[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，以乳房炎症反应为特征。经济与环境影响以及抗菌药物残留问题，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）是一种免疫调节剂，对包括乳腺炎在内的传染性疾病具有潜在预防作用。本研究旨在评估口服β-葡聚糖对泌乳奶牛的作用效果。本研究选用20头泌乳奶牛，随机分为对照组与处理组，每组各10头。处理组每日饲喂5g来源于酿酒酵母（Saccharomyces cerevisiae）细胞壁的1,3-1,6 β-葡聚糖，该制剂稀释于谷物饲料中，连续饲喂60天；对照组仅饲喂基础日粮。试验期间，采用加州乳腺炎测试（California Mastitis Test, CMT）、体细胞计数（Somatic Cells Counting, SCC）检测亚临床乳腺炎情况，并记录日产奶量，同时检测乳脂与乳蛋白含量。结果显示，两组在CMT与SCC检测出的亚临床乳腺炎发生率、产奶量以及乳蛋白、乳脂组成方面均无统计学显著差异。因此，本研究未观察到口服纯化β-葡聚糖对奶牛乳腺炎的防治效果。该结果归因于受试制剂在瘤胃内发生降解。据此，建议后续研究采用其他给药途径，并对分离得到的β-葡聚糖采用瘤胃保护技术，以评估酿酒酵母来源的1,3-1,6 β-葡聚糖的应用效果。