233 Comparison of Intramuscular fat Deposition in Different Muscles of Beef Cattle

Abstract Two groups (light = 740 lbs and heavy 942 lbs) of Akaushi cross steers (n 20), were ultrasounded for carcass traits by an Ultrasound Guidelines Council Certified Technician every 28 days to quantify differences in intramuscular fat deposition occurring three distinct muscles (longissimus dorsi, biceps femoris semitendinosus). Cattle fed at the West Texas A&M University Research Feedlot scanned with Aloka 500 ultrasound unit using Beef Image Analysis (BIA) software from Designer Genes Technologies, Inc. (Harrison, AR). Carcass measurements included 12-13th rib ribeye area (REAU), subcutaneous thickness (FTU), percentage along longissimus dorsi (IMFULD), rump (RFU) as well (IMFUBF) semitendinosus (IMFUST). A difference was detected IMFULD duration study (P < 0.05). However, no occurred day 0 56 0.34), or 84 140 0.17) IMFULD. There a slight numerical decrease (0.1505%) IMFUBF 56, increased positive change 4.113% 5.728% group 0.08) 4.456% light 0.42) IMFUBF. significant IMFUST Of note, there IMFULD, IMFST 168 which could be associated adverse winter weather events. The data present increase throughout all studied beef cattle while on feed, though events have possibility negatively affect gains more rapidly than progressive effects feed growth.