The effect of inoculating Enterococcus faecalis into the yolk sac on chick quality and maternal antibody absorption

Four hundred thirty-two 1-day-old specific-pathogen-free chicks were randomly divided into 36 groups of 12. All chicks were given 0.2 ml of Newcastle disease antiserum (hemagglutination-inhibition [HI] titer 1:5120) by injection into the yolk sac at hatch. Half of the groups received 0.2 ml of Enterococcus faecalis (4.0 x 10(8) colony-forming units/ml) by injection into the yolk sac at hatch (treatment). The remaining 18 groups received no bacteria (control). Two treatment groups and two control groups were weighed, bled, killed, and yolk sac weighed daily for the first 9 days of life. Feed was weighed at placement and at the end of the trial. Blood was tested for packed cell volume (PCV), total plasma protein, and Newcastle disease HI titer. No significant difference was observed between treatment and control groups for chick body weight, PCV, and feed consumption. Total plasma protein and retained yolk weight were significantly higher for treatment groups over control (P < 0.01 and P < 0.0001, respectively). Also, the geometric mean serum HI titer (log2) for Newcastle disease antibody was significantly higher in the control chicks vs. the treatment chicks (P < 0.01).