Shell gland adenosine triphosphatase in hens producing strong and weak egg shells

Uterine Metabolomic Analysis for the Regulation of Eggshell Calcification in Chickens

Eggshell quality is economically important for table eggs and functionally indispensable for hatching eggs. During the formation of eggshell in the uterus, organic matrixes in uterine fluid can control and modify the formation of calcified eggshell. At present, there are limited studies focusing on the effect of uterine organic metabolites on eggshell quality. In this study, an LC-MS-based metabolomic technology was performed to identify the crucial uterine metabolites that differently presented in hens producing eggs with divergent eggshell quality (eggshell strength, thickness, and weight). More than 1000 metabolites were identified in uterine fluid, and six putative metabolites, including phosphatidylcholine, diacylglycerol, verapamil, risedronate, coproporphyrinogen III, and biliverdin, were screened to play crucial roles in eggshell calcification. Then, two trials for oral administration and in vitro calcite crystal growth were conducted to verify the effect of potential different metabolites on the eggshell quality. Verapamil has a temporary effect on decreasing eggshell strength and eggshell thickness. Coproporphyrinogen III could induce smaller calcite crystals to improve eggshell strength while biliverdin could modify crystal morphology by forming rougher faces and rounder edges to strengthen the eggshell. The present study gives us new insight to understand the role of uterine fluid matrixes in eggshell calcification.

The Effect of Different Levels of Dietary Magnesium on Eggshell Quality and Laying Hen's Performance

This study aimed to investigate the effects of different levels of dietary magnesium (Mg) on eggshell quality and laying hen's performance. Four dietary treatments including a commercial-type basal diet containing 3.19 g/kg Mg and three additional diets supplemented with 2, 4, or 6 g/kg magnesium oxide (MgO) to provide 4.03, 4.87, or 5.71 g/kg Mg were used in a completely randomized design. A total of 120 Bovans White layers at the age of 35 weeks were fed with dietary treatments for 8 weeks. Results indicated that increasing concentrations of Mg in the diets significantly increased hen-day egg production and feed intake (P < 0.05). Dietary Mg supplementation had no effect on egg weight, feed conversion ratio, and average daily weight gain. Eggshell weight, thickness, and strength were significantly increased by adding Mg to the diets (P < 0.05). Dietary treatments significantly increased yolk weight (P < 0.05) but decreased yolk color (P < 0.05). Albumen weight, Haugh unit, yolk shape, and egg shape index were similar among the dietary treatments. Eggshell Mg content (g/kg of dry matter) was significantly increased by the inclusion of Mg in the diets. In conclusion, the results of this study indicated that supplementation of Mg up to 5.71 g/kg diet improved eggshell quality and laying hen's performance.

Does my patient have a life- or limb-threatening thrombocytopenia?

The diagnosis and management of severe thrombocytopenias can be difficult, but is necessary to avoid significant morbidity and mortality. The causes of severe thrombocytopenias, often with a platelet count of less than 10 × 10(9)/L, include heparin-induced thrombocytopenia, the thrombotic microangiopathies, the catastrophic antiphospholipid syndrome, preeclampsia/HELLP, and posttransfusion purpura. This review provides a brief overview of the key clinical features of each of these major clinical entities, and strategies for their diagnostic workup and therapeutic management.

Effects of tri-o-cresyl phosphate on serum estrogen and progesterone concentration and ATPase activity in the shell gland of adult hens

The activities of calcium-activated ATPase (Ca2+-ATPase) and calcium magnesium-activated ATPase (Ca2+-Mg2+-ATPase) in the shell gland, and concentrations of 17beta-estradiol (E2) and progesterone in serum were monitored, respectively, from hens orally dosed with tri-o-cresyl phosphate (TOCP) (750 mg/kg). Treated birds were monitored daily for laying and development of delayed neurotoxicity, and activities of Ca2+-ATPase and Ca2+-Mg2+-ATPase were measured at 7 and 10 days after dosing. TOCP-treated birds manifested motor deficit by 7-9 days postdosing, while hens administered vehicle exhibited no signs of delayed neurotoxicity. Ca2+-ATPase and Ca2+-Mg2+-ATPase activities of shell glands from TOCP-dosed hens were not significantly affected (P > 0.05). The serum E2 concentration was significantly reduced in TOCP-treated hens (P < 0.01); however, progesterone levels were unaffected.

Calcium and carbonate supply in the shell gland of hens laying eggs with strong and weak shells and during and after a rest from lay

The concentration of calcium-binding protein (CaBP) and the activities of calcium adenosine triphosphatase (Ca(2+)-ATPase) and carbonic anhydrase (CA) were determined in the shell gland mucosa of hens in two experiments. In Experiment 1, laying hens on a proprietary layer mash were compared with hens rested from lay by the feeding of whole grain barley. In Experiment 2 comparisons were made of laying hens fed the proprietary layer mash and producing eggs with either strong or weak shells. These latter comparisons were also made when the shell gland was quiescent or active with respect to daily eggshell formation. Feeding whole grain barley reduced egg production to zero after 11 days. This reduction in rate of lay was accompanied by significant reductions in all three markers, the effect on Ca(2+)-ATPase and CaBP being less than for CA. Control values were regained between 10 and 16 days after the barley was replaced with the layer mash. Relative shell strength and the physiological status of the shell gland with respect to time of daily eggshell formation had no significant effect on any marker in Experiment 2.