The adverse influences of elevated ambient temperatures during the summer season on the rabbit industry have received increased global attention. Prodigiosin (PRG) is a natural pigment with powerful antioxidant activities. In this study, the aim was to explore the potential action of PRG for mitigating the negative impacts of heat stress in growing rabbits. A 120 growing rabbits (weaned, males, 35 days of age) were randomly allocated into four treatments of 30 rabbits each. The first group was received a basal diet without PRG (0 g/kg diet), and the 2, 3, and 4 groups received diets including PRG (50, 100, 150 mg/kg diet, respectively) for eight consecutive weeks during the summer season. Results showed that PRG improved significantly final body weight (FBW), daily body weight gain (DBWG), and feed conversion ratio (FCR), but did not affect feed intake (FI). Compared with the control, PRG addition with 50, 100, and 150 mg/kg diet decreased significantly total bilirubin (TB), triglycerides (TG), gamma-glutamyl transferase (GGT) and creatinine levels. The plasma levels of total antioxidant capacity (TAC) and glutathione in the group received (100mg/kg) diet were significantly higher than those in the other groups. Still, MDA was markedly reduced in PRG-treated groups compared with the control. Pro-inflammatory cytokines levels (interleukin-4 (IL-4) and Interferon gamma (IFNγ) were significantly decreased (P<0.001), but lysosome activity and nitric oxide levels were significantly increased (P<0.009) in rabbits fed diets containing PRG (100 and 150 mg/kg) compared with those in the control group. Pathological screening of liver tissues shown moderate to severe degenerative and necrotic alterations in rabbits exposed to thermal stress, which is enhanced with supplementation of PRG at different levels. The obtained results suggest that PRG as a novel feed additive could be effectively used to improve the growth and health status through enhancing immunity, and antioxidant features further reduce the inflammation cytokines of growing rabbits exposed to heat stress conditions.

夏季环境温度升高对兔子产业的不利影响已引起全球关注。Prodigiosin（PRG）是具有强大抗氧化活性的天然色素。在这项研究中，目的是探索PRG减轻生长中的兔子热应激的负面影响的潜在作用。将120只生长中的兔子（断奶，雄性，35天大）随机分配到每只30只兔子的四种处理中。第一组接受无PRG的基础饮食（0 g / kg饮食），第2、3和4组在饮食期间连续八周接受包括PRG的饮食（分别为50、100、150 mg / kg饮食）。夏季。结果显示PRG显着改善了最终体重（FBW），每日体重增加（DBWG）和饲料转化率（FCR），但不影响采食量（FI）。与对照组相比，添加50、100和150 mg / kg饮食的PRG可以显着降低总胆红素（TB），甘油三酸酯（TG），γ-谷氨酰转移酶（GGT）和肌酐水平。饮食（100mg / kg）组的血浆总抗氧化剂能力（TAC）和谷胱甘肽水平显着高于其他组。尽管如此，与对照组相比，PRG治疗组的MDA明显降低。饲喂含PRG的家兔的促炎细胞因子水平（白介素4（IL-4）和干扰素γ（IFNγ）显着降低（P <0.001），但溶酶体活性和一氧化氮水平显着升高（P <0.009） （100和150 mg / kg）与对照组相比。肝脏组织的病理学筛查显示，在遭受热应激的兔子中，变性和坏死性变化为中度至重度变化，不同水平的PRG补充可增强这种变化。获得的结果表明，PRG作为一种新型饲料添加剂可通过增强免疫力而有效地用于改善生长和健康状况，而抗氧化剂特性可进一步减少暴露于热应激条件下的成年兔子的炎症细胞因子。