AgriLife Research projects evaluate feeder cattle on yeast-grain diet

Writer: Blair Fannin, 979-845-2259, [email protected]

Contact: Dr. Luis Tedeschi, 979-845-1541, [email protected]

COLLEGE STATION – Yeast is a staple ingredient found in many breads, but it also could play a major role in feeding cattle and producing higher quality beef.

Dr. Luis Tedeschi, Texas A&M AgriLife Research Faculty Fellow, and graduate student Whitney Crossland are studying the effects of yeast as part of an extensive fed-cattle study.

The study is in partnership with AB Vista of the United Kingdom. The goal of the project is to determine if yeast can be a viable replacement for ionophores and other antibiotics during the transition phase from feeding high-roughage to feeding high-grain diets in feedlot conditions.

The study involves feeding 120 steers both yeast- and non-yeast-based diets. Some are fed traditional grain diets without ionophores and antibiotics, while others are fed the same traditional grain diet with yeast added.

“With yeast, it forces us to look at alternative ways of feeding our animals,” Tedeschi said.

The work includes taking samples of rumen fluid and measuring rumen pH and temperature remotely through sensors. It also involves taking biometric body measurements on each animal and measuring physical composition of the body weight using 3-D images.

Ultimately, Tedeschi said the 3-D imaging research could also provide another method of identifying and sorting fed cattle as traditional methods involve measuring weight.

The research results could allow feedlot operators to select by physical frame composition and other metrics, allowing more efficient use of feed, cutting costs and achieving a goal of producing a higher yielding beef product, Tedeschi said.

“The reason we take biometrics is to better determine the composition of animals,” Tedeschi said. “We can single out both the fat and the protein throughout the study. At the end of the feeding study, all 120 animals will be harvested to determine body and carcass composition at the end. We are also studying the development of muscles and collecting rumen fluid to compare the effect of yeast versus non-yeast supplemented diets.”

The researchers are also using a sensor that is placed inside the rumen of the animal to measure pH, temperature and activity.

“We are also measuring microbiome to measure the yeast-based diet,” he said. “The feeder steers are on feed for an average of 220 to 225 days. We collect data from the start to finish of feeding.”

Tedeschi’s research has also been used in co-authoring a reference book, Nutrient Requirements of Beef Cattle, the eighth revised edition in the animal nutrition series. He was part of a committee that worked on four chapters regarding livestock animal nutrition. His research involves developing feeding models, including building upon previous work  with several software feeding models.

        A separate study Tedeschi is leading, funded by AgriLife Research, involves heat-stress diets in cattle. He said eight steers have been trained to go into a respiration chamber where he can measure energy expenditure, changes in respiration and rumen pH through a bolus sensor.

“The bolus sensor communicates to an antenna in the room and then to the cloud where we can collect real-time data. We will know the rumen temperature, pH levels, heat stress and water intake.”

“We want to model water intake based on ruminal temperature,” he said. “Normal temperature is 39-40 degrees. We also want to measure the temperature of the water and consumption.”

Overall, Tedeschi said the research projects are helping to develop sustainable livestock intensification.

“The yeast project really is a product to provide the same animal productivity with less use of antibiotics,” he said. “We are using biometrics to see which animals fit the higher U.S. Department of Agriculture grades. We also don’t want to keep them too long on feed or too short.

“The feed companies that would buy our system would have customized values of their feeds. In other words, they would have a better formulation of diets. This could also be applied to dairy animals, sheep and goats.”