Chen Hui, Liu Shixiong, Li Songjian, Li Dongfang, Li Xueqiang, Xu Zixuan, Liu Dacheng
College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China.
Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Hohhot, China.
Front Vet Sci. 2024 Jul 23;11:1424073. doi: 10.3389/fvets.2024.1424073. eCollection 2024.
As effective growth-promoters and immune-modulators, yeast fermented products have shown positive effects in ruminants. To explore the mechanisms of yeast culture promoting growth and regulating immunity, this study investigated the effects of yeast culture, and β-glucan as one of its main active ingredients, on the growth performance, immune function, antioxidant capacity and hormonal profile in Mongolian ram lambs.
One hundred and five Mongolian ram lambs were randomly assigned to 3 groups, with 35 replicates in each group. The dietary treatments were: total mixed ration (TMR) as the control group, TMR supplemented with 50-70 g/kg yeast culture (YC) or 75 mg/kg β-glucan. The test period was 137 days. All the sheep were weighed and 6 serum samples were collected in each group on days 0, 30, 60, 90 and 130, respectively.
The results showed that both YC and β-glucan could promote the growth performance with increased average daily gain and decreased feed to weight gain ratio. Moreover, these two feed additives facilitated the immune function by selectively increasing the serum levels of lysozyme, IgG, IgM, INF-γ, TNF-α and some interleukins (IL-1β, IL-2, IL-6 and IL-8); ameliorated the antioxidant capacity with higher total antioxidant capacity and enzyme activities of catalase and glutathione peroxidase; altered the metabolism-associated hormone levels with higher growth hormone and thyroid hormone T3 but lower cortisol and insulin.
In conclusion, both YC and β-glucan could improve the growth performance, immune function and antioxidant capacity, and regulate the serum levels of metabolism-associated hormones, thus exerting effects of promoting growth and improving immune function. Therefore, YC could be considered as a suitable potential alternative strategy to antibiotics and be used as an animal feed additive. This article provides a theoretical basis for the clinical application of such yeast fermented preparations in mutton sheep husbandry.
作为有效的生长促进剂和免疫调节剂，酵母发酵产品已在反刍动物中显示出积极作用。为探究酵母培养物促进生长和调节免疫的机制，本研究调查了酵母培养物及其主要活性成分之一β-葡聚糖对蒙古羔羊生长性能、免疫功能、抗氧化能力和激素水平的影响。
105只蒙古羔羊随机分为3组，每组35个重复。日粮处理为：全混合日粮（TMR）作为对照组，添加50 - 70 g/kg酵母培养物（YC）或75 mg/kgβ-葡聚糖的TMR。试验期为137天。分别在第0、30、60、90和130天对所有绵羊称重，并每组采集6份血清样本。
结果表明，YC和β-葡聚糖均可促进生长性能，提高平均日增重并降低料重比。此外，这两种饲料添加剂通过选择性提高血清溶菌酶、IgG、IgM、INF-γ、TNF-α和一些白细胞介素（IL-1β、IL-2、IL-6和IL-8）水平来促进免疫功能；通过提高总抗氧化能力以及过氧化氢酶和谷胱甘肽过氧化物酶的酶活性来改善抗氧化能力；通过提高生长激素和甲状腺激素T3水平但降低皮质醇和胰岛素水平来改变代谢相关激素水平。
总之，YC和β-葡聚糖均可改善生长性能、免疫功能和抗氧化能力，并调节代谢相关激素的血清水平，从而发挥促进生长和改善免疫功能的作用。因此，YC可被视为抗生素的合适潜在替代策略，并用作动物饲料添加剂。本文为这种酵母发酵制剂在肉羊养殖中的临床应用提供了理论依据。
