In-ovo injection of Nigella Sativa nanoparticles improves hatchability, growth performance, intestinal microbial enumeration, immunity, and gene expression of ostrich chicks

In-ovo supplements are commonly used to improve embryonic and chick development performance. This study aimed to evaluate the effect of different Nigella Sativa nanoparticle (NS-Nano) levels in ovo on hatchability and ostrich chick performance. Four hundred and fifty fertilized ostrich eggs were randomly distributed into six experimental groups: NCN, un-injection eggs, ISS, ovo injected with 0.7 % saline solution, and four levels of Nigella Sativa nanoparticles (10, 25, 50, and 75 μg/egg), respectively, on day 37 into the amniotic fluid at embryonic. After injection, standard hatching conditions were followed and hatchability and chick quality measurements were taken. After hatching, twenty-five chicks from each group were weighed, randomly distributed into five replicates, and raised for 8 weeks. The results showed that supplementing with 50 and 75 μg NS-Nano enhanced hatchability and chick quality compared to other injected groups. However, the chick weight did not differ between experimental groups. Additionally, the growth performance improved in ostriches received 50 μg NS-Nano, as the body weight increased and the feed conversion ratio decreased (P<0.05) compared to the other groups. Furthermore, plasma levels of superoxide oxidase (SOD), immunoglobulin A (IgA), and IL-10 increased, and malondialdehyde (MDA) levels decreased in ostrich chicks receiving 50 and 75 μg NS-Nano (P<0.05) than those in the other groups. Adding 50 μg NS-Nano enhanced the intestinal integrity of ostrich chicks by increasing Lactobacillus count and reducing pathogenic bacteria (P<0.05), in addition to up-regulation of MUC2 and IGF-1 genes. In conclusion, this study indicated that up to 50 μg of NS-Nano supplementation significantly promoted hatchability, chick quality, immunity, antioxidant capacity, intestinal integrity, and growth performance of ostrich chicks.