Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “eggshell”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1993

Effect of dietary contents of cholecalciferol, 1 alpha,25-dihydroxycholecalciferol and 24,25-dihydroxycholecalciferol on blood concentrations of 25-hydroxycholecalciferol, 1 alpha,25-dihydroxycholecalciferol, total calcium and eggshell quality.

1. Withdrawal of cholecalciferol (D3) supplement from a layers diet drastically reduced blood 25-hydroxycholecalciferol (25-OH-D3), 1 alpha,25-dihydroxycholecalciferol (calcitriol) and egg specific gravity (SG) within two weeks, followed by a decrease in blood total calcium (Ca). 2. Doubling the D3 supplement in the control diet (27.5 micrograms or 1100 IU/kg) almost linearly increased the circulating concentration of 25-OH-D3 without raising the concentration of calcitriol, Ca, or egg SG. 3. Replacing D3 by the optimal concentration of calcitriol (5 micrograms/kg diet) improved egg SG after 21 weeks of treatment without increasing blood calcitriol or total Ca. 4. By itself, 24,25-dihydroxycholecalciferol [24,25-(OH)2D3] was unable to maintain normal blood levels of calcitriol, Ca or egg SG and, when added together with calcitriol in the diet, tended to elevate blood Ca but suppress the beneficial effect of calcitriol on shell quality, with little or no effect on blood calcitriol.

24,25-Dihydroxyvitamin D 3↗
PubMed1998

Effects of age at onset of production, light regime and dietary calcium on performance, eggshell traits, duodenal calbindin and cholecalciferol metabolism.

1. Rate of production and shell thickness (ST) decreased, while body weight (BW), egg weight (EW) and percentage breakage increased progressively with age. Shell weight (SW) increased until 8 to 13 months of age and then decreased. 2. Early onset of production resulted in lower BW and EW at the onset of production, and lower pooled averages of BW, EW, SW and ST, as compared with late or medial onset of production. In 4 out of 5 trials, early onset did not result in the production of more eggs during the laying period. 3. Early onset of production is associated with physiological Ca deficiency as indicated by increases in kidney-1-hydroxylase and duodenal calbindin in early layers as compared with late layers. Early layers exhibited a more severe reduction in shell quality as the result of Ca deficiency as compared with late layers. 4. Feeding pullets with a prelaying diet containing 3.9% Ca did not affect unequivocally the performance or shell quality during the whole productive period, whether the birds started to lay early or late. The dietary treatment did not cause renal damage, as indicated by morphological examination and by plasma calcium and uric acid concentration.

Age Factors↗
PubMed1990

Genetic analysis of two female-sterile loci affecting eggshell integrity and embryonic pattern formation in Drosophila melanogaster.

We have analyzed female-sterile mutations at the X-linked loci fs(1)Nas and fs(1)ph which show allele-specific effects on egg shell structure and embryonic pattern formation. The majority of mutant alleles at both loci lead to a collapsed egg phenotype. The maternal effect lethal phenotype is characterized by cuticle defects resembling those found in three autosomal mutants of the terminal class. We have analyzed the complementation behavior of various heteroallelic combinations at both loci and show that one such combination at the fs(1)Nas locus is capable of restoring normal fertility. We have investigated possible interactions between fs(1)Nas and fs(1)ph and also between the terminal allele of fs(1)Nas and various maternal effect mutations altering the anteroposterior polarity of embryos. We have isolated one new allele of fs(1)Nas which combines the locus-typical phenotypic features with novel cuticle phenotypes. Our results suggest that the products of fs(1)Nas and fs(1)ph are required for the stability of the vitelline membrane and are also involved in a morphogenetic pathway necessary for the correct differentiation of the terminal regions of the embryo. Possible mechanisms to account for the association of these two functions are discussed.

Alleles↗
PubMed1971

Eggshell thinning in Japanese quail fed mercuric chloride.

The eggs produced by developing Japanese quail (Coturnix coturnix japonica) fed 1 to 8 parts of mercury per million as mercuric chloride for 10 weeks have thinned shells. Total amounts of mercury in tissues were quite proportional to the dosage and were higher in males than in females. Methylation of mercury was not observed.

Animals↗