High-tech feed bunks help rank bull efficiency

GrowSafe tests bulls’ residual feed intake and has compiled a database with more than a quarter million cattle

GrowSafe published its first public list of proven, feed-efficient bulls earlier this year.

“It isn’t technically the most efficient 150 bulls, it’s the highly proven, most proven 150 bulls on our database,” said Mark Nelson of GrowSafe.

GrowSafe tests bulls’ residual feed intake (RFI), which is a measure of feed efficiency, and has compiled a database with more than a quarter million cattle from multiple breeds that have expected progeny differences (EPD) data.

EPDs are estimates of an animal’s genetic merit as a parent, and GrowSafe requires three generations of parental information to ensure reliable ratings.

“We calculate EPDs for them and any animal that reaches an accuracy of .6 or higher then becomes part of our public list of the high accuracy efficiency tested bulls we have EPDs on,” Nelson said.

He said that level of accuracy is required so producers can count on the rating.

“Those numbers aren’t going to change much even if you start sending in more data, because it’s a very proven animal at that point.”

The GrowSafe system has two configurations. The first uses RFID ear tags and scaled feed bunks that send data to a central computer to gauge how much an animal is eating and gaining.

Nelson said 70 days’ worth of data is required to run a trial with this system.

The second system also measures feed intake with RFID ear tags and scaled feed bunks but uses an in-pen weighing system at the waterer. Trials can be completed in 49 days because the weight measurements are more accurate.

“We can measure gain more accurately in a less amount of time with those daily weights than if we’re using chute weights over a longer period of time,” Nelson said.

In Canada, most GrowSafe systems are used at bull test stations to gather data on feed intake and gain.

The information is analysed by GrowSafe, which Nelson said provides a third-party impartial analysis.

“RFI takes into account the difference in age and weight of the test animals. So if you have differences in individual growth and maintenance needs, an RFI removes those differences from animal to animal. So it’s a pure way to look at efficiency of gain,” Nelson said.

An animal with a high positive RFI needs more feed to gain the same amount as its peers, while an animal with a negative RFI eats less to gain the same amount as its peers.

Nelson said producers should consider RFI in combination with gain if they want a better look at total profitability. RFI by itself shows efficiency of gain but it doesn’t indicate whether the animal is a big or a small gainer.

Both RFI and gain numbers are provided on the top bull list.

Researchers have selected bulls with low RFI values for decades.

“We’ve been doing this for about 20 years, and we’ve been focusing on purebred seed stock cattle,” said Tommy Perkins of West Texas A&M University, who uses the GrowSafe system.

He looks for bulls that have the best combination of low intake with rapid gain.

“The guys that were buying bulls 20 years ago, they stacked generation upon generation of feed efficient cattle that certainly has improved their bottom line,” said Perkins, noting the savings in feed costs.

He said the system can also be used to find feed efficient heifers to help build the herd.

Carolyn Fitzsimmons, a research scientist with Agriculture Canada, said studies at the University of Alberta’s Kinsella Ranch, led by Dr. John Basarab, found low RFI animals had a tendency for low carcass weights, and heifers with a low RFI reached puberty later compared to high RFI heifers.

“Which makes sense because animals that have a leaner carcass have less fat and the fat is where all the steroid hormones are produced,” Fitzsimmons said.

However, researchers also found that if they adjusted RFI data for back fat at the end of the test, the relationship between low RFI and later puberty disappeared.

“So far we think that pretty much negated any negative effects on reproduction to be associated with RFI. You can still have heifers that are still reaching puberty early and having a low RFI,” she said.

Fitzsimmons led a long-term study at Kinsella Ranch on economically important cattle traits.

“Researchers saw no effects on maternal productivity traits including age at first calving, calving dates, pregnancy, calving and weaning rates and no adverse effects on calf performance traits including birth/weaning weights and both pre- and post-weaning daily gain,” according to the study’s conclusion.

When RFI is corrected for back fat, it eliminates any relationship between RFI and leanness in heifers and bulls.

She said more long-term research into RFI and the relationships to other economically important traits is needed to ensure there are no adverse effects. She added that RFI should not be the only factor in selection.

Perkins said producers were initially concerned that using RFI would select for small-framed cattle but tests showed feed-efficient cattle in all frame sizes.

“We also found that, having collected enough carcass data, that we can find cattle that are efficient that still excel in carcass merit. They have ample quality grade and they will be good yielding cattle,” Perkins said.

GrowSafe customers have received lists of the top bulls for three years, but this is the first time a list has been made available to the public.

You can see the list online here.

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