PS6-2. Dietary Flaxseed Oil Influences Intestinal Health and Growth of Broiler Chickens During Necrotic Enteritis.

Abstract Necrotic enteritis (NE) caused by Clostridium perfringens is a prevalent enteric disease in poultry, leading to significant economic losses. Flaxseed oil is rich in omega-3 polyunsaturated fatty acids, which have anti-inflammatory properties and may offer a nutritional strategy to mitigate NE pathogenesis. This study investigated the effects of dietary flaxseed oil on growth performance, intestinal lesion scores, and systemic nitric oxide (NO) concentrations in broiler chickens during experimentally induced NE. Day old broiler chicks (n = 480, Ross 708 male) were randomly allocated to four dietary treatments in a completely randomized design: PCON (3% poultry fat, unchallenged), FLAX (3% flaxseed oil, unchallenged), APCON (3% poultry fat, challenged), and AFLAX (3% flaxseed oil, challenged), with 6 replicate pens of 20 chicks each. Necrotic enteritis was induced in challenged groups by oral administration of a 10× dose of coccidia vaccine on day 14, followed by C. perfringens (2.8 × 10⁸ CFU/mL) on day 19. Growth performance parameters, Body weight (BW) and Feed Intake (FI) were recorded to calculate the Body Weight Gain (BWG) and Feed Conversion Ratio (FCR). Intestinal lesion scores were assessed on days 20 and 26, and serum NO concentrations were also measured. Data were analyzed using a one-way ANOVA with the GLM procedure (p < 0.05). BWG was significant (p < 0.05), with AFLAX having a higher BWG (0.6358 kg) compared to APCON (0.6132 kg). Although the FI was not different, FCR was significant (p < 0.05), with AFLAX (1.4100) having a lower FCR than APCON (1.4374), and FLAX (1.3201) having the lowest FCR among the treatments. Mortality did not differ significantly among treatments, but was higher in APCON (18%) than AFLAX (15%). APCON showed the highest NO concentrations and the most severe intestinal lesions, whereas AFLAX birds showed markedly reduced lesion scores across the duodenum, jejunum, and ileum. AFLAX showed significantly lower intestinal lesion scores on both day 20 (0.83 vs. 1.67) and day 26 (0.50 vs. 3.17) than APCON. On day 20, APCON had the highest NO (333.57 µM), while FLAX and PCON showed lower values (82.40 and 86.05 µM). By day 26, AFLAX (59.83 µM) showed a substantial reduction relative to APCON (87.06 µM). The reduction in intestinal lesions and systemic NO concentrations in AFLAX birds suggests that flaxseed oil exerts anti-inflammatory effects, likely mediated by omega-3 fatty acids modulating the inflammatory response to C. perfringens challenge. Dietary flaxseed oil reduced the inflammatory nitric oxide response and intestinal lesion severity associated with necrotic enteritis, while supporting favorable growth performance. These findings highlight flaxseed oil as a promising nutritional strategy for enhancing intestinal health and resilience in broiler chickens under enteric disease pressure.