Effects of dietary organic or inorganic manganese, zinc, copper and chrome supplementation on the performance, egg quality and hatching characteristics of laying breeder hens

This study was conducted to compare the effects of organic or inorganic Mn, Zn, Cu and Cr mixture using two different levels (80, 60, 5 and 0.15 mg/kg and 40, 30, 2.5 and 0.07 mg/kg, respectively) on the performance, egg quality and hatching characteristics of laying breeder hens. The experiment began with a total of 360 hens from Barred Rock line at 50 weeks of age and continued for 16 weeks. Each of the four dietary treatments was randomly assigned to six replicates, which included 15 hens each. Different trace mineral applications did not result in a significant effect on performance parameters such as livability, body weight gain, egg production, egg weight and mass, feed intake, and feed conversion. No significant differences in egg quality parameters such as damaged egg rate, shape index, eggshell rate and thickness, albumen height and haugh unit were observed among the groups. However, the low level of trace minerals resulted in a significant reduction in eggshell breaking strength (P < 0.05). Different trace mineral applications did not show a significant effect on hatching and fertilised eggs ratio. The dietary supplementation of organic (chelated with methionine) Mn, Zn, Cu and Cr at high levels (80, 60, 5 and 0.15 mg/kg, respectively) increased the hatchability of the fertilised eggs and hatchability compared to that of the other groups (P < 0.05).