Organic Trace Mineral Levels in the First 96-H Post-Hatch Impact Growth Performance and Intestinal Gene Expression in Broiler Chicks

Alterations in nutrient intake in the avian neonatal post-hatch period can impact development, performance, and metabolism in adulthood. Very little is known about how mineral levels during the post-hatch period affect or "program" gene expression patterns later in life. The objective of this study was to determine the effect of post-hatch (0 to 96 h) dietary mineral supplementation on performance, tissue mineral content, and intestinal gene expression profiles in 21-day-old broiler chicks. One-day-old chicks were randomly assigned to one of two treatment groups consisting of N (organic Zn, Cu, and Mn provided at 100 % of recommendations (National Research Council 1994)) and/or L (organic Zn, Cu, and Mn provided at 20 % of recommendations (National Research Council 1994)) diets fed in two intervals (days 1-4, days 5-21) as follows: (1) N-L or (2) L-L. Performance parameters did not differ between treatments except that body weight gain was greater (P < 0.05) in L-L birds than N-L birds over the experimental period. Bone mineral content was similar for both treatments at day 21. Intestinal gene expression profiling was examined using the Affymetrix GeneChip Chicken genome array. Ingenuity pathway analysis revealed differences in gene expression profiles between N and L treatments at day 5. At day 21, profiles were unique between N-L and L-L, suggesting that the diet fed until day 4 had an impact on gene expression patterns at day 21 even when birds were fed the same diets day 5-day 21. In this study, we demonstrated that diets fed for the 96 h post-hatch had long-term effects on gene expression, providing unique information as to why post-hatch diets are so important for the long-term bird health and productivity.