Wednesday, June 10, 2015

Assessing the Economic Impacts of Estrus Synchronization and Fixed-Timed AI in Beef Production

Dr. G. Cliff Lamb
University of Florida - North Florida Research & Education Center

"We know how to synchronize the cows!" Cliff Lamb stated to start his talk at the NAAB symposium at the 2015 Beef Improvement Federation Symposium.
Fixed timed AI methods make inseminating cattle much simpler.
Lamb discussed the University of Florida North Florida Research and Education Center case study. From the onset of taking leadership of the center, Lamb set certain rules that cows had to meet to stay in the herd. This is motivated by the fact that pregnancy has 4 times greater economic impact than any other production trait. Because of its importance, shouldn't fertility be a focus?
Cows must meet certain standards, e.g. keep certain rules, to stay in the center's herd.
This include:

  • Must calve by 24 months of age
  • Cow must have a calf every 365 days
  • Cow must calve without assistance
  • Cow must provide sufficient resuource for the calf to reach its genetic potential
  • Calf must be genetically capable to perform
  • Cows must maintain their body condition score for the center's conditions
  • Disposition problems leave.


At the NFREC, heifers must conceive in the first 25 days. Heifers are pregnancy checked 28 days after the end of 25 days.

Lamb listed complicated protocols, bull selection, facilities, labor, and time as primary reasons people do not to AI.

The cost of semen and the cost of AI supplies is not increasing as quickly as the costs of natural service bulls. Thus, economics is not a valid reason not to use AI.

By synchronizing and putting selection pressure on heifers to conceive earlier, calves have been born earlier and earlier in the calving season, independent of AI conception rate. This has resulted in a $169 increase in per calf prices. This has been a $50,700 increase for the center.

In an FDA trial, 5 of the 8 herds had pregnancy rates below or at 50%, and 3 of the 8 herds had much better pregnancy rates. The difference between the successful and disappointing herds was the 3 herds had been artificially inseminating consistently for the last 8 years.

In the bull bred herds, 44% of the calves are born in the first 30 days of calving season. But, 43% of the cows are less than 50 days post partum at the beginning of the breeding season. But in an AI herd, 88% of the calves are born in the first 30 days of the calving season and only 8% are less than 50 days post partum at the beginning of the breeding season. This increases reproductive success dramatically. From synchronizing cows, 8% more calves were weaned and calves were 38 lbs heavier. Just by exposing cows to synchronization, they saw a $49 increase in income. The biggest costs in reproduction are the cost of bulls and the cow-to-bull ratio.

AI Cowculator, a smartphone app, is available to evaluate the benefits of using artificial insemination.
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