Exploring critical animal-based traits as potential predictors of production diseases in dairy cattle: a systematic review and meta-analysis

This meta-analysis comprehensively evaluates the impact of production diseases on dairy cattle, examining a variety of physiological, metabolic, and behavioral traits. From an initial set of 3 349 records, a rigorous selection process resulted in 56 relevant articles, highlighting the strict criteria employed. The low inclusion rate of 1.67% underscores the dedication to studying quality and significance. Common reasons for exclusion, such as statistical methodology and the lack of a negative control group, emphasize the necessity for robust scientific investigation. The study reveals key indicators of production diseases, such as decreased milk production, weight loss, a low body condition score, digestive disorders, lameness, and respiratory distress. These findings align with existing knowledge, emphasizing the multifaceted nature of production diseases and their broad impact on dairy cattle health. Diseased animals consistently exhibit higher parameter values, supported by confidence intervals that indicate result precision. Subgroup analyses offer nuanced insights into the specific effects of diseases and interventions on different characteristics. Metritis and Mastitis significantly affect milk production, highlighting the economic implications for dairy farmers. Interventions such as improved milking techniques show promise. Similarly, interventions involving veterinary medications and controlled energy diets effectively mitigate weight loss, a low body condition score, and digestive disorders. The analysis underscores the vulnerability of dairy cattle to reproductive issues, metabolic imbalances, and increased susceptibility to infections. Interventions addressing these challenges include hormone therapy, balanced diets, and vaccination programs. Behavioral changes and feeding habits emerge as significant indicators of dairy cattle well-being. Ovarian cysts are identified as a major contributor to behavioral changes, necessitating targeted interventions. In conclusion, this meta-analysis provides valuable contributions to the field of dairy cattle health, offering specific insights into the effects of diseases and the effectiveness of interventions. These findings inform evidence-based practices for dairy stakeholders, ultimately enhancing animal welfare and promoting sustainable dairy production. However, establishing precise reference values presents challenges, warranting further investigation.