A. Good pregnancy rates (PR) are dependent on the rate of conception and the heat detection rate. Conception rate (CR) is the proportion of cows that are inseminated and become pregnant (US dairy herd average is 40%). And the heat detection rate (HDR) is the rate of heat detection in a 21 day period (national average is about 40%). The national average herd PR is approximately 16% (0.40 CR X 0.40 HDR=0.16 PR). So by improving detection of heat, a producer will improve their pregnancy rate.
Many farms are using heat synchronization programs to regulate estrus in their cattle. These programs work well but are dependent on staff that will give the proper injection at the right time. Failures of heat synchronization program typically are due to poor client compliance. In addition to heat synchronization programs, others depend on visual observation by employees for heat detection. Again problems will occur if employees are busy doing other tasks while doing heat detection or if the observer is unfamiliar with the signs of a cow coming into heat, in standing heat, and going out of heat. Conventionally, the timing of insemination should be based on the onset of standing estrus, i.e., inseminated about 12 hours after onset of estrus.
There are several brands of electronic heat detection systems available that are used to automatically monitor the movement of cattle. Most systems involve the use of a cow tag, receiver (that collects data from the tags on the cow) and a computer program on a farm laptop. ANIMART is now introducing the Legend Dairy Management, a complete system for continuously monitoring the activity of cows and heifers. This dynamic program provides advanced, high resolution heat detection with a system that continuously sends signals (every six minutes) to the receivers in the pens and is constantly updating information on the farm computer. Also the Legend system (exclusively available at ANIMART) offers tags that can be placed on the cow’s leg and, the best part, requires no maintenance. Beyond use for heat detection, users have used these systems to locate sick cows and cows due to freshen.