lipids in transport of fatty acids for butterfat formation

1960 ◽  
Vol 198 (1) ◽  
pp. 45-47 ◽  
Author(s):  
P. M. Riis ◽  
Jack R. Luick ◽  
Max Kleiber
Keyword(s):  
Fatty Acids ◽  
Plasma Proteins ◽  
Turnover Rate ◽  
Plasma Lipids ◽  
Specific Activity ◽  
Plasma Lipid ◽  
Half Time

Cow plasma containing P32- and C14-labeled lipids and proteins was infused into a lactating cow. The specific activity of the lipids and volatile acids of the plasma and of the expired CO2 and milk constituents was determined. The turnover rate of phospholipid P and of plasma lipid volatile acids was 0.1 hours–1, this means a half-time of 7 hours. Little radioactivity was found in the expired CO2 and none was found in plasma volatile acids. These findings and the distribution of C14 in milk constituents indicate that plasma proteins do not contribute carbon to butterfat and that the catabolism of plasma lipids and proteins does not lead to a significant formation of nonlipid butterfat precursors. These observations permit a further calculation which indicates that 50% of the butterfat C originates from plasma lipid C.

scholarly journals Protein turnover in skeletal muscle of piglets

1974 ◽  
Vol 31 (1) ◽  
pp. 35-45 ◽  
Author(s):  
H. N. Perry
Keyword(s):  
Protein Turnover ◽  
Plasma Proteins ◽  
Hind Limb ◽  
Acid Metabolism ◽  
Specific Activity ◽  
Whole Body ◽  
Myofibrillar Proteins ◽  
Sarcoplasmic Proteins ◽  
Sarcoplasmic Protein ◽  
Suckling Piglets

1. Rates of protein synthesis and catabolism were measured in longissimus dorsi and hind-limb muscles of suckling piglets.2. Half-lives for synthesis and catabolism for mixed sarcoplasmic proteins were 4.8 and 9.4 d respectively. The corresponding values for mixed myofibrillar proteins were 5.7 and 16.4 d.3. The half-lives for synthesis of sarcoplasmic proteins were significantly different from those of myofibrillar proteins and were not confounded by contamination of the sarcoplasmic protein fraction with plasma proteins of higher specific activity.4. Individual myofibrillar proteins were synthesized and catabolized at rates which were not statistically significantly different. Intramuscular connective tissue also appeared to turnover rapidly, the half-life for synthesis being 8 d and that for catabolism 20 d.5. Values obtained for the specific radioactivities of aspartate + glutamate in mixed plasma proteins support the view that, in so far as the young of animals larger in mature body size than rats or mice are concerned, muscle assumes a more important role relative to liver in regulating whole body amino acid metabolism.

Calcium turnover in different bone segments of laying fowl

1965 ◽  
Vol 208 (1) ◽  
pp. 203-207 ◽  
Author(s):  
S. Hurwitz
Keyword(s):  
Turnover Rate ◽  
Laying Hens ◽  
Accretion Rate ◽  
Specific Activity ◽  
Maximum Level ◽  
Shell Formation ◽  
Exchangeable Ca ◽  
Continuous Feeding ◽  
Egg Shell

The turnover of calcium in various bone segments was studied by a single-dose technique in Nicarbazin-treated hens, and by a long-term feeding of a Ca45-labeled diet in normal laying hens. Nicarbazin treatment prevented ovulation and shell formation with only a slight effect on plasma Ca concentration. In the treated hens, exchangeable Ca comprised 3.3%, 0.5%, and 5.2% of the Ca in femur ends, cortical, and medullary segments, respectively. Accretion rate was highest in the medullary and lowest in the cortical segment. Results of the long-term Ca45 feeding indicate the following sequence for the turnover rate of Ca in bone segments: tibia medullary = femur medullary >> femur ends > tibia ends = sternum > humerus ends > femur cortical > tibia cortical = humerus cortical. During a 12-day period at least 70% of Ca in the medullary segment was replaced. On continuous feeding of Ca45 to laying hens, plasma and egg-shell specific activity reached a maximum level, higher than that of the diet, between 12 and 20 days.

Prediction of the phosphorus content of herbage consumed by grazing cattle

1977 ◽  
Vol 88 (3) ◽  
pp. 533-538 ◽  
Author(s):  
D. A. Little ◽  
R. W. McLean ◽  
W. H. Winter
Keyword(s):  
Intravenous Infusion ◽  
Phosphorus Content ◽  
Specific Activity ◽  
Accurate Prediction ◽  
Degree Of Reduction ◽  
Grazing Cattle ◽  
Specific Activities ◽  
Highly Correlated

SUMMARYThe determination of feed phosphorus content using oesophageally fistulated cattle is reported in this paper, from an experiment in which salivary phosphorus was labelled with 32P.An intravenous infusion of Na232PO4 to cattle produced an immediate increase in the specific activity of salivary phosphorus, which then fell rapidly to an essentially linear asymptote by 3 h after the infusion. The phosphorus content of consumed feed was calculated from the degree of reduction in salivary specific activity by the feed phosphorus, expressed as the ratio of the specific activities of bolus and saliva phosphorus.A dose of 100 /μCi 32P allowed the accurate prediction of phosphorus content ranging from 0·07 to 0·25% in various feeds, at intervals from 3 to 24 h after the infusion; the predicted and actual phosphorus concentrations were highly correlated (r = 0·95). Similar observations for feeds ranging from 0·14 to 0·25% phosphorus suggested that accurate prediction was also possible 144 h after infusion. Comparison of estimated feed phosphorus content of grazed material with that measured in hand-plucked herbage indicated that this approach is applicable to grazing studies.

scholarly journals Blood, intestinal and skeletal calcium dynamics during egg formation

1993 ◽  
Vol 73 (3) ◽  
pp. 517-532 ◽  
Author(s):  
M. Clunies ◽  
R. J. Etches ◽  
C. Fair ◽  
S. Leeson
Keyword(s):  
Half Life ◽  
Ovulatory Cycle ◽  
Left Femur ◽  
Period 2 ◽  
Individual Cage ◽  
Brachial Vein ◽  
Ovulatory Period ◽  
Post Intubation ◽  
The Right ◽  
Over Time

An experiment was carried out to study the dynamics of various body-Ca pools in the hen during a single ovulatory cycle. One hundred 32-wk-old Single Comb White Leghorn hens were used. For experimental purposes the ovulatory cycle was divided into four periods: 1–6, 6–12, 12–18 and 18–24 h post-oviposition.At 0, 6, 12 and 18 h post-oviposition 25 hens each were intubated proventricularly with 15 μCi of 45Ca as CaCl2 solution. Approximately 1 mL of blood was collected from the leaf brachial vein, and the bird was subsequently placed in an individual cage. Red blood cells, labelled with 15Cr, were re-injected into the same bird from which it was collected. At 0.5, 1, 2, 4 and 6 h post-intubation with 45Ca, blood samples were taken from the right brachial vein of five hens and the birds were immediately killed, carcasses were dissected, the left femur and tibia-fibula were excised, and an egg, if present, was removed. Whole blood was assayed for 51Cr activity, and plasma, bones and shells were assayed for 45Ca activity and Ca concentration.Another five hens were injected in the right brachial vein with 15 μCi of 45Ca immediately following oviposition. Subsequently, the left brachial vein was catheterized and blood was sampled at 0.5, 1, 2, 4, 6, 12, 18 and 24 h post-injection.There were no significant (P > 0.05) differences in blood volume or plasma-Ca concentration for the four periods assayed. Following intubation, plasma-45Ca activity decreased quadratically (P < 0.05) with time for all four periods assayed. Regression analysis showed that the biological half-life of plasma 45Ca was 3.30, 2.13, 1.80 and 1.77 h for periods 1, 2, 3 and 4 respectively. When birds were injected intravenously with 45Ca the half-life of plasma 45Ca was 0.116 h.There were no significant (P > 0.05) changes over time in ash or Ca content of bone ends (BE) or medullary bone (MB). Only MB accumulated 45Ca during the first 6 h of the cycle. There was no difference (P > 0.05) in 45Ca activity of either BE or MB over time in period 2. Only BE experienced a significant (P < 0.05) loss in 45Ca during period 4.There were no differences (P > 0.05) in total shell ash. shell Ca or 45Ca with time in period 1. Shell ash increased (P < 0.05) by 188, 348 and 237 mg h−1 and shell Ca increased by 69, 128 and 82 mg h−1 in periods 2, 3 and 4, respectively. Accumulation of shell 45Ca confirmed that the transfer of Ca was greatest during period 4 of the ovulatory cycle. Using 45Ca dynamics, we estimated that over the entire ovulatory period 1716 mg of Ca was absorbed from the digestive tract and 1704 mg was secreted as shell. Key words: Calcium-45 activity, calcium-45 half-life; plasma 45Ca, bone 45Ca, shell 45Ca, shell secretion, Ca absorption

scholarly journals Critical Variables to be Considered when Attempting to Estimate Blood Ethanol Concentrations in Rats from g/kg Exposure Data

2019 ◽  
Author(s):  
Carol A. Dannenhoffer ◽  
Dominika Hosová ◽  
Sanjeena Dang ◽  
Utkarsh Dang ◽  
Linda P. Spear ◽  
...  
Keyword(s):  
Intubation Time ◽  
Regression Analyses ◽  
Sample Collection ◽  
Elimination Phase ◽  
Knowing That ◽  
Exposure Data ◽  
Administration Time ◽  
The Individual ◽  
Post Intubation ◽  
Time Point

AbstractBackgroundIn rodent studies of ethanol (EtOH) consumption where blood sample collection does not occur, there is often mention of likely BECs based on prior studies. These studies may vary in dose(s) used, age/sex/species, or administration route. Often, intake studies may presume that binge-levels were achieved without knowing that BECs exceeded 80 mg% (binge threshold). In human studies, estimated BECs (eBECs) have been derived using complex formulas that consider EtOH consumption level and the weight and sex of the individual.MethodThree datasets were used to derive eBECs using a conversion factor (CF) that considers gram (g) of EtOH per kilogram (kg) of animal weight and other variables that may influence BECs such as age, sex, dose, route, vehicle, chronicity, and timing post-exposure. Regression analyses were also conducted for each dataset, building regression models with BEC as the response and other variables in the study specific to each dataset as predictor variables.ResultsDataset1 assessed age, sex and post-injection time point. Both CF and regression analyses determined that different CFs should be used for 10- and 30-min post-administration time points. Dataset2 assessed age, dose, vehicle and post-intubation time point. Depending on the post-intubation time point, several CFs were used to derive eBECs. When weight was not used as a regression variable, data across approaches corresponded, with age differences emerging later in elimination phase. In Dataset3 that used BECs from a repeated intake study, chronic exposure influenced CFs, although regression analysis did not yield similar findings.ConclusionsAlthough eBECs can be derived, critical variables vary with subject and test conditions and do not always concur with results of regression analyses. Although, not designed to replace assessment of BECs when sample collection is possible, the CF approach may prove useful when estimating BECs in studies where assessments are not feasible.

Effect of the concentration of estradiol and vitellogenin in the blood serum of meat and egg breed chickens on egg productivity

2022 ◽  
pp. 114-120
Author(s):  
O. Perinek ◽  
G. Shiryaev
Keyword(s):  
Blood Serum ◽  
Egg Yolk ◽  
Shape Index ◽  
The Body ◽  
Shell Formation ◽  
Ovulatory Cycle ◽  
Positive Correlation ◽  
Light Mode ◽  
Rare And Endangered ◽  
Egg Shell

The aim of the research is to determine the effect of changes in the concentration of estradiol-17β on the concentration of vitellogenin at the stage of egg shell formation and preparation of the body of meat and egg breed chickens (for example, the Pushkin breed) for ovulation.Materials and methods. The material for the study was the Pushkin breed chickens, in the amount of 28 heads. at the age of 48 weeks. Chickens were kept in individual cages. Light mode - 14C:10T. Drinking - nipple, temperature in the house and feeding - according to the standards adopted in the bioresource collection of RRIFAGB "Genetic collection of rare and endangered chicken breeds." Within 10 days prior to blood sampling, an ultrasound scan of the ovary and oviduct was performed from the studied group of chickens, which made it possible to determine the stage of egg formation. Blood from the studied chickens was taken in the morning on an empty stomach for the simultaneous determination of the concentration of estradiol and vitellogenin at the stage of egg shell formation. The concentration of estradiol and vitellogenin in the blood plasma of chickens was determined by ELISA. To clarify the effect of the concentration of estradiol (E2) on vitellogenin (VTG), the studied flock was divided into 2 groups according to the concentration of vitellogenin: 1st gr. – > Mav. (> 20 μg / ml) and 2nd gr. – < Mav. (<20 μg / ml). During the study period, eggs of chickens were evaluated according to the following morphometric parameters: the weight of the egg, yolk, protein and shell, elastic deformation, shape index, density of protein fractions, thickness of the shell and subshell, marbling. The number of eggs laid was determined in 10-day trial period.Results. It has been established that the duration of the ovulatory cycle in Pushkin breed chickens is 27-29 hours. As a result of such a long ovulatory cycle in the following days, laying of eggs occurs later with a progressive shift, as a result of which the laying cycle on average for the studied group of chickens is 3 days. The E2 level in the 1st group was 258,48 ± 30,60 pg/ml (p < 0,05), which significantly differed from the 2nd group – 181,45 ± 13,81 pg/ml. A positive correlation was found between VTG and E2, r = 0,5 (p < 0,001).Conclusion. The VTG level significantly increases in Pushkin chickens at the age of 48 weeks with an increase in the concentration of E2 in the blood. A positive correlation was noted between these features. According to the results of our research, the high content of estradiol and vitellogenin in the chickens blood serum did not have a significant effect on egg productivity.

EFFECTS OF INFLAMMATION ON PROTEINS AND ENZYMES IN RAT PLASMA

1960 ◽  
Vol 38 (6) ◽  
pp. 575-584 ◽  
Author(s):  
S. W. Levy ◽  
de Guise Vaillancourt
Keyword(s):  
Plasma Proteins ◽  
Specific Activity ◽  
Rat Plasma ◽  
Limb Volume ◽  
Significant Change ◽  
Plasma Esterase

The effects of anaphylactoid inflammation in rats on the limb volume, hematocrit, and plasma proteins, and on the activities of plasmin, antiplasmin, and esterase of the plasma were studied. The hyperemia and edema of the limbs and other extremities which occurred following the injection of dextran were found to be accompanied by a transient hemoconcentration and a prolonged depression in the concentration of plasma proteins (both albumin and globulin fractions). The specific activity of plasma esterase was increased and that of antiplasmin was decreased during inflammation compared with control animals. No consistent or significant change was observed in the specific activity of plasmin.

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