If picking out your next car, one you would be driving for the next seven years, what type of car would you choose? Would you pick a SUV that averages 9-13 miles per gallon or a four-door sedan that averages 24-30 mpg? In essence, livestock producers are faced with similar decisions with their animals. (Paisley et al)
Improving the feed efficiency of a beef cattle herd can mean big savings for producers. Feed is a major cost in animal production, second only to capital costs. Since 2007 feed prices have been unpredictable at best. It is likely that feed prices will continue to rise, linked to fuel and fertilizer prices.
On average, it costs $50 less over 112 days to feed an efficient bull compared to an inefficient one. An efficient bull will pass on superior genetics for feed efficiency to his progeny, which will be realized as feed savings for calves in the feedlot and for replacement heifers entering the cowherd.
Residual Feed Intake (RFI)
In 1963 Residual Feed Intake (RFI) was first proposed as a measure of livestock feed efficiency by US researchers (Koch et al). To calculate RFI requires the measurement of actual individual animal feed intake. The concept of RFI offered huge potential but on a commercial scale lay dormant until GrowSafe developed fully automated feed intake measurement systems reliable enough to be used in a typical livestock production environment.
Residual feed intake (RFI) represents the amount of feed consumed, net of the animals requirements of body weight and production. Efficient animals eat less than expected and have a negative or low RFI, while inefficient animals eat more than expected and have a positive or high RFI.
There is conclusive scientific evidence that cattle with low RFI consume less feed at the same level of production as high RFI cattle. In addition to reducing feed consumption, cattle with low RFI produce less methane from enteric fermentation and also less manure relative to high RFI cattle, due to the fact they consume less feed. (Arthur 2009)
Benefits of selection for lower RFI in beef cattle:
- Reduction in feed intake by 10-12%
- Reduction in liver, stomach and intestinal weights
- 25-30% reduction in methane production
- 15-17% reduction in manure N, P and K production
- Efficient calves become efficient adults
- Progeny of low RFI cattle more efficient (Agri-facts)
- GrowSafe Standardized Measurement
In collaboration with global animal scientists, GrowSafe has developed a method for feed intake measurement over a standardized test period to measure and calculate RFI. Data acquisition is standardized across tests, and GrowSafe measurement and RFI calculations are third party validated.
A network of research facilities, ranches, feedlot and seedstock test stations supply GrowSafe RFI measured feed efficient sires, semen from certified feed efficient sires, and progeny for sale to producers, ranches, auction barns, feedlots and other buyers. There are now more than 55 academic and research institutions using GrowSafe technology and more than 16 commercial facilities. In 2010, more than 28000 North American bulls were GrowSafe RFI tested.
GrowSafe RFI Testing
GrowSafe testing exceeds the minimum feed intake guidelines established by the Beef Improvement Federation, and published Breed Association rules. GrowSafe has developed compliance software which ensures adherence to test rules.
A conditioning warm up-period establishes that all animals are acclimated to test conditions. Test duration is 70 days. Intake measurements taken by GrowSafe are required for a minimum of 50 days of “good days” within the 70 day test period. Days where bulls are treated for sickness, removed from the pen for any reason (e.g., ultrasound, weights, etc.) are not be counted as a “test day”. In sickness cases, full ad libitum intake will have resumed before data collection continues.
All bulls or progeny within one test are fed the same test diet, and the diet is formulated to provide appropriate levels of energy to ensure expression of animal differences for intake. The ingredient composition of the diet is recorded. Random samples of the diet are sent to a commercial laboratory for complete chemical analysis. All ingredient and chemical compositions of the diet are done on a dry matter basis.
Age on Test
Animals entering a test facility have birth and weaning date recorded. From this information and a contemporary group definition, animals within a feeding group should have a start of test age that is within a 90 day range. Pen of feeding also forms a component of the test contemporary group. Individual feed intake data is collected on animals within the range of weaning age to not more than 460 days of age.