Effect of Yeast Culture Supplementation on the Performance of High Risk Beef Cattle

Document Type


Degree Name

Master of Science (MS)


Ag Science and Natural Resources

Date of Award

Spring 2018


Yeast supplementation of stocker cattle entering the feedlot have shown to increase gain,average daily gain (ADG), dry matter intake (DMI), and feed efficiency (FE) as well asminimize the number of sick days. Supplementing high-risk beef cattle with yeast culture couldhave implications of increasing performance although the animal is expected to have decreasedperformance. The purpose of this study was to evaluate the effect of yeast culturesupplementation on the gain, ADG, DMI, and FE of weaned, high-risk beef cattle (HRBC) whenfed a transition ration. One hundred heifers comingled at Texas A&M-Commerce for 1 weekprior to the start of the study. Heifers were stratified by weight and randomly assigned into 20pens (N = 20); 5 animals per pen. The control group (CTRL; n = 10) received a grain mixtureconsisting of ground flax seed, soy hull, dried distiller's grains, corn, cotton seed hull, and avitamin and mineral premix. The treatment group (YEAST; n = 10) received the same grainmixture except the premix included RYEAST 40 (ICC-USA, INC., Louisville, KY 40202) to be fed at the rate of 9 g/hd/d. Each head received 7 lb/d of concentrate and supplemented with 2%body weight of hay from local sources. Cattle were fed the ration for 42 days with weightsrecorded every 7 days. Gain, ADG, and FE were compared on a pen basis utilizing the PROCMIXED procedure of SAS (SAS 9.3 SAS Institute Inc; Cary, NC, Ver 9.3). Significance wasdetermined at p ï‚£ 0.05. Gain, ADG, FE, and DMI between CTRL and YEAST was notsignificantly different (p > 0.05). The data did not show a benefit of supplementing yeast culturesto increase performance outcomes of HRBC. Further research should be completed in order toinvestigate if higher dosages of yeast can affect performance.


Douglas Eborn

Subject Categories

Agriculture | Animal Sciences | Life Sciences