Effects of Selective Dry Cow Treatment on Intramammary Infection Risk after Calving, Cure Risk during the Dry Period, and Antibiotic Use at Drying-Off: A Systematic Review and Meta-Analysis of Current Literature (2000–2021)

The objectives of this paper were (i) to perform a systematic review of the literature over the last 21 yr and (ii) to evaluate the efficacy of selective dry cow treatment (SDCT) vs. blanket dry cow treatment (BDCT) in dairy cows regarding the risk of intramammary infection (IMI) after calving, new IMI risk after calving, cure risk during the dry period, and a reduction in antibiotic use at drying-off by meta-analysis. The final number of included studies was n = 3 for IMI risk after calving and n = 5 for new IMI risk after calving, cure risk during the dry period, and antibiotic use. The relative risk (RR) levels for IMI, new IMI, and cure did not differ significantly between SDCT and BDCT. This meta-analysis provides evidence that SDCT seems to be an adequate alternative to BDCT regarding udder health with a simultaneous reduction in antibiotic use. Limitations might arise because of the small number of studies included.:1. Introduction 2. Material and Methods 2.1 Search Strategy 2.2 Study Selection 2.3 Data Extraction 2.4 Assessment of Bias Risk 2.5 Statistical Analysis 3. Results 3.1 Study Selection 3.2 Study Characteristics 3.3 Outcomes 3.4 Risk of Bias 3.5 Pairwise Meta-Analysis 3.6 Subgroup Meta-Analysis 4. Discussion 4.1 Risk of IMI after Calving 4.2 Risk of new IMI after Calving 4.3 Cure Risk during Dry Period 4.4 Antibiotic Use at Drying-Off 4.5 Strengths and Limitations
Ziele dieser Studie waren (i) ein systematisches Review über die Literatur der letzten 21 yr zu erstellen sowie (ii) die Effizienz von selektivem Trockenstellen (SDCT) im Vergleich zu konventionellem Trockenstellen (BDCT) bei Milchkühen anhand von Risiko an intramammären Infektionen (IMI) post partum (pp), Neuinfektionenrisiko pp, Heilungsrisiko während dem Trockenstehen und Reduktion des Antibiotikaeinsatzes zum Trockenstellen mittels einer Meta-Analyse zu untersuchen. Die finale Anzahl eingeschlossener Studien war n = 3 für das IMI-Risiko pp sowie n = 5 für Neuinfektionenrisiko pp, Heilungsrisiko während dem Trockenstehen und Antibiotikaeinsatz zum Trockenstellen. Die relativen Risiken für IMI pp, Neuinfektionen pp und Heilung während der Trockenstehperiode unterschieden sich dabei nicht signifikant zwischen SDCT und BDCT. Diese Meta-Analyse erbringt Evidenz, dass SDCT eine adäquate Alternative zu BDCT im Hinblick auf Eutergesundheit und Antibiotikareduktion ist. Limitationen entstehen durch die geringe Anzahl an eingeschlossenen Studien.:1. Introduction 2. Material and Methods 2.1 Search Strategy 2.2 Study Selection 2.3 Data Extraction 2.4 Assessment of Bias Risk 2.5 Statistical Analysis 3. Results 3.1 Study Selection 3.2 Study Characteristics 3.3 Outcomes 3.4 Risk of Bias 3.5 Pairwise Meta-Analysis 3.6 Subgroup Meta-Analysis 4. Discussion 4.1 Risk of IMI after Calving 4.2 Risk of new IMI after Calving 4.3 Cure Risk during Dry Period 4.4 Antibiotic Use at Drying-Off 4.5 Strengths and Limitations