Effects of in ovo Ocimum gratissimum leaf extract on hatchability and post-hatch performance in Cobb 500 broilers

<title>Abstract</title> <p> Embryonic losses, poor day-old chick quality, and feed inefficiency are major constraints to poultry productivity, highlighting the need for targeted research in these areas. This study investigated the impact of <italic>in ovo</italic> injections <italic>of Ocimum gratissimum extract (OGE)</italic> on hatchability and broiler performance. A total of 600 fertile eggs were randomly assigned to six treatments: T0 ⁺ (no injection), T0 ⁻ (saline injection), TT (perforation only), and T ₂₅ , T ₅₀ , T ₇₅ injection of 0.1 mL OGE at 25, 50, or 75 µg/mL, respectively. After hatching, the treatments were evaluated for embryo mortality, hatchability, hatch duration and chick quality. Furthermore, feed intake, body weight, and feed conversion ratio were evaluated in 125 chicks per treatment during six-week trial. Treatments did not significantly affect hatching events, including internal and external pipping, or hatch duration (P &gt; 0.05). However, T ₅₀ group exhibited significantly higher hatchability and lower embryonic mortality compared to the other groups. No significant difference (p &gt; 0.05) was observed between the groups in chick quality. Newly hatched chicks in the T ₅₀ group exhibited the highest mean body weight and the lowest yolk weights. Although feed intake was similar across all treatments during the rearing period, final body weights for the T ₂₅ , T ₅₀ , and T ₇₅ groups were significantly higher than those of other treatments. Additionally, the T ₀ ⁺ , T ₂₅ , T ₅₀ , and T ₇₅ groups exhibited better feed conversion ratios. In conclusion, the <italic>in ovo</italic> administration of <italic>Ocimum gratissimum</italic> extract optimized incubation parameters and promoted enhanced growth performance in broiler chicks. </p>