Vitellogenin-Dynamics-and-Reproductive-Morphology-at-Sexual-Maturity-of-Philippine-Mallard-(Anas-platyrhynchos-domesticus-L)-Fed-with-Zinc-Die- Vitellogenin-Dynamics-and-Reproductive-Morphology-at-Sexual-Maturity-of-Philippine-Mallard-(Anas-platyrhynchos-domesticus-L)-Fed-with-Zinc-Die-