Embryo growth and amino acid concentration profiles of broiler breeder eggs, embryos, and chicks after in ovo administration of amino acids

Two experiments were conducted to evaluate the effect of in ovo amino acid (AA) injections in broiler breeder eggs on AA utilization of embryos. All A A used in these experiments were pure crystalline AA in free-base form. Tre atments in Experiment 1 comprised 1) control eggs (no injection), 2) 0.5 mL sterile-distilled water injected eggs, and 3) eggs injected with an AA sol ution suspended in 0.5 mL sterile-distilled water. Injections were administ ered into the yolk at Day 7 of incubation. At hatch, chicks were killed and bled, and plasma AA concentration was determined. Plasma AA concentration of hatched chicks decreased (P < 0.05) when water was injected. In addition , all AA from eggs injected with AA, except Glu and Lys, were decreased (P < 0.05) at hatch as compared to control eggs. However, AA pattern was not a ffected by in ovo water injection, but the AA ratio to Lys was reduced by i n ovo AA injection. Experiment 2 was conducted to evaluate whole internal egg AA concentrations over incubation time in the presence or absence of in ovo AA administratio n. Treatments in Experiment 2 comprised 1) control eggs (no injection), and 2) eggs injected with a AA solution at Day 7 of incubation. The AA content s of embryo, yolk, albumen, and allantoic and amnion fluids were analyzed o ver time during incubation (Days 0, 7, 14, and 19 of incubation). On Day 14 of incubation, there were no differences in AA contents of all tissues bet ween the control group and the group injected with AA on Day 7 of incubatio n. On Day 19 of incubation, AA contents of embryo, yolk, albumen, and allan toic and amnion fluids were increased (P < 0.05) as mediated by in ovo admi nistration of AA at Day 7 of incubation. These results suggest that in ovo administration of AA may increase AA concentrations in chicken embryos and other egg contents.