In order to accurately and effectively perform pregnancy examinations on a large number of cows, if ultrasound is used to diagnose pregnancy in cows, the examination should be conducted 36 days after the last reproduction. If ultrasound is used to palpate the rectum of cows, the pregnancy examination should be conducted 30 days after the cows are raised.

For example, cattle herds that give birth in mid to late January will have a date for bull slaughter or artificial insemination around April 15th. If the producer is using a 45 day breeding season, the group will be prepared for ultrasound examination around June 29th and rectal palpation on July 9th.

Carl Dahlen, a beef cattle expert at the Department of Extension Services at North Dakota State University, said, "Producers can save a lot of money by identifying and eliminating non pregnant females before winter feeding

The historic bull market reached a low point in November, coinciding with the time when most producers weaned their calves and pregnant cows. According to the average market price of pure cattle from 2005 to 2010, the price difference between August or November sales is approximately $8 per hundredfold, which is equivalent to a price difference of $108 for selling 1350 pounds of cows.

However, not all producers have a breeding season, and facilities and labor undergo pregnancy checks in late summer. Dahlen believes that herds with clear breeding seasons are best suited for early pregnancy testing.

If on the same day as the pregnancy check, the bull runs continuously with the herd or is pulled out of the pasture, the producer will not be able to determine the true pregnancy status of the cow. In these cases, it is easy to identify cows that became pregnant early in the breeding season, while in reality, "open" cows may have only recently been bred. These newly bred cows may be pregnant in the early stages, and the time is too short to be observed through rectal palpation or ultrasound.

However, a small percentage of cows that are confirmed to be pregnant during early pregnancy checks will naturally miscarry before calving (most miscarriages occur 60 days after reproduction). Regardless of whether the producer chooses to undergo early pregnancy testing, fetal miscarriage will occur.

How to avoid fetal miscarriage:

1. In herds with scarce cattle, limited pastures, or limited forage, early removal of empty or pregnant cows may provide more feed resources for the remaining pregnant cows;

2. Reduce the labor of cows and avoid them working in high temperatures;

3. Use a cow ultrasound machine to detect the pregnancy status of cows and monitor real-time updates;