Effect of dietary Chlorella vulgaris and carbohydrate-active enzymes on the general health, immune status, antioxidant capacity, and liver lipids and metabolites of weaned piglets

It was evaluated the impact of dietary inclusion of <em>Chlorella vulgaris </em>(CH) and carbohydrases on the general health, immune and oxidative status, and hepatic lipids and metabolites of piglets. Forty-four male weaned piglets were allocated into four diets: control (<em>n</em>=11), CH (control diet with 5% CH, <em>n</em>=10), CH+R (control diet with 5% CH plus 0.005% Rovabio^®Excel AP, <em>n</em>=10), and CH+M (control diet with 5% CH plus 0.01% of a pre-selected four-CAZyme mixture, <em>n</em>=11) for 15 days. Total cholesterol, LDL-cholesterol and VLDL-cholesterol were increased by CH. In piglets fed CH<em>-</em>based diets, the interplay observed between IgG increase and IgM decrease contributed for piglets’ survival during weaning. <em>n</em>-6 PUFA were lower in piglets fed CH with or without feed enzymes and the inverse occurred for <em>n</em>-3 PUFA, thus benefiting <em>n</em>-6/<em>n</em>-3 ratio in the liver. The discriminant analysis applied to hepatic variables revealed a good separation between control and CH-based diets but failed to discriminate feed enzymes addition. Minor variations were promoted by Rovabio or the pre-selected enzymatic mixture, thus suggesting some improvement on microalga nutrients digestibility. Taken together, our findings indicate a health promoting effect of CH as feed ingredient in piglets’ nutrition during the weaning period, without negatively impacting on animals’ performance.本研究评估了日粮添加普通小球藻（*Chlorella vulgaris*，简称CH）与碳水化合物酶（CAZyme）对断奶仔猪的整体健康、免疫与氧化状态，以及肝脏脂质与代谢物的影响。将44头雄性断奶仔猪随机分为4组日粮处理：对照组（n=11）、CH组（基础日粮添加5% CH，n=10）、CH+R组（基础日粮添加5% CH与0.005% Rovabio® Excel AP，n=10）、CH+M组（基础日粮添加5% CH与0.01%预筛选的4种碳水化合物酶混合物，n=11），试验周期为15天。CH可提升血清总胆固醇、低密度脂蛋白胆固醇（LDL-cholesterol）与极低密度脂蛋白胆固醇（VLDL-cholesterol）水平。在饲喂CH基础日粮的仔猪中，IgG水平升高与IgM水平降低之间的协同作用，有助于仔猪断奶期的存活。饲喂含或不含饲用酶的CH日粮的仔猪，其肝脏n-6多不饱和脂肪酸（PUFA）水平降低，而n-3多不饱和脂肪酸（PUFA）水平则呈相反变化，因此优化了肝脏内n-6/n-3多不饱和脂肪酸比值。对肝脏相关变量进行判别分析的结果显示，对照组与CH基础日粮组可实现良好区分，但无法区分是否添加饲用酶的组别。Rovabio或预筛选的酶混合物仅带来轻微的代谢变化，这提示其可一定程度提升微藻营养物质的消化率。综合来看，本研究结果表明，将CH作为饲用原料添加至仔猪断奶期日粮中，可发挥健康促进作用，且不会对仔猪生产性能产生负面影响。