PSIII-26 Effect of dietary fat sources on blood metabolites of broiler chickens challenged with Salmonella.

Abstract Blood gases, electrolytes, and hematology values in broilers are critical indicators of metabolic status, stress, and overall health. However, limited studies have examined changes in blood parameters in response to nutritional interventions. This study aimed to investigate blood metabolite changes in Salmonella-challenged broiler chickens fed different dietary fat sources. A total of 1,152 one-day-old, non-vaccinated male Ross 708 chicks were randomly allocated into four dietary treatments across 48 pens. Birds received a basal diet from day 0 to day 3, followed by treatment diets differing in fat sources: Soy Oil (T1), Poultry Fat (T2), Acidulated Fat (T3), and Palm Oil (T4). On day 7, all birds were orally challenged with 1 mL, 10⁸ CFU of a nalidixic acid-resistant Salmonella Enteritidis and Salmonella Typhimurium cocktail. Blood samples were collected from six birds per treatment group from the jugular vein after electrical euthanasia on days 35 and 42 (N = 48). Hematology, blood gas, and electrolyte parameters were analyzed using i-STAT CG8+ cartridges. Statistical analysis was conducted using Proc GLM in SAS, with significance at P ≤ 0.05, and mean separation performed using the HSD test. At week 5, no significant differences were observed among treatment groups for glucose, hemoglobin (Hb), hematocrit (HCT), base excess (BE), partial pressure of oxygen (pO₂), partial pressure of carbon dioxide (pCO₂), total carbon dioxide (TCO₂), bicarbonate (HCO₃⁻), or oxygen saturation (SO₂). However, a significantly higher pH level and a lower concentration of potassium (K⁺) ions were detected in T1 compared to T4 (P ≤ 0.05). The pH values of 7.51, 7.48, 7.47, and 7.41 and the potassium concentrations of 5.38, 5.66, 6.06, and 6.54 were observed in T1, T2, T3, and T4, respectively. At week 6, a significantly lower glucose value of 187.59 mg/dL was detected in the T2 group compared to an average glucose value of 237.67 mg/dL in T3 (P ≤ 0.05). Additionally, Hb and HCT values were significantly lower in T2 compared to T1 (7.3 g/dL) and T4 (7.0 g/dL) (P ≤ 0.05). The HCT value in T2 was 17.4%, while higher values of 21.5% and 20.8% were observed in T4 and T1, respectively. No significant differences were found in blood gases (pO₂, pCO₂, SO₂, TCO₂, BE, HCO₃⁻) or electrolyte metabolites (K⁺, ionized calcium [iCa], sodium [Na⁺]) among treatments. Lower glucose and hematocrit values observed in birds fed the poultry fat diet (T2) could potentially be associated with suppressed immunity in broilers, however, further studies are required to correlate production performance with blood parameter changes to better understand the metabolic impacts of different fat sources.