Effects of dietary organic and inorganic manganese supplementation on performance, egg quality and bone mineralisation in laying hens

摘要

The aim of this study was to investigate the effects of different dosages of organic and inorganic manganese supplementation into diets on performance,egg quality and bone mineralization in laying hens. One hundred and fifty,49 weeks old, H&N Brown Nick laying hens were assigned to 10 equalgroups according to the diet regimen consisting in standard diet (based oncorn and soybean meal) supplemented with Mn inorganic (Mn-sulphate) ororganic (Mn-Bioplex) sources at 5 increasing doses (15, 30, 45, 60 and 75mg/kg) for 12 weeks. Compared to the inorganic form, the Mn-Bioplex supplementation has significantly increased the body weight gains and the eggweight and reduced the percentage of damaged eggs. In parallel, the tibia cortex thickness and its cross area section were significantly enhanced, leadingto a slight improvement in bone resistance. The bone proportions of mineralCa and P elements have significantly increased according to the Mn dosesbut were not significantly affected by the Mn forms whereas the Mg percentagewas significantly depressed with Mn-Bioplex. The tibial contents of Zn andCu were maximal when low doses of Mn, mainly as Mn-sulphate, were usedwhereas the Mn accumulation in bone was mainly observed when Mn-Bioplexwith doses above 30 mg/kg were used. These results sustained that organicMn form supplementation positively affects the element distribution in theorganism leading to improvement in the weight growth, the egg weight andin the bone solidity in laying hens.