Resin Niero Thiago, Kappes Roberto, Scheid Angelica Leticia, Ferreira Ramos Andreina, Henrique da Silva Larissa, Cardozo Leonardo Leite, Ferraz Sandra Maria, Thaler Neto André
Centro de Ciências Agroveterinárias, Universidade do Estado de Santa Catarina (CAV/UDESC), Lages, SC, Brazil 88520-000.
Ordemilk, Treze Tílias, SC, Brazil 89650-000.
JDS Commun. 2025 Jan 10;6(3):389-393. doi: 10.3168/jdsc.2024-0696. eCollection 2025 May.
The use of double disinfectant application during premilking teat disinfection on heavily soiled teats has proven effective in reducing the teat cleanliness score and certain bacterial groups in freestall confined cows. We aimed to compare the efficacy of a single (SDA; before forestripping) and a double (DDA; before and after forestripping) disinfectant application on teat cleanliness score, bacterial counts, and the incidence of subclinical and clinical mastitis in pasture-grazed dairy cows. Initially, 2 groups of 8 cows were assigned to receive either SDA or DDA lactic acid and hydrogen peroxide application, using a dip cup. The treatments were applied at every milking to all lactating cows participating in the experiment. The experiment was conducted over an 8-mo period. Cows calving during this period were alternately assigned to one of the 2 groups after 7 d. Every 15 d, both before (PRE) and after (POST) treatment, we evaluated the teat cleanliness score (TCS) and collected swabs from teat skin to quantify gram-negative bacteria (coliform and noncoliform), spp., spp., and total bacterial count (TBC). On the same day, we also collected milk samples from individual cows to measure SCC and identify subclinical mastitis (SCC ≥200,000 cells/mL). We then classified the cows as having no subclinical mastitis and new subclinical cases based on 2 consecutive analyses. Clinical mastitis cases were recorded throughout the experiment. A variance analysis was performed to evaluate the effect of treatment on bacterial count, TCS, and SCS. After disinfection, gram-negative and spp. were the most reduced type of bacteria regardless treatment. No significant differences were observed between the DDA and SDA groups for TCS, counts of coliforms, gram-negative noncoliform bacteria, spp., spp., and TBC PRE and POST application or in reducing these variables. We transformed SCC into SCS, which was similar between groups, as well as the subclinical and clinical mastitis cases. In situations with lightly soiled teats, an extra application of disinfectant during premilking teat disinfection did not significantly improve TCS, reduce bacterial counts, SCS, or decrease the incidence of subclinical and clinical mastitis compared with a single application of disinfectant.
在对重度污染乳头进行挤奶前乳头消毒时使用双重消毒剂已被证明可有效降低散栏饲养奶牛的乳头清洁度评分和某些细菌菌群数量。我们旨在比较单次（SDA；在挤奶前）和双重（DDA；在挤奶前后）消毒剂应用对放牧奶牛乳头清洁度评分、细菌计数以及亚临床和临床乳腺炎发病率的效果。最初，将两组各8头奶牛分配为接受SDA或DDA乳酸和过氧化氢应用，使用浸杯。在每次挤奶时对所有参与实验的泌乳奶牛进行处理。实验持续8个月。在此期间产犊的奶牛在7天后交替分配到两组中的一组。每15天，在处理前（PRE）和处理后（POST），我们评估乳头清洁度评分（TCS），并从乳头皮肤采集拭子以量化革兰氏阴性菌（大肠菌群和非大肠菌群）、 菌属、 菌属以及总细菌计数（TBC）。在同一天，我们还从个体奶牛采集牛奶样本以测量体细胞计数（SCC）并识别亚临床乳腺炎（SCC≥200,000个细胞/毫升）。然后根据连续两次分析将奶牛分为无亚临床乳腺炎和新的亚临床病例。在整个实验过程中记录临床乳腺炎病例。进行方差分析以评估处理对细菌计数、TCS和体细胞评分（SCS）的影响。消毒后，无论处理方式如何，革兰氏阴性菌和 菌属是减少最多的细菌类型。在处理前后，DDA组和SDA组在TCS、大肠菌群计数、革兰氏阴性非大肠菌群细菌、 菌属、 菌属和TBC方面，或在减少这些变量方面均未观察到显著差异。我们将SCC转换为SCS，两组之间相似，亚临床和临床乳腺炎病例情况也相似。在乳头轻度污染的情况下，与单次应用消毒剂相比，在挤奶前乳头消毒期间额外应用消毒剂并未显著改善TCS、降低细菌计数、SCS或降低亚临床和临床乳腺炎的发病率。
