Effect of in-ovo spray application of propolis on embryonic development, hatchability, chick quality, and post-hatch performance in broiler chickens

This study investigated the effect of spraying hatching eggs with propolis on embryonic development, hatching, chick quality, growth, carcass, and organ traits at 10 d of age in broiler chickens. The experimental groups consisted of N-S (non-sprayed eggs), S-W (eggs sprayed with distilled water), and S-P (eggs sprayed with propolis). The results showed that egg weight at embryonic days (ED) 7, 14, and 18 were similar among the groups ( P > 0.05 ). The egg weight loss at ED 0–7 and 0–14 was lower in N-S compared to the other treatments ( P < 0.05 ). The yolk weight and yolk yield were lowest in N-S and highest in S-W at ED 14 ( P < 0.05) ; however, the yolk-free body mass weight was highest in N-S and lowest in S-P ( P < 0.05 ) at ED 18. In addition, at ED 18, the embryo width was highest in N-S and lowest in S-W (P < 0.05 ). The chick length at hatch was highest in S-W, and the appearance score was better in S-W and S-P chicks ( P < 0.05 ). The body weight and feed conversion ratio at 7 d of age were better in S-P chicks ( P < 0.05 ). The intestinal yield, breast, slaughter, liver, and thigh weight were lowest in S-W chicks ( P < 0.05 ). It was concluded that spraying hatching eggs with propolis may improve early post-hatch growth performance, and carcass traits without any negative effect on hatching traits.