Effects of the in ovo feeding of Lactobacillus on the hatch percentag, growth performance, carcass characteristics, and immune response of broilers

Abstract

Introduction: This experiment was conducted to study the effects of the in ovo feeding of Lactobacillus on the hatch percentag, growth performance, carcass characteristics, and immune response of broilers. Materials & Methods: This experiment was conducted using 240 fertilized eggs from broiler in three treatments, four replicates and 20 eggs per each replicate with completely randomized design. The experimental treatments were included non-injected (control), injected with 0.1 mL of distilled water, and injected with 0.1 mL of Lactobacillus with a concentration of 105 CFU/gr. On the 18th day of incubation, the position of the amniotic fluid of the eggs was determined using the candling method and then 0.1 mL of the experimental solution was injected using a syringe with a 22-gauge needle into the amniotic fluid of the fertile eggs. The injection spot was blocked with paraffin after injection, and the eggs were immediately transferred to the hatcher. All chickens in different treatments were freely fed with a common experimental diet. Results: The in ovo feeding of Lactobacillus caused a significant increase in hatchability compared to the group injected with distilled water and the control group (P<0.05). Injecting Lactobacillus increased significantly the weight of day-old chicks compared to distilled water injection (P<0.05). Injecting distilled water or Lactobacillus had no significant effect on feed intake, daily weight gain, and feed conversion ratio in different periods of rearing (P>0.05). Injecting Lactobacillus did not have significant effect on the relative weight of carcass, thigh, breast, abdominal fat, bursa, and thymus of chickens (P>0.05). Compared to the group injected with distilled water, Lactobacillus injection caused a significant decrease in intestinal pH (P<0.05). With Lactobacillus injection, antibody titer against Newcastle disease and influenza at the age of 42 days increased significantly compared to distilled water injection or the control group (P<0.05). Conclusion: According to the results of the present experiment, in ovo feeding of Lactobacillus could improve hatchability, weight of day-old chicks, and immune responses of broiler chickens.