The Beef Cattle Institute’s Dr. Bob Larson brings you a series of “cases” employing the use of the Pregnancy Analytics mobile app. Each case will explore a unique herd and examine its reproductive efficiency, strengths, challenges and areas of improvement. The reports (linked below) will lead you through using the Pregnancy Analytics app to utilize the data and practice using it on an actual problem herd.

The case: Efficient, but there’s room for improvement in first-calf heifers

The first report examines data from a herd of 274 commercial cows palpated on Sept. 4. The herd was turned out onto one pasture with 9 bulls on May 20. One hundred eighteen of the cows were predominantly Angus, 69 were black white-faced Hereford and Angus cross, and 87 cows were a mix of mostly Angus breeds and composites.

At pregnancy checking, 92.7% of the cows were pregnant, with only 20 cows open. The majority of cows were in moderate body condition score (BCS). The goal of this herd (and for most herds) was for 60% of the cows to become pregnant in the first 21 days of breeding. It succeeded, with 62.6%. That’s considered a win, and the herd is considered to have very good reproductive overall efficiency. However, the Pregnancy Analytics app can divide the herd into valuable sub-groups, including age, revealing that the herd’s first-calf heifers did not breed up as well in the first 21 days (31%) as in the second 21 days (46.6%).

2_Pregnancy distribution_by age

Another point illustrated by graphs automatically generated by the app is that cow breed-up in the third 21 days was lower, which may indicate a problem late in the breeding season.

1_Pregnancy distribution_whole herd

Click to download and view the full report.

Dr. Larson’s follow-up questions:

Are heifers in this herd bred to calve ahead of the mature cows? Do you have calving dates for the heifers?
I encourage producers to breed heifers to calve ahead of the cows so that they have additional time to resume fertile cycles between calving and the start of the next breeding season. Some herds are able to breed heifers to calve at the same time as the cows and not experience a drop in pregnancy success for young cows getting bred for their second pregnancy (1st calf heifers) compared to the mature cows – but if this age group has poorer breed-up than the mature cows during the first 21 days of the breeding season, then I think a strong suggestion to move heifer breeding earlier is justified.

Starting about the end of June or the first of July (this would coincide with the end of the 2nd 21-day period), did any of the bulls have any problems? If not, what were pasture conditions and cow health like starting in late June?
Act on the information you receive from these questions.