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Showing posts from August, 2018

ARSBC 2018: EPDs and Reasonable Expectations in Commercial Crossbred Operations

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Jared Decker, PhD
University of Missouri
One point must be clear from the very beginning: EPDs work. When we select parents based on EPDs the genetic merit for that trait increases in our herd. When we select the parents using EPDs the performance of the next generation improves. EPDs Defined EPD stands for Expected Progeny Difference. These three words are loaded with meaning, thus the need to define them here. The most loaded word is Expected. Here we use Expected the way a statistician would use the word. Expected means we are making a prediction of a future value. But, in this context, Expected also means we are describing the average of a group. What is the group for which we are predicting the average? We are predicting the average performance of the Progeny or calves out of an animal. An animal’s own performance and its EPD can be quite different, because that is not the purpose of an EPD. The EPD is predicting the average performance of that animal’s calf crop. Finally, EPDs are u…

ARSBC 2018: Pregnancy Diagnosis

Ky Pohler
Texas A&M University

Pohler will discuss many different methods of pregnancy diagnosis. Producers need to find a method that works for them.

When do cows experience pregnancy loss?
95% of time fertilization occurs.
By day 28, pregnancy has dropped to 70%, a 25% loss of pregnancies. This is referred to as early embryonic loss.
By day 42, we lose 8% more pregnancies, the pregnancy rate is now around 62%. This is late embryonic loss.

Cows all cost the same to manage. If they don't have a calf or have a calf born late in the calving season, they cost us money.

Knowing pregnancy status of the herd helps make management decisions. They can help with drought management (sell open cows) and marketing decisions. Pregnancy diagnosis also helps us evaluate bull or semen fertility and breeding program success.

Pregnancy diagnosis doesn't cost a lot, but provides a great economic benefit.

What is the ideal pregnancy test?

High sensitivity (correctly identify pregnant animals)Hi…

ARSBC 2018: Predicting and promoting fertility in bulls

Joe Dalton
University of Idaho

Sperm attributes necessary for fertilitization:

Acceptable morphologyMetabolism for production of energyProgressive motilityCapacity for hyperactive motilityStabilization of plasma and acrosomal membrane lipidsAcrosomal enzymesChromatin integrity

More is not always better. 1/2 cc straws are not better than 1/4 cc straws.
How many sperm cells are needed to get a female pregnant? It depends. Different bulls have different sperm fertility.

There are compensable semen traits, such as mis-shaped sperm, that compromise sperm quality. Increasing sperm number can compensate for this.

There are incompensable semen traits, such as genetic inviablity, that compromise sperm quality. Increasing sperm number cannont compensate for these traits.

They used Angus bulls on Nelore cows to look at the effect of sperm dose. They used 10 million, 20 million, 20 million, and 40 million sperm per straw. They put each of these treatments in different colored straws. There was no f…

ARSBC 2018: Management decisions impacting reproduction and longevity in the Southwest

Adam Summers
New Mexico State University

What are some of the management things we do to help cows stay in the herd longer?

Most literature says a cow needs to produce 3 to 5 calves to be profitable. This depends on your level of supplementation and inputs.

Heifers that calve early stay in the herd longer. Cows that calve earlier produce more pounds of calf at weaning over their lifetime. Heifers that calve early produce 550 lbs more of calf over their lifetime.

Calves that were in utero during good years (above average rain) had increased birth weights and weaning weights. Calves that were in utero during bad years (below average rain) had more calves when they became cows.

Reduced body weight prior to breeding heifers did not change the rate at which those cows left the herd.

We are not using estrus synchronization and artificial insemination as much as we should. Main concerns were labor, time, and facilities.

However, we can use a PGF2 to increase the number of heifers that calve e…

ARSBC 2018: Preparing for the breeding season in a drought

Eric Scholljegerdes
New Mexico State University

The number one limiting nutrient on rangeland, whether in a drought or winter, is going to be crude protein.

We are feeding two organisms when we are feeding a beef cow. First is the rumen microbes. The second is the cow.

We see improvement in low-quality forage intake in response to crude protein supplementation. However, in a drought year this can be an issue. When grass availability is limited, we don't want to waste that resource. This is when a conservative stocking rate comes into play.

If forage crude protein is above 8%, we probably don't need to supplement protein as intake is not going to increase. If crude protein is above 8%, we may want to supplement energy instead.

Increase in protein allows the bacteria in the rumen to more completely digest the fiber in the diet.

By-pass protein provides key amino acids.

Non-structural forms of energy, e.g. starch from cereal grains causes a substitution effect. Non-structural carb…

ARSBC 2018: Considerations for utilizing reproductive technologies in Bos indicus-influenced cattle

Jordan Thomas
University of Missouri

Bos indicus cattle are different from Bos taurus cattle. They were domesticated at a different time, in a different location from a different population than Bos taurus cattle.

The big difference between Bos indicus cattle and Bos taurus is the attainment of puberty. Bos indicus cattle reach puberty later on average. Nutrition does not cause earlier puberty, but adequate nutrition is necessary to express potential for puberty. Brahman influenced animals are very sensitive to lower target weights and their ability to reach puberty.

Modern compound bows have multiple sights for different distances. Even if we use perfect form, but use the 20 yard sight to shot a target at 60 yards, we will miss the target. We often make this same mistake when trying to hit mature cow weight targets. Cull cow weights can help us better identify the mature cow weight target.

Reproductive tract scores are a helpful tool in managing Bos indicus-influenced heifers.

Bos indic…

ARSBC 2018: General considerations for implementing an artificial insemination program or other reproductive technologies

George Perry
South Dakota State University

Criteria that heifers should meet:
What has the pregnancy rate in your heifers been over the past few years?
Have your heifer received growth promoting implants?
Have your heifers reached the target weight? Typically 65%.
What are the Reproductive Tract Scores of the heifers?

Heifers have to reach 55% of their mature weight to start reaching puberty. However, how well can we know what the mature weight will be? When targeting 55% at breeding, we are really walking on the knife's edge. By targeting 65%, we are hedging for uncertainty.

Heifers with Reproductive Tract Scores that are 1 or 2 not only have lower conception rates as heifers, they also have lower conception rates at 2-year olds.

Criteria that Cows Should Meet

What was the body condition score of your cows at calving? Should be greater than 5.
What is the current body condition score of your cows?
How many days postpartum will your bows be when estrus synchronization is started?

A…

ARSBC 2018: Tools for Timeliness, Estrus Synchronization Planner & Management Minder

Sandy Johnson
Kansas State University

There are 365 days in a year. There are 283 days of gestation, plus or minus. We have 82 days to get a cow cycling and breed.

Kansas State University and Iowa Beef Center have put together 3 versions of the Estrus Synchronization Planner, Excel, mobile, and multi-group.

The sync planner is freely available at http://www.iowabeefcenter.org/estrussynch.html.

In the tool, you select the type of protocol you are using (estrus detection, estrus detection with clean up AI, and fixed-time AI).


The mobile version is available at www.estrussynch.com.

They also have a multi-group version of the Excel estrus synchronization planner. It is important to enable macros within the Excel program so the sheet can work. This allows you to have two groups of heifers, or a group of heifers and a group of cows. This allows you to print out a calendar.

The estrus planner also produces a supply list.

The estrus planner is focused on the few weeks of breeding. Johnson has …

ARSBC 2018: Control of Estrus and Ovulation in Beef Cows and Heifers

David Patterson
University of Missouri

The goals of developing FTAI protocols:

Easy to schedule and administerReduce animal handlingResult in a highly synchronized and fertile estrus and ovulation

Protocols in Heifers
Make sure you are using the protocols for the current year. Don't use protocol sheets that are several years old, as the protocols are changed and improved.

"With an MGA program, intake is key" Patterson said. He does not recommend top dressing the MGA, but mixing it into a 3 to 5 lbs carrier.

MGA has a much broader distribution of the timing of estrus expression compared to a 14-day CIDR protocol.

With a MGA protocol, you AI 72 hours after PGF2 administration. With a CIDR protocol, heifers are AI'ed 66 hours after PGF2 administration.

You should not see any estrus expression during MGA feeding periods. If you do see heifers in heat, then there is a problem with MGA intake.

Prior to the first breeding season, there needs to be heifer management.
A health p…

ARSBC 2018: Physiology of the Estrous Cycle, Application of Basic Principles

Michael Smith
University of Missouri

The estrous cycle averages 21 days, with a range of 17 to 24 days. 
There is variation in how long cows express estrus. Most cows express estrus for more than 11 hours. However, there is a significant number of cows who express estrus for less than 10 hours. These cows are often the ones that are missed in heat check programs. The success of artificial insemination programs is a function of both estrus detection and pregnancy rate.
The presence of progestorone prevents ovulations and the expression of estrus. We use this principle in estrus synchronization procotols to synchronize estrus and ovulation.
There are three catagories of horomones used in estrus synchronization: Progestins/ProgesteroneProsteglandinsGnRH
Progesterone blocks estrus, blocks ovulation, preserves oocyte quality, and prepares for pregnancy. The two progestorone products used in the US are MGA and CIDR.
MGA feeding for 14 days syncs heifers to all express estrus at the same day. …

Show-Me-Select Genomic-Enhanced EPD Requirement: Where to purchase the DNA test

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The Show-Me-Select Replacement Heifer Program recently announced the requirement that natural service sires have genomic-enhanced EPDs. Where possible, genomic-enhanced EPDs should be available on the bull prior to purchasing him. However, this is not always the case. Some previously purchased bulls will need to be test prior to February 1, 2020.

If GE-EPDs are needed, DNA testing should be purchased and ordered through the breed association in which the bull is registered. For example, DNA testing for an Angus bull should be purchased through Angus Genetics, Inc.

Do NOT purchase tests designed for commercial heifers (Igenity Beef, GeneMax Advantage, etc.).

Here is information on purchasing DNA testing for GE-EPDs for several common breed associations used in the program:

Angus
Contact AGI Customer Services at 816-383-5100 for assistance.
Submitting DNA Samples to Angus Genetics
Collecting DNA Samples
Testing Options



Red Angus
Contact RAAA National Office at (940) 387-3502 ext 8 for assista…

Show-Me-Select Rules Require Genomic Tested Bull EPDs

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New sire selection rules for Show-Me-Select Replacement Heifers improve reliable calving-ease genetics.

“Bulls used in the heifer program will carry DNA-tested EPDs (expected progeny differences),” said Jared Decker, University of Missouri Extension geneticist.

The rules going into effect Feb. 1, 2019, were set by the SMS governing board of farmers.
“DNA tests add reliability to EPDs for selecting herd bulls,” Decker said.

Bulls for pasture-breeding heifers will carry genomic-enhanced EPDs. In the past, EPDs were based on pedigree and production tests. “Now GE EPDs combine DNA, pedigree and production data into a single tool,” he said.

“DNA tests give results similar to 28 calving-ease production records,” Decker said. “More data boost confidence in a sire.”

With DNA tests, EPDs result from checking blood drops, tissue samples or hair root bulbs. Blood or tissue tests are preferred, Decker said. A one-time test adds data on young bulls equal to years of production testing. It lasts a lifeti…

Show-Me-Select Board Approves Genomic Testing Requirement for Natural Service Sires

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All bulls purchased after February 1st, 2019 for use as natural service sires in the Show-Me-Select Replacement Heifer Program™ must be DNA tested to have genomic-enhanced EPDs. All bulls used as natural service sires after February 1st, 2020 must have genomic-enhanced EPDs, regardless of when they were purchased. Seedstock producers classifying bulls as Show-Me-Select qualified in sale books must have genomic-enhanced EPDs on those lots.
Bulls purchased prior to February 1st, 2019 will be grandfathered into the program, as is the common practice with all natural service sires. However, this grandfather grace period will end February 1st, 2020. At that time for a bull to qualify for use in the program, it must have genomic-enhanced EPDs.

Why the change? The Show-Me-Select Replacement Heifer Program has the goal of producing premium heifers that perform predictably as 2 year olds. The program has a history of requiring Show-Me-Select producers to go beyond typical cattle production pr…