Effect of Organic or Inorganic Mineral Premix in the Diet on Laying Performance of Aged Laying Hens and Eggshell Quality.

In this study, we examined the effect of diets supplemented with organic and inorganic mineral premixes on the laying performance and eggshell quality of aged laying hens. A total of 600 68-week-old Hy-Line Brown laying hens were randomly assigned to 1 of 3 dietary treatments, repeated 5 times: Mash type basal diet, basal diet supplemented with an inorganic mineral premix (1.0 g/kg), and basal diet supplemented with an organic mineral premix (1.8 g/kg). The results showed that eggshell strength was higher ( p < 0.01) in the inorganic mineral diet group than in the organic mineral and basal diet groups. Further, the levels of Fe and Mn in the liver were higher ( p < 0.05) in the inorganic and organic mineral diet groups than in the basal diet group. The concentrations of Fe and Mg in the spleen were different ( p < 0.05) among the treatment groups, with the highest levels reported in the organic mineral premix group. The concentrations of Cu, Zn, and Mn in the eggshell were different ( p < 0.05) among the groups, with the highest levels reported in the inorganic and organic mineral premix diet groups. In conclusion, a diet containing organic mineral premix improved eggshell strength and had no detrimental effect on the laying performance of aged laying hens.