Estimation of dietary manganese requirement for laying duck breeders: effects on productive and reproductive performance, egg quality, tibial characteristics, serum biochemical and antioxidant indices

Abstract This study was aimed at estimating the dietary manganese (Mn) requirement for laying duck breeders. A total of 504 Longyan duck breeders (body weight: 1.20 ± 0.02 kg) aged 17 wk were randomly allocated to 6 treatments. The birds were fed a basal diet (Mn, 17.5 mg/kg) or diets supplemented with 20, 40, 80, 120 or 160 mg/kg Mn (as MnSO4·H2O) for 18 wks. Each treatment had 6 replicates of 14 ducks each. As a result of this study, dietary Mn supplementation did not affect the productive performance of laying duck breeders in the early laying period (17 to 18 wk), but affected egg production, egg mass and feed conversion ratio (FCR) from 19 to 34 wk (P