(Bioavailability and Effects of Reduced Inclusion Levels of Organic and Nano Zinc and Manganese on Albumen Quality in Laying Hen Diets)

This study aimed to investigate the effects of reduced inclusion levels of organic and nano forms of zinc and manganese on albumen quality in laying hens. A total of 162 LSL Classic laying hens, 30 weeks old, were distributed among nine dietary treatments in a 3 × 3 factorial arrangement, combining three sources of zinc and manganese (inorganic, organic, and nano). Inorganic zinc and manganese were provided at 60 and 100 mg/kg, respectively, while the organic and nano forms were reduced to 50% of the inorganic supplementation. Albumen quality traits were evaluated four times at 4-week intervals, and overall means were calculated for the entire experimental period. Organic and nano Zn, even at half the inorganic Zn inclusion, maintained albumen weight and their height (P > 0.05) during 16 weeks of feeding, and increased average Haug unit (P < 0.05). Reducing inclusion levels of organic and nano Mn did not affect albumen weight, percentage, height, and Haug unit (P > 0.05). The reduced inclusion combination of organic Zn and Mn achieved the best albumen weight and their height (P < 0.05) among all treatments; however, Haugh unit values were not affected by the interaction between Zn and Mn forms (P > 0.05). In conclusion, reducing the inclusion levels of organic and nano Zn and Mn by 50% can effectively maintain or even improve albumen quality compared with commercial levels of inorganic supplementation; however, the current data are still insufficient to support the definitive adoption of nano zinc and manganese.