Use of a stochastic simulation model to assess effects of diagnostic specificity of systems for detecting ovulating cows on herd reproductive performance in year-round calving dairy herds

Evaluation of a cow‐side milk progesterone assay and assessment of the positive predictive value of oestrus diagnosis by dairy farmers in New South Wales

“…In cows that have already been previously bred, the ability to diagnose CL‐positive cows (which may be pregnant) will help farmers to avoid inseminating cows that may already be pregnant, particularly in herds with a low PPV of oestrus diagnosis. Previous studies have estimated that 13% of re‐inseminated pregnant cows will lose the fetus, although the extent of losses vary with the number of days since insemination. Weaver et al found that cows inseminated to oestrus and then re‐inseminated into the uterine body 12–24 days later had a pregnancy rate of 4% versus 40.6% for controls .…”