Effect of vitamin E in ovo feeding to broiler embryos on hatchability, chick quality, oxidative state, and performance.

The objective of the present study was to ascertain the effect of in ovo feeding of vitamin E (VE) on the incubation results, quality, and oxidative state of newborn chicks and on the initial performance results. The design consisted of randomized blocks with treatments at different levels of VE (0.0, 27.5, 38.5, 49.5, and 60.4 IU). On 17.5 d of embryonic development, 780 eggs underwent in ovo injection using a manual needle. VE supplementation of 60.4 IU provided the highest hatching rate (P < 0.05) and shortest hatch window (P < 0.05). Better results regarding chick physical quality were observed in groups supplemented with VE (body weight, length, newborn chick quality score) and higher chick weight/egg weight ratios (P < 0.05). VE inoculation did not have any effect on the chicks' immunological system (P > 0.05). Greater development of the small intestine (intestine weight/yolk free chick weight and higher villi in duodenum) and better feed conversion over all periods studied (1 to 7, 1 to 14, and 1 to 21 d) were observed among chicks that received in ovo VE supplementation (P < 0.05). The total protein concentrations in the liver and striated breast skeletal muscle tissue were highest in chicks that received 60.4 IU of VE (P < 0.05). The highest catalase activity was observed in the livers of newborn chicks supplemented with 60.4 IU of VE (P < 0.05). It was concluded that in ovo VE supplementation improved the chicks' oxidative state, which led to improvements in incubation results, chick quality and performance results.