Following the Beef Improvement Federation (BIF) conference last week in Lincoln, Neb., two bus-loads of attendees participated in a one-day tour, visiting Circle 5 feedlot, GeneSeek and the U.S. Meat Animal Research Center (MARC) near Clay Center.

The MARC facility includes 34,000 acres, of which about 22,000 acres are grazing land for the center’s 7,200 cows and 2,000 ewes. A 6,000-head feedlot on the property finishes all the calves from the center’s herd.  

Of the cows the center manages, about 2,400 are part of the Germplasm Evaluation (GPE) project, a long term genetic evaluation of 18 breeds of cattle managed by geneticist Mark Thallman, PhD. The project uses representative AI bulls from each breed and collects extensive performance and carcass data to characterize genetic traits within breeds, and uses extensive crossbreeding to develop models for predicting heterosis.

Remaining cows on the operation are a commercial cow herd, many of which are the MARC II composite breed developed at the center using Angus, Hereford, Simmental and Gelbvieh.

The station uses an intensive grazing system, moving herds of cattle to fresh forage every one or two days during the peak growing season Chad Engle, livestock operations manager for the center, says the staff has worked with livestock-handling experts to incorporate low-stress practices into their herding routines, with excellent results in terms of overall cattle disposition.

The MARC feedlot collects performance data, including individual feed-intake data for an ongoing national feed-efficiency study. Some of the work there supports the GPE project while researchers also conduct independent trials relating to animal health, performance, welfare, nutrition and food safety. A trial currently underway is exploring breed interactions with the use of the beta agonist Optaflexx.

Another beta agonist study underway at the center will provide a detailed evaluation of cattle fed Zilmax, which is temporarily off the market while researchers investigate concerns over animal welfare. MARC researchers are collecting extensive data on a variety of health and behavior factors on treated and control cattle in this trial.

The researchers divided cattle in the test into a light block, that will finish early this summer and heavy block that will finish later, likely experiencing more hot days late in the finishing period. Half the cattle in the test are black-hided and the other half are colored, also as a means to evaluate heat stress and possible interactions with the beta agonist. At the beginning of the study, researchers recorded locomotion scores for all the cattle as they walked them to the processing area. During processing they listened to their respiration rates and recorded lung scores, and recorded flight speeds as cattle left the chute. They are monitoring body temperatures using electronic rumen boluses that transmit temperatures to an RFID antenna every 10 seconds. They also are collecting blood and fecal samples for analysis.

The researchers plan to repeat the behavioral tests such as locomotion scoring at the end of the finishing period, and follow the cattle through processing to make similar observations during transport, the holding period and processing at the plant. The trial, they say, should help determine whether the use of the beta agonist is associated with any changes in cattle mobility or disposition late in the feeding period through processing.