Mark E. Carson BSc. (Agr). MSc., Gencor Herd Reproduction Analyst When analyzing a herd's reproductive performance, it's important to know what heat detection tools are being used to select cows for breeding and then also the subsequent performance of these tools. Take an example of a herd using a combination of observed heats, electronic activity monitoring and Ovsynch to breed their cows. For this particular herd, the breedings must be categorized as one of the following: Observed heats Activity monitored First service synch Re-synch My preference is to categorize first service synch from re-synch cows (timed A.I. used on second breeding or above). This allows me to gain additional insight into the performance of timed A.I. protocol. Categorizing breedings provides you with two key pieces of information about your herd: The number of cows being submitted by each tool What the conception rate is for each method Having this information helps you make better reproductive decisions by knowing both what tools are working and also what tools need improvement. For Dairy Comp 305 and Scout users, activating the Breeding Code feature will help categorize and track breeding the performance of each breeding tool. If you're not tracking how your cows are being submitted for breeding, work with your herd veterinarian or Semex representative to help set up a system to collect this valuable information.