[Efficiency of oral supplementation of 1.3-1.6 beta-glucan from saccharomyces cerevisiae on the control of bovine mastitis]

ABSTRACT Bovine mastitis, one of the main diseases of dairy herds, is characterized by an inflammatory process in the udder. The economic and environmental impacts, as well as the residues of antimicrobial drugs have stimulated the research of novel alternative treatments for the prevention and treatment of diseases in dairy production cows. The beta-glucan is an immunomodulator agent, with potential preventive action for infectious diseases, including mastitis. This study aimed to assess the effectiveness of orally administered beta-glucan in lactating cows. 20 lactating cows were used, distributed into two groups, one control and one treatment, with 10 cows in each group. The treatment group received 5g of 1.3-1.6 betaglucan daily for 60 days, isolated from the cell-wall of Saccharomyces cerevisiae diluted into a grain meal, whereas the animals in the control group received only the ration. The California Mastitis Test (CMT), Somatic Cells Counting (SCC), daily production and assessments of fat and protein content in milk were done. There was no statistically significant difference between the groups concerning subclinical mastitis detected by CMT, SCC, milk production and composition regarding protein and fat content. It was not observed, therefore, the effectiveness of the use of purified beta-glucan orally administered on the control or prevention of mastitis in dairy cows. The results are attributed to the ruminal degradation of the product tested. It is, therefore, suggested that more research should be conducted using the 1.3-1.6 beta-glucan purified from the cell wall of S. cerevisiae by other administration means and ruminal protection technologies for the isolated beta-glucan.摘要：牛乳腺炎（Bovine mastitis）是奶牛群的主要疾病之一，以乳房发生炎症过程为典型特征。抗菌药物残留及其引发的经济与环境影响，推动了奶牛生产中疾病防治新型替代疗法的研究。β-葡聚糖（beta-glucan）作为一种免疫调节剂，对包括乳腺炎在内的传染病具备潜在预防作用。本研究旨在评估口服给药方式下，β-葡聚糖对泌乳奶牛的防治效果。本研究选取20头泌乳奶牛，随机均分为对照组与处理组，每组各10头。处理组每日饲喂5g源自酿酒酵母（Saccharomyces cerevisiae）细胞壁的1.3-1.6型β-葡聚糖，将其稀释于谷物日粮中，连续饲喂60天；对照组仅饲喂基础日粮。后续开展了奶牛乳腺炎加州检测法（California Mastitis Test, CMT）、体细胞计数（Somatic Cells Counting, SCC）、日产奶量以及乳脂与乳蛋白含量的测定工作。结果显示，两组在经CMT检测出的亚临床乳腺炎、体细胞计数结果、产奶量以及乳蛋白与乳脂成分方面均无统计学显著性差异。因此未观察到口服纯化β-葡聚糖对奶牛乳腺炎的防治效果。研究认为该结果归因于受试产物在瘤胃内发生降解。据此建议，未来应采用其他给药途径，并针对分离得到的β-葡聚糖应用瘤胃保护技术，开展更多相关研究，以验证源自酿酒酵母（S. cerevisiae）细胞壁的1.3-1.6型β-葡聚糖的应用潜力。