【摘要】 试验旨在探明饲粮添加不同水平叶酸(FA)对圆环病毒-2(PCV-2)攻击下断奶仔猪增重和组织病变的影响。选用45头PCV-2阴性、初重8.44kg的健康去势、28d断奶DLY仔猪,饲喂添加不同水平FA(0、0.3、15mg/kg)的饲粮7 d后,进行PCV-2攻毒,继续饲喂相应饲粮28 d。第1、7(攻毒前)、21天和第35天采集组织样品;测定体重、腹泻指数、组织病变、血清PCV-2特异抗体、猪瘟抗体和细胞因子水平。结果表明:无PCV-2攻击,断奶应激导致仔猪免疫组织损伤,饲粮添加15 mg/kg FA可明显改善淋巴组织病变;PCV-2攻击导致免疫抑制与组织损伤,仔猪体重极显著降低(P<0.01);饲粮不添加FA仔猪免疫抑制和组织病变最严重,添加0.3 mg/kg FA缓解了免疫抑制而组织病变减轻,添加15 mg/kg FA则不利于组织修复。更多还原

【Abstract】 To detect the effects of dietary supplementation with folic acid(FA) on body weight and histopathological changes of weanling piglets with PCV-2 challenging,a 2×3 factorial(two states: PCV-2 challenge or not;three added FA levels: 0,0.3,or 15 mg/kg) randomized block design was conducted in this study.Fourty-five PCV-2 negative,8.44 ± 0.12 kg,crossbred(Duroc × Landrace × Yorkshire) castrated piglets were weaned at(28 ± 1) days of age,and fed ad libitum with three diets for 35 days,respectively.Seven piglets from each diet group were challenged with PCV-2 in the morning of d7.Blood and tissue samples were collected on d1,d7(without PCV-2 challenge),d21 & d35.The bodyweight,diarrhea incidence,histopathological change,and serum levels of cytokines were measured,respectively.Results showed that immune tissue damages were induced by intense stress during weaning in piglets without PCV-2 infection;Dietary supplementation with FA 15 mg/kg obviously restored the tissue damage.After 14 days since PCV-2 challenge,the piglets had the depressed body weight(P<0.01) with the intensified immunosuppression and tissue damage;Compared with the basal diet,the Diet supplementation with FA 0.3 mg/kg relieved partly the immunosuppression and tissue damages;but the diet supplementation with 15 mg/kg FA disadvantaged restoration of immune system in piglets.It implied that the suitable level of dietary FA might be different for piglets with different PCV-2infection status.更多还原