Fusar Poli Sara, Freu Gustavo, Lohana Dos Santos Letícia, Piccinini Renata, Bronzo Valerio, Gioia Gloria, Moroni Paolo, Addis Maria Filippa, Veiga Dos Santos Marcos
Department of Veterinary Medicine and Animal Sciences - DIVAS, University of Milan, Lodi 26900, Italy.
Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo (USP), Pirassununga, São Paulo 13635-900, Brazil.
Vet Anim Sci. 2025 May 1;28:100459. doi: 10.1016/j.vas.2025.100459. eCollection 2025 Jun.
Bedding type and management influence bacterial growth, potentially increasing the risk of new intramammary infections (IMI) in dairy cows. We investigated the effect of various concentrations of lime-based conditioner (LBC) on four environmental udder pathogens ( and ) inoculated into new sand, recycled manure solids (RMS), and sawdust. Bedding substrates were collected from commercial dairy farms, sterilized, and separately inoculated with bacterial suspensions. Increasing concentrations of LBC (0 %, 10 %, 15 %, and 20 %) were applied and samples were incubated for 24, 72, and 168 h at 28 °C to assess growth dynamics, dry matter content (DM), and pH. LBC increased the pH of all bedding materials. In sand and RMS, pH levels rose substantially, reaching 12.83 ± 0.05 and 11.72 ± 0.12, respectively. In sawdust the pH increase was lower, reaching 10.91 ± 0.14 with 20 % LBC. Sand showed inherent resistance to bacterial growth, with 10 % LBC completely inhibiting bacterial proliferation. Untreated RMS readily supported bacterial growth and required high LBC concentrations. In RMS, LBC controlled and better than and Sawdust required LBC concentrations of 20 % to effectively control growth was generally unaffected by LBC, while growth was inhibited in sawdust even without LBC addition. LBC was therefore successful in reducing mastitis pathogen loads, with an effectiveness depending on concentration and substrate type. Future research on practical on-farm applications will be required to validate these findings.
垫料类型及管理方式会影响细菌生长，有可能增加奶牛新发乳房内感染（IMI）的风险。我们研究了不同浓度的石灰基调理剂（LBC）对接种于新沙子、回收粪便固体（RMS）和锯末中的四种环境乳房病原体（及）的影响。垫料基质取自商业奶牛场，进行灭菌处理，然后分别接种细菌悬液。施加浓度不断增加的LBC（0%、10%、15%和20%），并将样品在28℃下孵育24、72和168小时，以评估生长动态、干物质含量（DM）和pH值。LBC提高了所有垫料的pH值。在沙子和RMS中，pH值大幅上升，分别达到12.83±0.05和11.72±0.12。在锯末中，pH值升高幅度较小，20%的LBC使其达到10.91±0.14。沙子显示出对细菌生长的固有抗性，10%的LBC完全抑制了细菌增殖。未经处理的RMS很容易支持细菌生长，需要高浓度的LBC。在RMS中，LBC对和的控制效果优于和。锯末需要20%的LBC浓度才能有效控制。的生长一般不受LBC影响，而即使不添加LBC，锯末中的生长也受到抑制。因此，LBC成功降低了乳房炎病原体载量，其有效性取决于浓度和基质类型。未来需要进行关于农场实际应用的研究来验证这些发现。
