title: Dietary calcium deficiency in laying ducks impairs eggshell quality by suppressing shell biomineralization.
abstract: The objective of this study was to determine the effects of dietary calcium deficiency on the process of shell formation. Four hundred and fifty female ducks (Anas platyrhynchos) at 22 weeks were randomly assigned to three groups. Ducks were fed one of two calcium-deficient diets (containing 1.8% or 0.38% calcium, respectively) or a calcium-adequate control diet (containing 3.6% calcium) for 67 days (depletion period) and then all ducks were fed a calcium-adequate diet for an additional 67 days (repletion period). Compared with the calcium-adequate control, the average shell thickness, egg shell weight, breaking strength, mammillae density and mammillary knob thickness of shell from ducks that consumed the diet with 0.38% calcium were significantly decreased (P<0.05) during the depletion period, accompanied by reduced tibia quality. The mRNA expression of both secreted phosphoprotein 1 (SPP1) and carbonic anhydrase 2 (CA2) in the uterus was decreased after feeding calcium-deficient diets (1.8% or 0.38% calcium). mRNA transcripts of calbindin 1 (CALB1), an important protein responsible for calcium transport, and the matrix protein genes ovocalyxin-32 (OCX-32) and ovocleidin-116 (OC-116) were reduced in ducks fed 0.38% calcium but not 1.8% calcium. Plasma estradiol concentration was decreased by both of the calcium-deficient diets (P<0.05). The impaired shell quality and suppressed functional proteins involved in shell formation could be reversed by repletion of dietary calcium. The results of the present study suggest that dietary calcium deficiency negatively affects eggshell quality and microarchitecture, probably by suppressing shell biomineralization.
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Zhi Mei
authors.initials: ZM
authors.lastname: Tian
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Han Xing
authors.initials: HX
authors.lastname: Zhang
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ruan
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China zhengcht@163.com lyc0123@tom.com.
authors.forename: Chun Tian
authors.initials: CT
authors.lastname: Zheng
authors.affiliation: Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China State Key Laboratory of Livestock and Poultry Breeding, Guangzhou 510640, China Key Laboratory of Animal Nutrition and Feed Science in South China, Guangzhou 510640, China Ministry of Agriculture Guangdong Public Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China Guangdong Key Laboratory of Animal Breeding and Nutrition, Guangzhou 510640, China zhengcht@163.com lyc0123@tom.com.
authors.forename: Ying Cai
authors.initials: YC
authors.lastname: Lin
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D064092:Calbindin 1 / Q000235:genetics / Q000378:metabolism; D002113:Calcification, Physiologic; D002118:Calcium / Q000172:deficiency* / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage*; D004372:Ducks / Q000033:anatomy & histology / Q000502:physiology*; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism; D004528:Egg Shell / Q000737:chemistry* / Q000648:ultrastructure; D004958:Estradiol / Q000097:blood; D005260:Female; D010058:Oviposition; D013977:Tibia / Q000473:pathology; D014599:Uterus
chemical_list: D064092:Calbindin 1; D002136:Calcium, Dietary; D004527:Egg Proteins; C439069:ovocalyxin 32; C402224:ovocleidin-116; D004958:Estradiol; D002118:Calcium
keywords: Calcium; Eggshell biomineralization; Eggshell microarchitecture; Laying ducks