| Q: |
Which feed efficiency analyses are available from IGENITY? |
| A: |
Producers can evaluate two traits related to feed efficiency and growth with IGENITY — residual feed intake (RFI) and average daily gain (ADG). RFI, also called net feed efficiency, describes how an animal's feed intake differs from its expected feed intake based on its maintenance and growth requirements.1 |
| Q: |
Are either RFI or ADG more important when evaluating feed efficiency? |
| A: |
RFI is the most powerful predictor of an animal's ability to convert feed efficiently because it takes into account the animal's maintenance and growth requirements. However, the ability to evaluate animals for both RFI and ADG is a powerful opportunity for producers in all segments. An efficient animal is only valuable, and profitable, if they also perform or grow, which is why it is important that producers consider both analyses. And, IGENITY is the only tool available for producers to evaluate cattle for both of these traits early in every stage of production.1 |
| Q: |
Is a higher score for RFI more desirable or lower? |
| A: |
As with all of the other analysis available from IGENITY, RFI is scored on a 1 to 10 scale. A higher score means more of the trait. Therefore, a low score for RFI is more desirable than high RFI, since a low-RFI animal will either eat less with the same gains or gain more from the same amount of feed. |
| Q: |
How were the analyses for RFI researched and validated? |
| A: |
The RFI analyses from IGENITY are the most researched feed efficiency-related analyses available.2,3 Before they were submitted for external validation, they were evaluated in populations that included more than 1,000 head of cattle. These populations represented Bos taurus breeds and crossbred cattle. Once the RFI analysis for Bos taurus cattle were found to be powerful in these populations they were evaluated by the National Beef Cattle Evaluation Consortium (NBCEC). This third-party group also found them to be powerful predictors of feed efficiency. |
| Q: |
How do the analyses from IGENITY for RFI compare with others commercially available? |
| A: |
An independently conducted head-to-head study at the University of Guelph also proved the analysis for RFI from IGENITY for Bos taurus cattle is more predictive of an animal's genetic potential for this trait than analyses from all other DNA technology providers. In addition, only the analysis from IGENITY for Bos indicus cattle has been proven to accurately predict feed efficiency in this type of cattle. 2,3 |
| Q: |
Why is it important to have separate analysis for Bos indicus and Bos taurus breeds? Which one should producers use who have crossbred cattle that include both breed types? |
| A: |
IGENITY is the only DNA technology provider that offers separate analyses for RFI for both Bos incidus and Bos taurus cattle. These are complex traits, and enough differences have been found between the two groups that it is important to offer separate analyses for both breed types. If producers have crossbred cattle that include both Bos indicus and Bos taurus breeds, they should use the analysis for Bos indicus cattle |
| Q: |
Which breeds are considered Bos indicus and Bos taurus? |
| A: |
Bos indicus breeds are the eared, or Brahman-type, cattle. Bos taurus breeds are the English and continental breeds such as Angus, Hereford, Simmental and Gelbvieh. |
1Carstens GE, Tedeschi LO. Defining feed efficiency in beef cattle. Presentation at Beef Improvement Federation Conference. 2006. Available at: http://www.bifconference.com/bif2006/pdfs/Carstens.pdf. Accessed May 26, 2008.
2Data on file at Merial.
3National Beef Cattle Evaluation Consortium Web site. Available at: http://www.nbcec.org. Accessed February 22, 2009.
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