Abstract #866

# 866
Effects of chromium propionate in combination with yeast on growth performance and carcass quality of finishing steers.
Cadra L. Van Bibber-Krueger*1, Justin E. Axman1, John M. Gonzalez1, Jim S. Drouillard1, 1Kansas State University, Manhattan, KS.

A combination of chromium propionate and yeast supplement (CrY; TruMax, Varied Industries Corp., Mason City, IA) was added to diets of crossbred steers (n = 504; 402 ± 5.8 kg initial BW) to evaluate the effect on feedlot performance and carcass quality. Steers were selected on the basis of initial plasma glucose concentrations ≤6.0 mM, stratified by initial BW, blocked into heavy (H; 420 kg BW) and light (L; 384 kg BW) groups, and assigned to treatments of 0 (CON) or 3.3 g/d CrY (provided 0.5 mg Cr/kg diet DM) with 6 pens/diet within each block. Body weights were measured at 21-d intervals. Finished cattle were weighed and transported to a commercial abattoir where severity of liver abscesses and HCW were collected at harvest, and yield and quality grades, LM area, and 12th rib subcutaneous fat thickness were determined after 36 h of refrigeration. There were no CrY × time × weight block interactions for ADG, DMI, and G:F (P = 0.36; P = 0.49; P = 0.41, respectively), and no CrY × block interactions for ADG and DMI (P = 0.06; P = 0.75, respectively), but a CrY × block interaction (P = 0.03) was observed for G:F; CON-L had poorer efficiency compared with other groups. Yield grade and marbling score tended to be less (P > 0.07) for CrY compared with CON, but other carcass measurements were unaffected by treatment (P > 0.30). Chromium propionate in combination with yeast may improve feed efficiency of lighter cattle, but other effects were minimal. Table 1. Feedlot performance and carcass traits of steers
DMI, kg/d12.5712.2913.0012.830.17
ADG, kg/d1.701.761.881.840.03
HCW, kg3984004084073.65
LM area, cm288.1390.0693.1092.970.96
12th rib fat, cm1.301.
Yield grade2,32.792.532.662.660.07
Marbling score3,44594534304146.54
1CrY × weight block interaction (P = 0.03). 2CrY × weight block interaction (P = 0.08). 3Effect of CrY (P ≤ 0.08). 4Marbling score determined by camera imaging; Small = 400 to 499.

Key Words: beef cattle, chromium propionate, glucose