Individual differences in the behavior of dairy cows can affect their productive performance. In an attempt to summarize the scientific information available, we conducted a systematic review and meta-analysis to identify the effects of dairy cows’ temperament on milk yield. We hypothesize that calmer cows would produce more milk. We found nine publications with quantitative data available to be included in a meta-analysis. Eight additional publications that addressed the topic of interest but did not present data enough to be included in the meta-analysis (i.e., evaluated the relationships between temperament and milk yield using correlations or regressions) were used to perform a qualitative synthesis. The results of our meta-analysis indicated that the reactive cows were more productive than the calm or intermediate ones, contradicting our initial hypothesis. According to the results of the qualitative synthesis, most of the publications reported a negative association between reactive temperament and milk yield, indicating that calmer cows would produce more milk. We concluded that there are divergences in the information available about the temperament and production of dairy cows. We highlight the need for greater methodological and analytical standardization to allow a broader quantitative synthesis of the temperament effects on milk yield.

Read the full article in the Journal of Animal Science.