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Two bulls standing in a field Two bulls standing in a field

At River Creek, our SimAngus bulls are built to work on Angus cows. The best thing about hybrid vigor is that it’s cumulative. As you begin to crossbreed, your cowherd will be more fertile, produce more milk and have longer longevity - resulting in a 25% increase in lifetime cow productivity 1. Cundiff and Gregory, 1999


  • 89%

    Rank in Top 25% (or better) for API

  • 98%

    Had an above breed average API EPD

  • 11.2%

    Avg. Rank for API

River Creek Herd vs. Breed Average

  • All Purpose Index (API) EPD

    River Creek herd ranks in top 11.2% for API

    River Creek Herd Breed Average

Improvements in production from heterosis may be captured by having both a crossbred calf and a crossbred cow. The following two tables summarize the effects of individual heterosis (crossbred calf) and maternal heterosis (crossbred cow). These tables include results from numerous crossbreeding studies conducted in the Southeast and Midwest involving several breeds. The advantage of the crossbred calf is two-fold: an increase in calf livability coupled with an increase in growth rate. Perhaps the most important advantage for crossbreeding is realized in the crossbred cow. Maternal heterosis results in improvements in cow fertility, calf livability, calf weaning weight, and cow longevity. Collectively, these improvements result in a significant advantage in pounds of calf weaned per cow exposed, and superior lifetime production for crossbred females.


Individual Heterosis: Advantage of the Crossbred Calf 1
Trait Observed Improvement % Heterosis
Calving rate, % 3.2 4.4
Survival to weaning, % 1.4 1.9
Birth weight, lb. 1.7 2.4
Weaning weight, lb. 16.3 3.9
ADG, lb./d .08 2.6
Yearling weight, lb. 29.1 3.8
1 Adapted from Cundiff and Gregory, 1999.


Maternal Heterosis: Advantage of the Crossbred Cow 2
Trait Observed Improvement % Heterosis
Calving rate, % 3.5 3.7
Survival to weaning, % .8 1.5
Birth weight, lb. 1.6 1.8
Weaning weight, lb. 18.0 3.9
ADG, lb./d .08 2.6
Longevity, yr. 1.36 16.2
Cow Lifetime Production:
No. Calves .97 17.0
Cumulative Wean. Wt., lb. 600 25.3
2 Adapted from Cundiff and Gregory, 1999.
  • Over the past several years we have utilized River Creek Farms purebred Simmental bulls on our Angus based commercial cow herd. During that time we have seen increased weaning weights and overall animal performance as a result of the hybrid vigor provided by their genetics. This increase in profitability is coupled with unparalleled calving ease and animal disposition. We couldn't be more satisfied with their genetics and would recommend River Creek Farms to anyone.

    Keith Mitchell, Mitchell Farms Rosebud, TX
  • We have used your bulls for over 25 years. We like the calving ease and solid weaning weights the bulls have added to our herd. We have also been very pleased with the SimAngus bulls and the cross breeding traits that have improved the calves.

    Tim Woodruff Wamego, KS
  • The best part of River Creek bulls is the people behind them. They have a good guarantee and they stand behind their cattle completely. Great people to do business with and I have not even been to a sale. I spent a lot of time on the phone with Joe, and he was very helpful in getting the bulls that have been a real asset to my program.

    Ron Brown, Rimrock Ranch Wray, Colorado