Effects of In Ovo Injection of Butyrate Glyceride Blend on Broiler Chicks’ Performance

In ovo supplementation of bioactive substances represents an effective nutritional intervention for enhancing broiler development from the embryonic stage through market age. This study investigates the impact of injecting graded levels of in ovo BGB on the physiological and developmental trajectories of broiler chicks. The investigation spans from embryonic development to a 35-day post-hatch period, assessing hatchability characteristics, chick quality, physiological indices, and growth performance. Based on the results, BGB improved chick quality at hatch by increasing body weight (p = 0.0484), Pasgar score (p = 0.0296), and several blood biochemical indicators, such as serum protein (p = 0.0005) and thyroid hormone concentrations (T3, p = 0.0001), while reducing blood glucose levels (p = 0.0180). Most notably, BGB promoted substantial improvements in intestinal morphology, including greater villus height (p = 0.0001), villus surface area (p = 0.0001), and villus-to-crypt ratio (p = 0.0020), indicating enhanced digestive and absorptive capacity. These physiological and intestinal benefits translated into superior post-hatch growth performance, characterized by higher body weight gain (p = 0.0001) and improved feed conversion efficiency (p = 0.0001). Notably, dressing percentage was significantly affected by a quadratic response (p = 0.0448), where the 0.30% BGB concentration yielded the highest dressing yield (81.1%). Furthermore, humoral immunity was strongly enhanced; immunoglobulin G (IgG) levels demonstrated a highly significant quadratic response (p = 0.0004), maximizing at 11.23 mg/mL in the 0.30% BGB group. Overall, the findings demonstrate that in ovo BGB administration, particularly at the 0.30% level, acts as a powerful developmental programming strategy that supports intestinal maturation, metabolic function, immune response, carcass traits, and long-term growth performance in broiler chickens.