Feed efficiency data plays an important part in genetic research

BY : MICHAEL J. THOMAS

 

Data collected from feed efficiency trials continues to play a large role in research aimed to improve the cattle industry.  Discoveries, based on these trials, have made positive differences in all aspects of the industry: from the cow/calf operator to the feedlot.

Dr. John Hall, superintendent of the Nancy M. Cummins Research Extension Education Center (REEC) said, “We’ve done a variety of feed efficiency related research using the GrowSafe™ system over the years.”

Dr. Hall explained that they have run feed efficiency trials on Wagu bulls and heifers for agri-beef companies in the past, and have been working with the American Simmental Association’s carcass merit system for the past four years.

The Nancy M. Cummins REEC uses Simmental bulls on their cows. They do feed intake studies on all of the steers, before they go to the feedlot, and then share that information with the American Simmental Association. This information is then input into the large body of data used to generate EPD’s for the American Simmental Association.

Another ongoing trial involves the center’s heifer calves. All of the heifers go through feed efficiency testing.

Dr. Hall said, “We are keeping track of the lifetime performance of those heifers, as it relates to feed efficiency, as well as the reproduction efficiency of those heifers as productive cows – a combined study.”

The Nancy M. Cummins REEC has collected about five years feed efficiency data on these heifers. This will be an ongoing and long term study following these heifers through their lives as productive cows.

Dr. Hall said, “Some of the work we have done on the reproduction side is showing a slight advantage to the inefficient heifers in terms of reproductive performance. At this point we can’t say that the inefficient heifers are negatively affected in terms of reproduction. I don’t think we can make that  statement. We have seen some trends that the inefficient heifers are heifers that reach puberty a little earlier. They don’t  necessarily have a better or worse pregnancy rate. That’s kind of an interesting aspect of the research. We are continuing this research, because at this point we don’t have the answer one way or the other.”

The data collected to this point of the trial, while limited, suggests that the inefficient heifers reach puberty earlier, or cycle earlier than the efficient heifers. “If we think about that from a biological perspective, the efficient heifers are probably partitioning more of the nutrients toward growth, where the inefficient heifers have more of their nutrients available for reproduction,” said Dr. Hall.

All of the heifers in the trials have been estrus synchronized and artificially inseminated. To date the trials have not shown a difference in conception rates, short or long term, but more testing will be required to determine if this is affected by synchronizing and AI-ing the animals.

A relatively new facet of the trials involves following these cows through their productive lives on different pasture environments. The recent acquisition of the Rock Creek Ranch, near Hailey, Idaho, allows the Nancy M. Cummins REEC to
split the herd and run half of the mother cows in a more traditional Idaho range environment, while the other half remains at the center on irrigated pasture.

Using feed efficiency information that was gathered on the heifers at the Nancy M. Cummins REEC, Dr. Jim Sprinkle has been running a trial to find out if the first-calf heifers and young cows that are efficient use the range differently than young heifers and cows that are inefficient. This involves using GPS collars on the heifers and young cows to see how those animals utilize the range.

Dr. Hall said, “Looking at lifetime productivity is going to take us awhile. We have efficiency testing that was done when they were heifers, and now they are four and five year old cows. It’s going to take us  awhile to look at the longevity side of things, unless there is something that is really dramatic.”

As cow/calf operators have come to trust and rely on other genetically predictable traits, the ability to predict the fertility and longevity of a mother cow will be very important to cow/calf producers. Many of us in the industry will be curious to follow the results of the trials on the Nancy M. Cummins REEC mother cows.

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