Effects of in ovo injection of electrolyte solutions on the pre- and posthatch physiological characteristics of broilers.

Effects of the automated in ovo injection of various concentrations and volumes of physiological electrolyte solutions and a carbohydrate-electrolyte solution (CEN) on broiler embryo development and posthatch chick performance were investigated in 5 individual consecutive trials to test potential diluents for commercial injection. A 200-µL saline solution (117 mM) injection treatment and a noninjected control were included in all trials. For the first 4 trials, solutions were injected into the amnion of embryos on d 16 of incubation, and subsequent percentage incubational egg weight loss, embryo mortality, proportional embryo BW, embryo moisture content, proportional yolk sac weight, and yolk moisture content were evaluated on d 18. In trial 5, solutions were injected into the amnion on d 18, and subsequent hatchability and posthatch performance were investigated. In trial 1, a 200-μL injection of 5 mM tripotassium citrate (C(6)H(5)K(3)O(7)) and a 200-μL injection of CEN at 1:400 and 1:8,000 concentrations had no detrimental effect on proportional embryo BW. However, embryo moisture content was increased by the injection of either solution at all concentrations. In trial 2, 200-μL injections of saline, potassium chloride (KCl), or sodium dihydrogen phosphate (NaH(2)PO(4)) solution at various physiological concentrations did not affect any of the parameters examined. In trial 3, the injection of 2,000 µL of 117 mM saline reduced 0 to 18 d percentage egg weight loss. In trial 4, percentage egg weight loss was reduced and embryo moisture was increased by a 200-μL saline (117 mM) injection, but not by 200 μL of solutions of CEN (1:400), C(6)H(5)K(3)O(7) (5.0 mM), or NaH(2)PO(4) (1.0 mM) in 5.5 mM KCl. Compared with controls in trial 5, plasma refractive index was increased by CEN-KCl (1:400-5.5 mM) and saline (117 mM) injections, but not by C(6)H(5)K(3)O(7)-KCl (5 mM-5.5 mM). The current study indicated that 5.5 mM KCl and 5 mM C(6)H(5)K(3)O(7) have the greatest potential for use individually or in combination for the commercial injection of broiler hatching eggs.