Diseases, reproductive performance, and changes in milk production associated with subclinical ketosis in dairy cows: A meta-analysis and review

摘要: Abstract Many studies have shown that subclinical ketosis (SCK) is associated with an increased risk of developing various diseases, reproductive disorders, and changes in milk production. The present work aims at producing overview between this disorder theses outcomes. A meta-analysis the literature, including 131 different models from 23 papers, or a review when literature was scarce conducted. For each outcome, odds ratio (OR), relative risk, hazard presented for moderators to reduce heterogeneity among studies. raw change production SCK estimated adjusted, taking into consideration outcomes known interact during peripartum period. results showed 2 main categories had significant effect on adjusted risk. First, adjustment made by defining as (1) β-hydroxybutyrate concentration >1.4m M , (2) nonesterified fatty acid (NEFA) >0.4m prepartum, (3) NEFA >1.0m postpartum corrected underestimated (despite low significance). This because several trials reported relevant risks using lower thresholds values. Using threshold leads disease compared high threshold. Second, correction produced polyfactorial terms overestimation many only univariable models. OR (95% confidence interval) related abomasal displacement, clinical ketosis, early culling death, metritis, placental retention, mastitis, lameness, doubling SCC cases were 3.33 (2.60–4.25), 5.38 (3.27–8.83), 1.92 (1.60–2.30), 1.75 (1.54–2.01), 1.52 (1.20–1.93), 1.61 (1.24–2.09), 2.01(1.64–2.44), 1.42 (1.26–1.60), respectively. precision level estimate depended outcome. direct mean ± standard deviation 305-d losses 251±73kg after adjusting retention. first service calving 0.67 (0.53–0.83). calving-to-first-service interval 8 d longer calving-to-conception 16 22 cows SCK. relationships indicators quantified 1 trials. highlights need conduct further associations production, parameters.