Effects of in ovo injection of microalgae on hatchability, antioxidant and immunity-related genes expression, and post-hatch performance in broilers and Japanese quails

Abstract

The effects of in ovo injection of Arthrospira (Spirulina) Platensis on hatchability, antioxidant and immunity-related genes expression, and hatchling performance of broilers and Japanese quails was assessed in 2 separate experiments. In experiment 1, a total of 240 fertilised quail eggs were divided into six groups: control (without injection), sham control (0.02 CC distilled water/egg), 0.75 mg Spirulina Platensis (SP)/egg, 1.5 mg SP/egg, 2.5 mg SP/egg, 3.5 mg SP/egg. In experiment 2, a total of 192 fertilised broiler breeder were divided into four groups: control, sham control (0.2 CC distilled water/egg), 25 mg SP/egg, 35 mg SP/egg. In experiment 1, in ovo injection of SP (1.5–3.5 mg/egg) increased hatchability of chicks (p < .01). In the groups received 2.5 and 3.5 mg SP/egg the expression of HSP70 and GPx genes was lower and higher than control groups, respectively (p < .001). The expression of interferon-gamma (IFN-γ) in the chicks consumed 1.5–3.5 mg SP/egg was higher than control groups (p < .001). The groups received 1.5–3.5 mg SP had lower feed conversion ratio (FCR, p < .05). Catalase activity in hatchlings consumed 2.5 or 3.5 mg SP was the highest (p < .05). In experiment 2, in ovo injection of 25 or 35 mg SP caused the lowest HSP70 in chicks (p < .0001). During the whole period of rearing, feed intake (FI) and FCR of the broilers in ovo fed with 35 mg SP was higher than control groups (p < .01). SP can be considered as an organic supplement in hatcheries for improving hatchability and anti-oxidant status of quail and broiler hatchlings. Highlights Spirulina platensis have the potential to be considered as a functional organic supplement in commercial hatcheries. In ovo injection of Spirulina platensis can improve hatchability, antioxidant, and immunity-related gene expression in quail chicks. In ovo injection of Spirulina platensis has positive effect on heat tolerance of broiler embryo during last days of incubation.