The Enid News and Eagle, Enid, OK

March 22, 2014

Managing cowherd fertility is important

By Rick Nelson, Extended Forecast
Enid News and Eagle

ENID, Okla. — The reproductive traits important to cattlemen generally have low heritability. In other words, this means other factors, like production environment and management of the cowherd play a larger role than genetic selection.

This would suggest that ranchers should evaluate the limitations of their production environment and consider management strategies to measure, assess and cost-effectively improve reproductive efficiency.

Pregnancy detection is the most cost-effective management tool to measure reproductive success. Yet, recent survey data suggest only 18 percent of beef-cow operations in the United States evaluate the cowherd for pregnancy. This is unfortunate, since a large portion of the financial losses attributed to infertility in beef cows is attributed to maintaining open cows.

Of the methods to check for pregnancy, rectal palpation is the most common and the most cost-effective. But even the most proficient technician or veterinarian has trouble detecting early pregnancies (less than 45 days) and aging pregnancies. Accurate diagnosis typically increases as pregnancy progresses beyond 90 days.

Ultrasound is the most accurate diagnostic tool, but it’s expensive. Ultrasound is less invasive, enables the detection of pregnancy as early as 28 days, permits fetal sexing between 60 and 80 days, and does not require handling the uterus, which minimizes the loss of early pregnancies. Recently, a commercial blood test has been developed to determine pregnancy. It’s relatively inexpensive but is only a yes/no test it doesn’t define the stage of pregnancy.

Since multiple diagnostic tools exist for producers to determine the success of their breeding season, the largest decision is the first decision of deciding to begin preg-checking the cowherd. Then, you have to define realistic expectations and interpret the results.

Were the cows in good breeding condition? Was enough bull power supplied throughout the breeding season? Sometimes asking oneself these types of questions ahead of time reduces the shock of going through the results.

To improve reproductive rates, it’s important to pinpoint the cause of open females. Here is a checklist to identify areas of potential problems and management decisions:

Cow/heifer body condition score and age

• Calving.

• Beginning of the breeding season.

• During the breeding season.

Bull power

• Bull to cow ratio. How many cows did I expect the bulls to breed?

• Ages of bulls. Were expectations too high for younger bulls?

• Terrain.

• Fertility. Were bulls fertility and trich tested prior to turnout?

• Soundness.

• Social dominance management.

Pre-breeding vaccination


• Disease coverage. What diseases were cattle vaccinated against?

• Product quality.

• Label recommendations. Was a booster dose required and was the timing of the last dose prior to the beginning of breeding season?

• Parasite control.

General herd history and biosecurity

• How were new additions to the herd screened and introduced?

• Fence line contact with neighbor’s cattle?

• Wildlife and feral hog interactions?

The goal of improving fertility in any cowherd is setting females up for success by setting realistic goals and implementing a sensible management plan. Recognize reproductive losses are going to happen, even with the best management guidelines put into practice.

The bottom line is the successful manager will make the right decisions, whenever it is necessary, to improve reproductive efficiency.

Nelson is Oklahoma Cooperative Extension Service ag educator for Garfield County.