Effect of synbiotics administered in ovo on microvascularization and histopathological changes in pectoral muscle and the biochemical profile of broiler chicken blood

The aim of this study was to investigate whether injecting synbiotics to the egg air chamber on d 12 of embryo incubation will affect the processes of angiogenesis, and thus the share of histopathological changes in superficial pectoral muscle, as well as Ca and P in blood of 42-day-old broiler chickens. The eggs containing viable embryos were injected with 0.2 mL suspension of 1/physiological saline, 2/SYN1 composed of galactooligosaccharide (GOS) (trade name: Bi(2)tos®, Clasado Biosciences Ltd, UK) and L. salivarius or 3/SYN2 composed of RFO and L. plantarum. All birds were fed ad libitum the standard commercial feed mixtures: starter, grower, and finisher, with a constant access to water and feed. Injecting synbiotics in ovo on d 12 of the embryonal development significantly affected the blood supply to superficial breast muscle in broiler chickens. The highest density of capillaries in the muscle area under study and per muscle fiber were identified in the group of birds the egg air chamber of which was provided with synbiotic GOS+L. salivarius. Consequently, for the muscles of the birds injected with the same synbiotic there was found the highest share of normal fibers and least necrosis and splitting, as compared with the control. The conducted research confirms the relationship between the blood supply to the muscle and the occurrence of pathological changes. We have observed a positive effect of synbiotics on the microvascularization and the size of histopathological changes in the chicken muscle, which, from a practical perspective, can affect the health status and the meat quality. Blood biochemical analyses showed that the in ovo injection of synbiotics did not significantly affect the level of parameters, except for Ca and P. A significant increase in the concentration of these minerals in the blood of chickens injected with SYN1 could have a positive effect on the angiogenesis process.