Effect of Manganese Levels and Sources on Performance of Laying Hens
An experiment was conducted to study the effects of different manganese levels and sources on performance of laying hens.The results showed that there were no significant differences in feed intake,total egg weight, egg production or average egg size among different manganese levels when the basal diet was supplemented with Mn from either MnSO 4·H 2O or Mn Met (P0 05). There were no marked differences between MnSO 4·H 2O and Mn Met as well (P0 05). When manganese source was MnSO 4·H 2O,different manganese levels had no significant effect on feed egg ratio (P0 05).But manganese source was Mn Met and dietary supplemental manganese increased from 0 to 120 mg/kg, feed egg ratio was reduced markedly (P0 05),and there was also obvious difference compared with MnSO 4·H 2O.The dietary manganese deficiency (31 91 mg/kg Mn) resulted in the increase of the percentages of malformal, soft and broken eggs significantly (P0 05 or P0 01). The percentages of malformal,soft and broken eggs were decreased significantly as dietary supplemental manganese increased from 0 to 60 mg/kg (P0 05 or P0 01), and the effect of Mn Met improving egg shell quality was better than that of MnSO 4·H 2O.