The Right Bulls Produce the Right Calves

What is important is to look at the numbers and find a bull that will work within your herd, writes Kris Ringwall, Beef Specialist at North Dakota State University.
calendar icon 18 June 2009
clock icon 4 minute read

The discussion when to breed cows has to end eventually. Spring and breeding time is here at the Dickinson Research Extension Center.

The heifers were synchronized for timed insemination through an initial injection of a gonadotropin-releasing hormone (often referred to as GnRH and available in several commercial formulations) followed by seven days of progesterone administered by a controlled internal drug-release device (often referred to as CIDR, a registered trademark of DEC International, NZ, Ltd.)

Bull EPD Values
NDSU Dickinson Research Extension Center
  Last year's Angus Bull This year's Angus Bull
Calving Ease 9 14 14
Birth Weight 1.9 -.07 -1.3
Weaning Weight 53 42 58
Yearling Weight 100 84 103
Rib Eye Area .78 .09 .44

On day seven, the CIDR was removed and the heifers received an injection of prostaglandin. Fifty-four hours later (plus or minus two hours), the heifers were bred by artificial insemination (AI), given a second injection of GnRH and hauled to grass. Cleanup bulls were turned out once the heifers quit exhibiting estrus.

Two key dates loom ahead. The first will be late July when the heifers are ultra-sounded to determine the pregnancy percentage from AI. The second will be when the heifers calve.

We are hoping to avoid the trouble of this spring. Those who read BeefTalk recall we pulled more calves than expected and we even had one calf delivered cesarean.

This was unacceptable, particularly with the long, difficult winter. Many have asked who the bull was, but that is not important.

That same bull may very well work in someone else's herd. The particular breed or genetic makeup of the heifers or cows also can influence the outcome.

What is important is to look at the numbers and find a bull that will work within your herd. Last year, the center bull had a calving ease expected progeny difference (EPD) of 9, a birth weight (BW) EPD of 1.9, weaning weight (WW) EPD of 53 and yearling weight (YW) EPD of 100.

The bull ranked as an Angus trait leader for growth. He also had a rib eye area (REA) EPD of .78, which ranked the bull in the upper 1 percent of the breed. The other carcass traits also were very excellent, but enough numbers.

So what is happening as the weather warms up? This year’s surviving calves look great. “Trend setters” and “haven’t seen calves quite that good for a while” are some of the descriptions. Memories are short and those dead winter calves are buried and gone. The dry cows were converted to cash and life goes on.

What bulls did we use this year? I am not going to name them, but let's look at the data.

The center had a bull in the semen tank with a calving ease EPD of 14, BW EPD of minus 0.7, WW EPD of 42, YW EPD of 84 and REA EPD of .09.

The bull is not the growth bull that we used last year, but is certainly acceptable. The bull will be used along with another bull who also has a calving ease EPD of 14, BW EPD of minus 1.3, WW EPD of 58, YW EPD of 103 and REA EPD of .44.

The second bull is an obvious trait leader for growth and carcass in the Angus breed. We will look forward anxiously to a good artificial insemination conception rate and a great calving season.

The center knows well what happened last year. We hope that good data and good planning with the bull selection will work out beginning March 7. That’s the day the heifers are due to start calving.

We will be in the thick of calving as March arrives, but as usual, the heifers always are close to home, so we are thinking positively. On second thought, a little luck would not hurt.

Life does not always go our way and even numbers vary in accuracy. However, what else do we have? If we become fearful of muscle growth in the cattle business, we have created a very big hurdle.

June 2009

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