Date of Award
Master of Science
Mark P Hoffman
In the first year, of this three-year study, 112 crossbred feeder-calf steers of primarily British breed origin (initial BW= 264 ± 10kg) were randomly assigned to four treatments (4 pens per treatment; 7 steers per pen; 28 steers per treatment) to determine the effects of feeding condensed corn distillers solubles (CCDS) on animal performance, carcass characteristics and economic performance in either a drylot or pasture feeding system. Weight, coat color and temperament of the steers were evenly distributed among treatments.
The first of these treatments was classified as the feedlot (F) group and contained animals that were immediately placed into a drylot and given a diet of shelled corn, alfalfa hay, protein, vitamin, and mineral supplements, as well as molasses. The second treatment group, feedlot + CCDS (F+CCDS), was also placed directly into a drylot and fed the same diet as F except for receiving CCDS in place of molasses. Treatments three and four were classified as pasture (P) and pasture + CCDS (P+CCDS). The P treatment cattle were placed on a 24 paddock (0.69ha/paddock) rotationally grazed smooth bromegrass pasture from May through September then fed a diet identical to group F upon entering the drylot in the fall. Cattle in the P+CCDS treatment were also allotted to the rotationally grazed pasture system but were allowed free choice access to CCDS via a lick tank. After being moved to the drylot in the fall their diet was then identical to the F+CCDS group.
In the second year of the study, a fifth treatment was added. This group, classified as pasture finished + CCDS (PF+CCDS), was raised on pasture for the entire study and fed shelled corn, a protein, vitamin, and mineral supplement and free choice CCDS. During
these trials, animal performance was measured through analysis of daily DMI/steer in the drylot, rate of gain, and feed efficiency in the drylot. Cattle weights were taken every 28 days while consumption of feed was measured daily. Cattle were harvested with an average ending weight of 590 ± 10kg and carcass data for presence of liver abscesses, hot carcass weight, ribeye area and backfat were obtained. Percent KPH, yield grades and quality grades were provided by certified USDA graders.
Average beginning weights and harvest weights were similar among treatments but differences were seen when comparing the number of days on feed (P<0.05). Cattle placed directly in the drylot setting, whether receiving CCDS or not, took less time to reach their target end weight than any of the pasture-fed treatments.
The P+CCDS treatment had a higher ADG (P<0.05) while on pasture than steers allotted to the P group however, ADG was similar between these groups when examining the drylot period and overall ADG. It was also shown that P and P+CCDS treatments tended to consume more feed when in drylot than F and F+CCDS cattle but no difference (P>0.05) in feeding efficiency was observed when comparing treatment P to treatment F. Cattle that were finished on pasture had a higher overall ADG (P<0.05) when compared to other pasture treatments but lower ADG (P<0.05) than both F and F+CCDS with a difference of 0.08 and 0.12 kg, respectively.
When evaluating carcass characteristics, cattle in treatment group F tended to have more backfat (P<0.05) than other groups. The cattle on the PF+CCDS treatment had a lower percentage of low Choice carcass grades or higher (P<0.05) than all other groups within this study. No differences (P>0.05) were seen in hot carcass weight, ribeye area, or KPH.
Corn costs were highest (P<0.05) for the F treatment and lowest (P<0.05) for the P+CCDS treatment. The F+CCDS treatment group was proven to have the greatest returns to management (P<0.05) when considering both the actual prices paid and also when accounting for typical prices paid over a ten year cattle feeding cycle.
Overall this study showed benefits for incorporating CCDS into cattle rations when feeding in either a drylot or pasture system, however, the greatest advantage was obtained by F+CCDS. This treatment exhibited improved ADG and feed efficiency as well as demonstrated the greatest amount of profitability.
Faithe Elizabeth Doscher
Doscher, Faithe Elizabeth, "The effects of feeding condensed corn distillers solubles in pasture vs feedlot settings on steer performance and carcass composition" (2012). Graduate Theses and Dissertations. 12316.