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Residual Feed Intake (RFI)

Residual feed intake (RFI) is an efficiency measurement that partitions feed intake into requirements for maintenance and growth, and is calculated by subtracting actual feed intake from expected feed intake. Therefore, more efficient animals have a negative RFI value and consume less than expected, while less efficient animals have a positive RFI value and eat more than expected. Heritability of RFI has been shown to be moderate at approximately 0.36 (36%). Research has also shown that selecting for RFI may result in as much as a 9-10% reduction in cow herd maintenance costs, a 10-12% reduction in feed intake, a 25-30% decrease in methane emissions and a 15-20% decrease in manure production.

The CGA office will be organizing a testing period at Olds College (dependent upon participation). The testing period will be approximately 50 days plus a minimum 14 day warm-up. In addition to having the GrowSafe feed bunks, Olds College has installed the GrowSafe Beef watering systems. These waterers measure a partial weight every time the animal stands on the system, and through calculations can predict a whole-body weight with high accuracy. This system has allowed the test period to be shortened significantly compared to the original 76-day period. Performance data generated includes daily feed intake, average daily gain, feed conversion, ultrasound and RFI. In addition, each animal will have a 50K DNA test completed to allow for genomically enhanced RFI EPDs.


GrowSafe Beef watering system

RFI feed bunks
The CGA office will provide reports on the following information:
  • Weights
  • ADG
  • Feed to Gain
  • Ultrasound results
  • RFI data

If you are interested in participating in an RFI test or have any questions please contact the office.

Ultrasound

Scanning should be completed by a certified technician and within the acceptable age range. The range for Canadian Gelbvieh animals is 320 to 410 days of age. Barn sheets will be required by the lab. You may generate these through your Digital Beef login. Contact the office with any questions.


Yearling Bulls

Weights – should be taken within 7 days of the scan date and preferably before morning feeding.

Gain - The best measure of a bull's propensity for marbling and muscle expression is when the bull is being fed to gain at least three pounds per day. Additionally, these tendencies will best be expressed at the end or near the end, of a post-weaning gain test.

Contemporary group – contemporaries must be from the same weaning contemporary group.

Replacement Heifers

Weights - should be taken within 7 days of the scan date and preferably before morning feeding.

Contemporary group – contemporaries must be from the same weaning contemporary group.

Feedlot Steers and Heifers

Scans - Feedlot animals should be scanned when the contemporary group averages 0.3 - 0.4 inches of external fat or just prior to slaughter.

Weights - should be taken within 7 days of the scan date and preferably before morning feeding.

Contemporary group – contemporaries must be from the same weaning contemporary group.

All animals within a contemporary group should be scanned on the same day or no more than three consecutive days.

Beef ultrasound measurements collected for each animal include:
  • Rump fat thickness
  • 12-13th rib fat thickness
  • Ribeye area
  • Percentage intramuscular fat (marbling)

EPDs

Expected Progeny Differences (EPDs)

EPDs are generated using the Single-Step Multi-breed Genetic Evaluation powered by BOLT by International Genetic Solutions (IGS). The new genetic evaluation provides more predictive EPDs, better use of genomics, more accurate accuracy reported with EPDs, all with weekly evaluations. Single-step uses DNA markers, pedigree information, and phenotypic data simultaneously in the prediction of EPDs. The BOLT single-step method only uses DNA markers that have a meaningful impact on the traits of interest, while ignoring those that have little to no effect, thereby increasing the accuracy of the EPD prediction. For more information on the individual trait evaluations and indexes please go to the CGA website.

Genomically Enhanced EPDs

Genomically enhanced EPDs are EPDs that are calculated while factoring in a high density genomic profile on the animal. Animals with genomically enhanced EPDs have their EPDs displayed on Digital Beef with a yellow highlight. Providing a high density genotype allows for increased accuracy in the EPD evaluation, just as an increase in the number of progeny and their performance data increases the EPD evaluation on a given sire or dam. The table below is a display of estimated progeny equivalents. An estimated progeny equivalent is the average number of progeny records it would take to see an equivalent change in accuracy from a genomic test. Over time these estimates will change as the statistical models improve, the number of phenotypes reported increase, and genomic data improves.
Example: If Sire A has no progeny reported to him and he is genotyped with a high density profile, then the accuracy of his EPD is the same as having over 25 calves with a calving ease direct record.

EPD trait definitions

DNA Testing

Please ensure that you have reviewed the CGA DNA regulations and that all of your animals comply with the DNA requirements. All DNA samples are to mailed directly to the lab at the address below. Before mailing your sample ensure that you have made your DNA requests through the CGA office.

DNA Regulations

Mailing Samples

Please mail your samples directly to the lab.
Neogen Canada
7323 Roper Road NW
Edmonton, AB T6E 0W4
* When mailing your samples be sure to indicate that you are a CGA member on your sample envelopes. Also be sure to include your information and return address. When labelling your sample envelopes with the animals tattoo, please ensure you are labelling your tattoo accurately, the same as you have recorded in Digital Beef. Without all of this information, the lab will not be able to find your DNA request orders coming from the CGA office.

Taking Samples

Samples must be submitted via hair card, blood card, or tissue sampling unit (TSU). You can get these supplies directly from Neogen Canada by contacting Michelle Miller at MMiller@neogen.ca. You will be billed directly from Neogen Canada for these supplies.

• Blood cards $0.25/card
• Hair cards $0.50/card
• TSU $2.25/tube, come in boxes of 10
• TSU applicator $45.00

Submitting DNA Requests

You must make your DNA requests through the CGA office before mailing your samples directly to the lab. All DNA tests have a 21 day turnaround time. Delays in turnaround time may occur if you have not submitted your requests before the samples arrive at the lab. You can make your requests online through Digital Beef or using the below DNA request form.

Male Fertility Research Project

The purpose of this research project is to better understand what male fertility traits are most critical to getting cows bred, better understand the genetic relationships between male fertility and other economically relevant traits, and to prototype a genetic evaluation for the most important traits. The goals of the project are as follows.

  • Evaluate the impact of male fertility on conception rates and develop a prototype sire conception rate EPD for beef cattle
  • Provide a prototype for evaluation of male fertility in beef bulls utilizing semen quality metrics from AI studs and BSE evaluations of natural service sires
  • Identify and validate QTL and genetic variants predictive for male fertility component traits
  • Estimate genetic correlations between semen quality parameters and growth, reproductive and carcass traits

Please use the following link to record your breeding soundness data and submit it to the CGA office. You can record breeding soundness data from older, previously tested bulls and bulls you are currently going to get tested. Recording the same bull from year to year is also encouraged.

CLICK HERE TO DOWNLOAD DATA SPREADSHEET

Why participate?

Those who participate will have access to the data and conclusions made from the research project. Participants will also have access to the EPD evaluations developed. Being involved from the ground up will give the CGA the opportunity to publish the evaluation as soon as it becomes available, as our data will have already been collected.