In ovo trace element supplementation enhances expression of growth genes in embryo and immune genes in post-hatch broiler chickens

BACKGROUND: Differential expression of growth-and immunity-related genes and post-hatch performances were evaluated in in ovo zinc (Zn), iodine (I) or selenium (Se) supplemented chicken embryos. RESULT: There was about 9-18% reduction in hatchability of Zn, I or Se supplemented eggs. In ovo trace element supplementation did not improve post-hatch growth. Two-way analysis of data revealed significant effect (P > 0.01) of period, trace elements and their interactions. Expression of hepatic somatotropin, insulin-like growth factor-II and mucin gene was highest at 20th embryonic day but decreased during post-hatch periods. In ovo Zn or I supplemented embryos had higher expression of growth-related genes compared to the Se or un-injected control group. Expression of interleukin-6 was higher (P < 0.01) in in ovo I supplemented chicks (2.5-fold) but lower in the Zn and Se groups than in the un-injected control group. However, Zn and Se supplemented chicks had higher cellular immune gene expression. In vivo response to mitogen phytohaemaglutinin was also higher (P < 0.01) in Zn or Se supplemented chicks CONCLUSION: In ovo supplementation of Zn, I and Se did not improve the post-hatch growth, but increased growth-related gene expression. Iodine improved humoral immune gene expression whereas Zn and Se enhanced cell-mediated immune gene expression in broiler chickens. (c) 2015 Society of Chemical Industry