Intra-Amnionic Threonine Administered to Chicken Embryos Reduces Enteritidis Cecal Counts and Improves Posthatch Intestinal Development.

This study assessed the effect of threonine supplementation on the response of broiler chicks challenged with Enteritidis, considering bacterial counts in cecal contents, intestinal morphology, body weight, and weight gain. Fertilized eggs were inoculated in the amniotic fluid with saline (NT) or 3.5% threonine (T) solution at day 17.5 of incubation. At hatch, chicks were individually weighed and cloacal swabs were screened for . At 2 days of age, half of the birds from each treatment were given either 0.5 mL of nutrient broth (sham-inoculated) or nalidixic acid-resistant Enteritidis (SE Nal) in nutrient broth (8.3 × 10 colony forming units (CFU) SE Nal/mL). The birds were distributed using a completely randomized design with four treatments after the challenge: no Thr supplementation and sham-inoculated in the posthatch challenge (NT-SHAM), Thr supplementation and sham-inoculated (T-SHAM), no Thr supplementation and SE Nal-challenged (NT-SE), and Thr supplementation and SE Nal-challenged (T-SE). threonine supplementation reduced Enteritidis colonization 168-hour postinoculation and reduced the negative effects associated with infection on intestinal morphology and performance, with results similar to those of the sham-inoculated birds. Thr supplementation increased the expression of at hatch and the expression of and at 2 days of age and 168-hour postinoculation. Our results suggest that providing threonine promotes intestinal health in broilers challenged with Enteritidis in the first days of life.