Effects of Different Patterns and Sources of Trace Elements on Laying Performance, Tissue Mineral Deposition, and Fecal Excretion in Laying Hens

SIMPLE SUMMARY: This study aims to investigate the effects of laying performance, tissue mineral deposition, and fecal excretion from laying hens fed dietary treatments with different patterns and sources of trace elements including zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), and selenium (Se). A total of 864 healthy laying hens with similar laying rate (Roman, 26-week-old) were randomly divided into nine treatments, with six replications of 16 birds per replication, including a control treatment (basic diet without added extra trace minerals) and four patterns with different element sources (inorganic mineral or organic mineral): 1. NRC (1994) recommended level pattern (NRC-L pattern); 2. NY/T 33-2004 recommended level pattern (NY/T-L pattern); 3. 50% NRC (1994) recommended level (50% NRC-L pattern); 4. the ratio of minerals in the blood of laying hens was taken as the supplement proportion of trace elements, and Zn was supplemented depended on the NRC recommended level pattern (TLB pattern). The results indicated that supplemental trace elements improved laying rate, liver, kidney, pancreas, spleen, pectorals muscle, and tibia mineral concentrations (Zn, Fe, Cu, Mn, Se). Patterns affected the tissue and fecal mineral concentrations. In addition, supplementation of the minerals with organic trace elements increased tissues and fecal mineral concentration than those with inorganic minerals. In conclusion, diet supplemented with the organic trace minerals of 50% NRC-L pattern for laying hens promoted optimum laying performance, mineral deposition, and reduced mineral excretion. ABSTRACT: This study was conducted to investigate the effects of different patterns and sources of Zn, Fe, Cu, Mn, and Se on performance, mineral deposition (liver, kidney, pancreas, spleen, pectorals muscle, and tibia), and excretion of laying hens, then to find an optimal dietary supplemental pattern of trace elements in laying hens. A total of 864 healthy laying hens with similar laying rate (Roman, 26-week-old) were randomly divided into nine treatments, with six replications of 16 birds per replication, including a control treatment and four patterns with different element sources (inorganic or organic): (1) Control treatment (basic diet without added extra trace minerals, CT); pattern 1, NRC (1994) recommended level (NRC-L): (2) inorganic minerals of NRC-L pattern (IN), (3) organic minerals of NRC-L pattern (ON); pattern 2, NY/T 33-2004 recommended level (NY/T-L): (4) inorganic minerals of NY/T-L pattern (IY), (5) organic minerals of NY/T-L pattern (OY); pattern 3, 50% NRC (1994) recommended level (50% NRC-L): (6) inorganic minerals of 50% NRC-L pattern (IHN), (7) organic minerals of 50% NRC-L pattern (OHN); pattern 4, the ratio of minerals in blood of laying hens was taken as the supplement proportion of trace elements, and Zn was supplemented depended on NRC recommended level (TLB): (8) inorganic minerals of TLB pattern (IB), (9) organic minerals of TLB pattern (OB). Two weeks were allowed for adjustment to the conditions and then measurements were made over eight weeks. Supplementation of trace elements led to increased daily egg weight (p < 0.05). Patterns of minerals in diets affected the content of liver Mn, pancreas Mn, tibia Mn, and the tissues Se (p < 0.05). Sources of minerals had positive effects on daily egg weight (p < 0.05), the concentrations of liver Fe, kidney Cu, tissues Se (except spleen), and fecal Se (p < 0.05). In conclusion, diet supplemented with the organic trace minerals of 50% NRC-L pattern (OHN) in laying hens promoted optimum laying performance, mineral deposition, and reduced mineral excretion.