Steers (n = 80; initial BW 271 ± 99) were serially scanned at 42-d intervals during a 378-d feeding period using an Aloka 500 device by a certified Ultrasound Guidelines Council (UGC) technician using real-time ultrasound. This included 10 separate ultrasound scanning sessions following the initial weight and ultrasound data taken on day minus 7 (one week prior to initial start date). Steers were randomly assigned to implant treatment (either implanted with Revalor XS or not) at day -7. Cattle were weighed and scanned for 12th-rib fat thickness (FTU), 12th-rib longissimus muscle area (LMAU), percentage intramuscular fat (%FATU), and rump fat thickness (RFU) to determine the ability of ultrasound to predict carcass grading outcomes at harvest. Scans were processed by CUP Lab technicians. Eight steers were harvested each 42 days. Carcasses were assessed 48h after harvest to determine 12th-rib fat thickness (FTC), 12th-rib longissimus muscle area (LMAC), and marbling score (MARB). Data were analyzed via Pearson correlation and linear regression to determine the relationship of ultrasound measures to carcass outcomes. Positive correlations (P < 0.01) between ultrasound measures taken the day before harvest and carcass measurements indicated strong relationships between FTU and FTC (r = 0.91), LMAU and LMAC (r = 0.93), and moderately strong relationships between %FATU and MARB (r = 0.76). Prediction equations were generated to estimate FTC = .0088 + (1.02585 x FTU), LMAC = 16.29720 + (0.77197 x LMAU) and MARB = 19.87510 + (5.19832 x %FATU). Results suggest real-time ultrasound data provides an effective tool to estimate carcass outcomes pre-harvest.

Bovine liver abscess outcomes of individual animals (n = 989,296) were observed from 2013 to 2021 on a pen (n = 6,420) basis to quantify liver abscess prevalence and severity, as well as other liver abnormalities such as liver flukes. Cattle originated from 122 feedlots located in Arizona, Colorado, Idaho, Kansas, Minnesota, Missouri, Nebraska, Oklahoma, and Texas. Livers were audited at eighteen different beef abattoirs. Observational categories included sex (heifer, steer), cattle type (Holstein, beef-type), and pen count. Pen counts were grouped (< 40, 41–80, 81–160, 161–320, and >320) to quantify the association of pen size on liver abscess outcomes. Data were analyzed as a series of binomial proportions using generalized linear mixed models with fixed effects of observational categories (cattle type, feedyard location, pen size and sex). Cattle fed in Oklahoma or Texas exhibited greater (P < 0.01) frequency of liver flukes (3.2% vs 0.5%) than cattle fed in Colorado or Nebraska. Cattle fed in Colorado, Kansas, Missouri, Nebraska, Arizona, and Oklahoma exhibited fewer (P < 0.01) total abscesses (23.5%, 26.0%, 23.6%, 19.3%, 16.9%, and 18.1%) than cattle fed in Idaho, Minnesota, and Texas (36.4%, 36.4%, and 33.2%). Beef-type cattle were observed to exhibit fewer (P < 0.01) total abscesses (22.0% vs 41.1%) and fewer (P < 0.01) severe abscesses (10.2% vs 26.4%) than Holstein cattle. Likewise, native heifers exhibited fewer (P < 0.01) total abscesses (20.6% vs 23.3%) and fewer (P < 0.01) severe abscesses (9.3% vs 11.1%) than native steers. Abscess prevalence differed as a function of pen size. Both total abscess and severe abscess rates decreased (P < 0.01) as animal count within a pen increased (32.66%, 27.47%, 27.86%, 23.17%, and 20.33%; 17.20%, 14.48%, 14.80%, 11.45%, and 9.14%). These results suggest liver abscess prevalence and severity is affected by a wide range of factors.

The association of lung abnormalities with carcass performance was evaluated on data from 60,843 carcasses housed in the West Texas A&M University Beef Carcass Research Center database collected from 2010 to 2021 to quantify the relationship of lung health and carcass performance. Lung outcomes were scored as severity of consolidation (N = Normal and free of consolidation, 1 = 5 to 15% consolidation, 2 = 15 to 50% consolidation, 3 = >50% consolidation) and presence of fibrin tags (M = Minor fibrin, E = Extensive fibrin). Lung consolidation had a strong and detrimental effect (P < 0.01) on hot carcass weight, with lung scores of 1, 2, and 3 resulting in 4.2, 13.3, and 29.9 kg less carcass weight compared with carcasses with normal lungs. Minor and extensive fibrin tags (3.5 kg and 7.1 kg), independent of consolidation, resulted in lighter carcasses (P < 0.01) compared with those with normal lungs. Lung score did not have an effect on marbling score. Both lung tissue consolidation and fibrin tags effected 12th rib fat thickness; lung consolidation (-0.09 to -0.21 cm) and fibrin tags (-0.14 to -0.19 cm) resulted in and less (P < 0.01) 12th rib fat thickness compared with carcasses with normal lungs. Similarly, LM area was reduced (P < 0.01) in carcasses with lung consolidation (-1.5 to -5.5 cm2) or presence of fibrin tags (-2.3 to -2.7 cm2) compared with carcasses with normal lungs. Additionally, severity of lung consolidation and presence of fibrin tags reduced (P < 0.01) calculated yield grade; lung consolidation and fibrin tags resulted in a 0.08 to 0.20 and 0.09 to 0.13 reduction in overall yield grade. These data indicate that lung health is an important factor that impacts carcass performance, particularly carcass weight and yield grade parameters.