Ospina P A, Rota N, Locatelli C, Colombo L, Pollera C, Giacinti G, Bronzo V, Casula A, Arpinelli A, Brossette V, Facchi M, Patelli A, Ruggeri A, Barberio A, Potenza G, Nydam D V, Moroni P
Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, Italy.
Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, via Celoria 10, 20133 Milan, Italy.
J Dairy Sci. 2016 Aug;99(8):6519-6531. doi: 10.3168/jds.2015-10807. Epub 2016 Jun 2.
The study objective was to compare 2 commercial dry cow mastitis products at the quarter level, with concurrent internal teat sealant application, evaluating the cure risk difference, odds of a cure, odds of a new intramammary infection (NIMI) during the dry period, and risk for a clinical mastitis (CM) case between calving and 60d in milk (DIM). A total of 590 cows (2,360 quarters) from 8 commercial dairy herds in Italy were enrolled and randomized to 1 of the 2 treatments at dry off: Cefovet A (CF; 250mg of cephazoline; Merial Italia SpA, Milan, Italy), and Cepravin (CP; 250mg of cephalonium dehydrate MSD Animal Health Srl, Segrate, Italy). Quarter milk samples were collected before dry cow therapy treatment at dry off, 2 to 9 DIM, and 10 to 17 DIM. Quarter milk samples from CM cases were collected during the first 60 DIM. Noninferiority analysis was used to evaluate the effect of treatment on the risk difference of a bacteriological cure during the dry period, the primary outcome. The odds of cure, developing a NIMI during the dry period, and the risk of a CM event within 60 DIM were evaluated with multivariable logistic regression and hazard analysis, respectively. The overall crude quarter-level prevalence of NIMI at dry off was 15.3%. The most common pathogen isolated from milk samples at dry-off was coagulase-negative staphylococci. Noninferiority analysis showed no effect of treatment on the risk difference for a cure between dry off and both postpartum samples, difference was 0.013. The least squares means from the multivariable model evaluating the odds of cure was 94% for CF and 95%for CP. We observed no effect of treatment on the odds for the presence of a NIMI at 2 to 9 DIM (least squares means: CF=0.09 and CP=0.07), nor did we note a difference in risk of experiencing a CM event between calving and 60 DIM (hazard ratio=0.8). In conclusion, no difference was observed between the 2 products evaluated when assessing the aforementioned outcomes in quarters also receiving an internal teat sealant.
本研究的目的是在乳房象限水平上比较两种市售的干奶牛乳腺炎产品，并同时应用乳头内密封剂，评估治愈风险差异、治愈几率、干奶期新的乳房内感染（NIMI）几率以及产犊至产后60天（DIM）期间临床乳腺炎（CM）病例的风险。从意大利8个商业奶牛场共纳入590头奶牛（2360个乳房象限），并在干奶时随机分为两种处理之一：头孢维特A（CF；250mg头孢唑啉；意大利梅里亚公司，米兰，意大利）和头孢拉文（CP；250mg脱水头孢洛宁；意大利默沙东动物保健公司，塞格拉特，意大利）。在干奶时进行干奶牛治疗前、产后2至9天和产后10至17天采集乳房象限乳样。在产后前60天采集CM病例的乳房象限乳样。采用非劣效性分析来评估治疗对干奶期细菌学治愈风险差异（主要结局）的影响。分别采用多变量逻辑回归和风险分析评估治愈几率、干奶期发生NIMI的几率以及产后60天内发生CM事件的风险。干奶时NIMI的总体粗乳房象限患病率为15.3%。干奶时从乳样中分离出的最常见病原体是凝固酶阴性葡萄球菌。非劣效性分析表明，治疗对干奶时与两个产后样本之间的治愈风险差异无影响，差异为0.013。评估治愈几率的多变量模型的最小二乘均值，CF为94%，CP为95%。我们观察到治疗对产后2至9天NIMI存在几率无影响（最小二乘均值：CF = 0.09，CP = 0.07），也未发现产犊至产后60天期间发生CM事件的风险有差异（风险比 = 0.8）。总之，在评估上述结局时，对于同时接受乳头内密封剂的乳房象限，所评估的两种产品之间未观察到差异。
