Multiple Effects of Egg Weight, in Ovo Carbohydrates, and Sex of Birds on Posthatch Performance in Broilers

Chickens raised for their meat (Gallus gallus domesticus) tend to have a critical phase of life right after hatching due to the management of modern production systems. Early nutrition strategies such as in ovo intervention can be an alternative means to support growth and gut health by compensating for the energy deficit after pipping out of the egg. In the current study, 1200 Ross 308 eggs were used to examine the effects of a complex carbohydrate solution of disaccharides and glucose applied in ovo on hatchability, the hatching time of different-sized eggs, and the development, performance, and carcass characteristics of broilers of both sexes. The eggs were divided into three treatment groups: intact (NT), in ovo saline (ioS), and in ovo carbohydrate mixture (ioCH). The incubation protocol was performed according to the recommendations of Aviagen (2019), and the in ovo process was carried out on day 17 by manually injecting 0.5 mL of the solutions into the amniotic fluid. After hatching, the birds were kept in floor pens until day 35 and fed ad libitum in a three-phase feeding program. Body weight, average daily weight gain, feed intake and conversion, and carcass characteristics were measured during the trial. In ovo carbohydrates reduced hatchability by 15%, while growth performance and the weight of thigh and breast muscle were enhanced significantly (p < 0.05) compared with ioS as a possible outcome of carbohydrate-to-muscle satellite cell proliferation and protein accumulation. However, further study is needed to refine the in ovo carbohydrate supplementation method to minimize the mortality of embryos during hatching.