scholarly journals Osteoclast cell-surface changes during the egg-laying cycle in Japanese quail

1977 ◽  
Vol 75 (1) ◽  
pp. 104-118 ◽  
Author(s):  
SC Miller
Keyword(s):  
Cell Surface ◽  
Japanese Quail ◽  
Bone Cells ◽  
Egg Laying ◽  
Medullary Bone ◽  
Cell Processes ◽  
Cyclic Variations ◽  
Egg Shell ◽  
Cell Surface Changes ◽  
Cyclic Changes

The medullary bone serves as a source of labile calcium mobilized during calcification of the egg shell in birds. Quantitative histological methods demonstrate that the numbers of medullary bone osteoclasts and nuclei per osteoclast remain unchanged during the egg cycle in the Japanese quail (Coturnix). Therefore, cyclic changes in bone resorption cannot be explained by modulations of osteoclasts from and into other bone cells, a mechanism previously suggested for certain species of birds. Rather, dramatic changes in osteoclast cell-surface features occur during the egg cycle, which might account for cyclic variations in resorptive activity. During egg shell calcification, osteoclasts with ruffled borders are closely apposed to bone surfaces; the cytoplasm is rich in vacuoles that contain mineral crystals and seem to derive from the ruffled border. At the completion of egg shell calcification, the ruffled borders and vacuoles move away from the bone surface, although the osteoclast remains attached to the bone along the filamentous or "clear" zone. Associated with the disappearance of the ruffled borders is the appearance of extensive interdigitated cell processes along the peripheral surface of the osteoclast away from the bone. These unusual structures, which may serve as a reservoir of membrane, largely disappear when ruffled borders and associated structures reappear. Therefore, in these hens, the osteoclasts modulate their cell surface rather than their population during the egg cycle.

Vitamin D metabolism: physiological regulation in egg-laying Japanese quail

1976 ◽  
Vol 230 (6) ◽  
pp. 1609-1615 ◽  
Author(s):  
AD Kenny
Keyword(s):  
Japanese Quail ◽  
Vitamin D3 ◽  
Physiological State ◽  
Reproductive Period ◽  
Egg Laying ◽  
Ovulatory Cycle ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D3 ◽  
Enhanced Production ◽  
Egg Shell

Homogenates of kidney removed from reproductivity active female Japanese quail were incubated with tritiated 25-hydroxyvitamin D3, and the metabolites were extracted and identified by chromatographic methods. Kidneys removed from birds with and without an egg in the oviduct revealed that ovulation results in enhanced production of 1, 25-dihydroxyvitamin D3, the active hormonal form of vitamin D3. Further examination of this phenomenon in relation to the ovulatory cycle revealed that 1, 25-dihydroxy-vitamin D3 production is enhanced throughout the 24 h following ovulation. Particularly important is the finding that its synthesis is already enhanced during the first 6 h after ovulation, at a time before any calcification of the egg shell begins. If, following oviposition, no ovulation occurs, 1, 25-dihydroxy-vitamin D3 production decreases rapidly and significantly within the first 6 h following oviposition. This study has revealed for the first time a physiological state, namely the reproductive period in the female bird, in which endogenous control over 1, 25-dihydroxyvitamin D3 production is exhibited without any previous manipulation, dietary or otherwise, of the animals.

PARATHYROID HORMONE AND EGGSHELL CALCIFICATION IN JAPANESE QUAIL

1976 ◽  
Vol 71 (2) ◽  
pp. 239-243 ◽  
Author(s):  
C. G. DACKE
Keyword(s):  
Parathyroid Hormone ◽  
Japanese Quail ◽  
Unit Area ◽  
Egg Laying ◽  
Target Organ ◽  
Shell Weight ◽  
Parathyroid Extract ◽  
Egg Shell ◽  
Subsequent Incorporation

SUMMARY The effect of parathyroid hormone (PTH) on egg-shell calcification has been investigated in egg-laying Japanese quail. Lilly parathyroid extract (PTE) when injected into quail within 2–6 h of oviposition caused a significantly increased deposition of a chronic 45Ca label into the sequential egg-shell compared with the previous egg in the clutch, indicating increased mobilization of bone Ca and its subsequent incorporation into the egg-shell. At the same time egg-shell weight/unit area and egg-shell Ca/unit area were significantly decreased. Parathyroid extract injected 12–16 h after oviposition had none of these effects. Purified PTH also caused a significant decrease in egg-shell weight/unit area if injected within 2–6 h of oviposition. This result indicated an action of PTH either directly or indirectly on the avian oviduct limiting egg-shell calcification. The loss of responses in the 12–16 h treated birds may reflect high endogenous PTH levels with subsequent saturation of target organ receptors.

scholarly journals The metabolism of cholecalciferol in the liver of Japanese quail (Coturnix coturnix japonica) with particular reference to the effects of oestrogen

1979 ◽  
Vol 182 (3) ◽  
pp. 745-750 ◽  
Author(s):  
R A Nicholson ◽  
M Akhtar ◽  
T G Taylor
Keyword(s):  
Japanese Quail ◽  
Egg Laying ◽  
Water Soluble ◽  
Coturnix Japonica ◽  
Coturnix Coturnix ◽  
Polar Metabolites ◽  
Liver Homogenates ◽  
Egg Shell ◽  
25 Hydroxycholecalciferol

1. Studies were carried out in vitro with the livers of Japanese quail that had been fed from hatching on diets supplying their full requirements for vitamin D. 2. 25-Hydroxycholecalciferol was the major metabolite when liver homogenates of egg-laying female and oestrogen-treated quail of both sexes were incubated with [3H]cholecalciferol. 3. Very little 25-hydroxycholecalciferol was generated from liver homogenates of adult male and immature quail. Instead the cholecalciferol was converted into one or more compounds less polar than 25-hydroxycholecalciferol and into a number of highly polar metabolites, some of which were water-soluble. 4. Oestrogen not only stimulated the 25-hydroxylation of cholecalciferol but also protected both cholecalciferol and 25-hydroxycholecalciferol from degradation by the enzymic pathways active in immature and male birds. 5. These actions of oestrogen may be of physiological significance in relation to the high requirements of laying birds for 1,25-dihydroxycholecalciferol to support the intense metabolism of calcium associated with egg-shell calcification.

The role of vitamin D in the medullary bone formation in egg-laying japanese quail and in immature male chicks treated with sex hormones

1983 ◽  
Vol 35 (1) ◽  
pp. 465-471 ◽  
Author(s):  
Naoyuki Takahashi ◽  
Toshimasa Shinki ◽  
Etsuko Abe ◽  
Noboru Horiuchi ◽  
Akira Yamaguchi ◽  
...  
Keyword(s):  
Vitamin D ◽  
Bone Formation ◽  
Sex Hormones ◽  
Japanese Quail ◽  
Egg Laying ◽  
Medullary Bone ◽  
Immature Male

scholarly journals Dual-Purpose Poultry in Organic Egg Production and Effects on Egg Quality Parameters

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 897
Author(s):  
Marianne Hammershøj ◽  
Gitte Hald Kristiansen ◽  
Sanna Steenfeldt
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Quality Parameters ◽  
Egg Laying ◽  
High Yield ◽  
Meat Production ◽  
Dual Purpose ◽  
Shell Quality ◽  
Egg Shell ◽  
Genotype A

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Three dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, genotype B was a pure breed, and genotype C was a crossbreed of a layer type. These were compared to a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 1080 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.

scholarly journals Effect of Age on Bone Structure Parameters in Laying Hens

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 570
Author(s):  
Masayoshi Yamada ◽  
Chongxiao Chen ◽  
Toshie Sugiyama ◽  
Woo Kyun Kim
Keyword(s):  
Cortical Bone ◽  
Bone Quality ◽  
Bone Mineral ◽  
Volume Fraction ◽  
Bone Structure ◽  
Bone Volume ◽  
Egg Laying ◽  
Medullary Bone ◽  
Mineral Density ◽  
Tibial Diaphysis

Changes in medullary and cortical bone structure with age remain unclear. Twenty Hy-Line W36 hens, 25 or 52 weeks of age, were euthanized, and both tibiae were collected when an egg was present in the magnum. Serial cross sections of the tibiae were stained with Alcian blue. The bones were scanned using micro-computed tomography. Trabecular width (Tb.Wi) was significantly higher (p < 0.05) in 25-week-old hens, whereas medullary bone tissue volume (TV) was significantly higher (p < 0.01) in 52-week-old hens. 25-week-old hens had significantly higher (p < 0.01) bone volume fraction (BVF = calcified tissue / TV). Moreover, the cortical bone parameters were significantly higher (TV and bone mineral content (BMC) at p < 0.05, and bone volume (BV) and BVF at p < 0.01) in younger hens. Open porosity and total porosity, which indicate less density, were significantly higher (p < 0.01) in older hens. Older hens showed significantly higher (p < 0.01) tibial diaphysis TV than younger hens. Younger hens had significantly higher (p < 0.01) BV, BVF and bone mineral density (BMD) of the tibial diaphysis. These findings reveal that reductions in medullary bone quality might be associated with age-related low estrogen levels and stimulation of osteoclastic bone resorption by parathyroid hormone. Cortical bone quality decreased with enlargement of the Haversian canals and loss of volume, with a longer egg-laying period leading to osteoporosis.

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