Healthy, docile and black-hided calves outperform others in the feedlot.
Iowa State University Extension and Certified Angus Beef feedlot specialists teamed up to summarize the feedlot performance, carcass characteristics and profitability factors from eight years (2002-2009) of the Iowa Tri-County Steer Carcass Futurity. From their closeout data, more than 47,000 steers and heifers originating from 19 states were evaluated for disposition, health status, hide color, percentage Angus and origin.
A similar diet was fed and similar implant, vaccination and health programs were administered to all calves within four days of feedlot arrival. A minimum 28-day preconditioning period was required prior to feedlot delivery. Cattle were sorted and slaughtered when visually estimated to have 0.4 in. of back fat.
The calves were scored for temperament 3-4 times during the feeding period and divided into disposition groups: docile (DC), restless (R), and nervous to very aggressive (NVA). All disposition groups had similar feedlot arrival weight.
DC calves had the highest average daily gain (ADG), while NVA calves had the lowest – 3.20 vs. 3.02 lbs./day, respectively.
Slaughter and carcass weight of DC calves was 15 and 7 lbs. greater, respectively, than R calves, and 40 and 17 lbs. greater than NVA calves.
Marbling score and quality grade were negatively affected by a poor temperament. The DC group had double the number of calves grading Certified Angus Beef (CAB) than the NVA group, 21% vs. 9%. DC calves were more profitable than R or NVA calves – $46 vs. $26 vs. $8 /head, respectively. Feedlot performance and profitability can be impacted by replacement bull and female selection, because temperament is moderately heritable.
The effects of health status were evaluated by classifying calves into three groups: never-treated (NT), treated once (1T) and treated multiple times (2T). Calves in the 2T group were treated an average of 2.6 times while in the feedlot. The cost of treatment medication averaged $24 and $61/head for the 1T and 2T groups.
ADG was lowest for calves in the 2T group and highest for the calves never treated. The 2T calves gained 0.3 lb./day slower and required an additional 17 days on feed to reach the slaughter target. Marbling score and quality grade were negatively impacted by health status.
Among all calves, researchers determined that 4% had lung adhesions (a portion of the lung adhered to the thoracic cavity) at slaughter. In addition to the negative effects of health status, cattle with lung adhesions have reduced dressing percentage. Profitability was $70 and $190/head less in 1T and 2T calves vs. NT calves, respectively.
On arrival at the feedlot, calves were classified as black-hided or non-black-hided and the percentage Angus determined based on sire and dam information. The percentage of Angus was classified as low (L), half (H), three-quarters (3/4) and straight (S).
Black-hided calves gained 0.13 lb./day faster, required nine fewer days on feed to reach slaughter, had fewer health treatments and had 1.1% lower death loss than non-black-hided calves.
Black-hided calves had higher marbling scores and graded 72% vs. 54% Choice but were higher in percentage of yield grade 4 and 5 carcasses, 2.7 vs. 1%.
Among Angus calves, as the percentage of Angus increased, ADG increased, days on feed decreased, and marbling score, percent Choice and percent CAB increased; however, the percent of yield grade 4 and 5 carcasses also increased.
Calves from 12 Southeast (SE) and seven Midwest (M) states were compared for origin differences. SE calves were older at delivery, 10.5 vs. 8.5 months, respectively, and 20 lbs. heavier. M calves required more health treatments and had a 0.5% higher death loss.
ADG and quality grade were similar between groups. SE calves consumed more feed but required seven fewer days to reach their slaughter endpoint. SE calves were $14/head more profitable than M calves.
Scott B. Laudert, Ph.D., is a beef cattle technical consultant and former Kansas State University Extension livestock specialist. Contact him at 719-660-4473.