In ovo feeding of Citrus aurantiifolia seed extract on hatchability, chick quality, physiological response, intestinal morphology and posthatch growth performance of cobb 500 broiler chickens

Abstract

This experiment was performed to evaluate the effect of in ovo injection of Citrus aurantiifolia seeds extract (CASE) into broiler incubating eggs. Five hundred and four (504) Cobb 500 breeder eggs with evidence of living embryos were selected for air chamber injection on embryonic d 18. The experimental treatments included control (without injection), Ext0.5µg (eggs injected with 0.5 μg/ml of CASE), Ext0.75µg (eggs injected with 0.75 μg/ml of CASE), Ext1µg (eggs injected with 1.0 μg/ml of CASE). After hatching, 360 chicks were distributed to their respective treatments with 6 replicates and raised for 6 wk in a completely randomized design (15 birds per replicate). The hatch events time decreased with increasing levels of CASE injection while at day old, the concentration of hematological parameters and chick quality score increased in all the in ovo injection treatments (P < 0.05). The injection of CASE at 0.5 µg/ml into the incubated eggs increased the weight of chicks at hatch and the ratio of the weight of chicks at hatch to the weight of the incubated egg (P < 0.001) and showed improved values of body weight gain and feed conversion ratio at 42 d. At hatch time, the injection of CASE showed a higher concentration of T4 (thyroxine) and a marked increase in plasma SOD (superoxide dismutase) activity compared to the control (P < 0.05). Additionally, CASE injection caused a significant improvement in the jejunal morphometry (P < 0.05). It was concluded that the in ovo injection of Citrus aurantiifolia seed extract during the prehatch period in broiler eggs is effective at 0.5 µg/ml.