Open cows can cost cattle producers in fewer calves to sell the next year. When checking cows for pregnancy, it can be disheartening when a percentage of the herd is not pregnant. Confusion over how and why this happened can plague producers, but it is important to come up with a definitive diagnosis to identify these unknowns and prevent the same problem in the future.

“Several factors can contribute to open cows,” says Joe Campbell, DVM, Boehringer Ingelheim Vetmedica Inc. professional services veterinarian. “Your first step is to decide whether this hurdle is caused by an infectious or a non-infectious problem.”

Begin the process by checking some management items. Cows must be in good enough body condition to breed and carry a calf to term. Bulls should be examined for breeding soundness prior to each season to ensure their fertility and overall health to maximize breeding success. And, while the bull may be fertile and sound, it is also important to look at the number of cows he is expected to breed, especially with young or old bulls. If there are too many cows for the number of bulls available, there could be many cows that do not get bred that season.

Then, consider the history of the herd and the biosecurity practices. Frequent herd additions, fence line contact with high risk cattle or stray cattle that enter the herd through down fences can introduce disease to the herd that would negatively impact reproduction. Were there signs in the herd such as abortions or repeat breedings late in the breeding season, which would indicate there were problems?

If a producer can rule out non-infectious causes of open cows, then it is time to look at possible infectious sources. At this point producers should work with their veterinarian to conduct diagnostic tests to determine if disease is present and the cause of the problem, suggests Campbell.

“Diseases such as trichomoniasis, bovine virus diarrhea, leptospirosis, vibrio and infectious bovine rhinotracheitis can each take a toll on productivity,” says Campbell.

A reliable pre-breeding vaccination program can help prevent each of these infectious problems, suggests Campbell.

“Taking the necessary steps to include good management practices and sound pre-breeding vaccination programs helps cattle producers reduce losses from open cows,” says Campbell.