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Volume 4, Issue 2 J Fisheries Livest Prod
ISSN: 2332-2608 JFLP, an open access journal
Page 61
Livestock Nutrition 2016
July 21-22, 2016
conferenceseries.com
July 21-22, 2016 Brisbane, Australia
2nd International Conference on
Livestock Nutrition
Calcium deficiency suppresses follicle growth in laying ducks
Wei Chen1, Z M Tian2, X Luo2, F Zhao3, D Ruan3, S L Wang, S Wang, C T Zheng5 and Y C Lin5
1Guangdong Academy of Agricultural Sciences, China
2State Key Laboratory of Livestock and Poultry Breeding, China
3Key Laboratory of Animal Nutrition and Feed Science in South China, China
4Ministry of Agriculture, China
5Guangdong Key Laboratory of Animal Breeding and Nutrition, China
C alcium is very important for maintaining the bone growth and eggshell formation in laying birds. However, some of other
biological functions of calcium in laying birds are scarcely known. The purpose of this study was to test the hypothesis that
calcium may affect the follicle growth of laying ducks by employing calcium-deficient diet. 450 female ducks (Anas platyrhynchos)
of 22 weeks were randomly assigned to 3 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 ducks of
the 3 groups were fed a calcium-adequate diet for an additional 67 days (repletion period). As compared with the calcium-adequate
control, the hierarchical ovarian follicles number (diameter >1 cm) and total ovary weight of ducks that consumed the diet with
0.38% calcium was significantly decreased (P<0.05) during the depletion period, accompanied by reduced egg production. The
mRNA expression of ovary gap junction protein, alpha 1 (GJA1), gamma 1 (GJC1), delta 2 (GJD2) were decreased after feeding
calcium-deficient diets (1.8% or 0.38% calcium, P<0.05). Transcripts of estradiol receptor 2 (ER2), luteinizing hormone receptor
(LHR) in ovary were reduced in the ducks fed 0.38% calcium or 1.8% calcium (P<0.05). While the mRNA expression of ovary follicle
stimulating hormone receptor (FSHR) was decreased in the ducks fed 0.38% calcium but not the 1.8% calcium. The cAMP content in
the ovary was increased by calcium depletion (the increase reached 6% for 1.8% calcium and 13% for 0.38% calcium, respectively).
Plasma concentrations of estradiol, follicle stimulating hormone (FSH) and calcium was decreased by both of the calcium-deficient
diets (P<0.05). The down-regulated gene expression of gap junction protein, hormone receptor, increased cAMP content as well as
the suppressed follicle growth could be reversed by repletion of dietary calcium. The results of the present study suggest that dietary
calcium deficiency negatively affects the follicle growth of laying ducks possibly by down-regulating follicle growth-related genes and
hormones.
J Fisheries Livest Prod 2016, 4:2 (Suppl)