Impact of Dietary Iraqi Concentrated Protein on the Growth Performance and Health Status of E. coli Challenged Broiler Chickens.

This study evaluated the impact of Iraqi Concentrated Protein (ICP) supplementation on the growth performance, jejunal morphology, and serum biochemical parameters of broiler chickens exposed to an Escherichia coli challenge. A total of 600 day-old Ross 308 chicks were randomly allocated to 60 pens in a 2×5 factorial design. The two main factors were the presence or absence of E. coli challenge and five dietary treatments: a control diet, antibiotics, and three levels of ICP (0.75%, 1.5%, and 3%). The E. coli challenge had a marked negative impact on performance indicators. By day 10, challenged birds exhibited significantly lower feed intake (FI) and weight gain (WG), along with higher mortality, compared to unchallenged birds. On days 24 and 35, the challenged group had reduced WG, elevated mortality rates, and poorer feed conversion ratios (FCR). Dietary inclusion of ICP significantly enhanced WG and FCR compared to the control group. Challenged birds increased serum levels of albumin, ALT, AST, total protein, uric acid, and globulin (P<0.001). However, birds receiving the control diet had higher ALT, AST, and uric acid levels than those supplemented with ICP. Additionally, the E. coli challenge decreased villus height and increased muscle thickness. In contrast, birds supplemented with ICP displayed improvements in villus height, villus-to-crypt ratio, and villous surface area, while the deepest crypts were observed in birds receiving antibiotics. In summary, ICP supplementation demonstrated a protective effect against E. coli infection by enhancing growth performance and intestinal health in broiler chickens.