Two trials were conducted, one using crossbred steers (Trial 1; N=275; 376±24 kg) and a second using Hereford heifers (Trial 2; N=5; 420±6 kg) to evaluate the performance, carcass quality, rumen fermentation and nutrient digestibility of cattle fed wheat or corn dried distillers grains with solubles (DDGS). The control ration averaged 87.7% rolled barley grain, 5.6% supplement and 6.8% barley silage (DM basis) over both trials. Dietary treatments included replacement of barley grain at 20 or 40% of the diet (DM basis) with wheat or corn DDGS. For Trial 1, steers were slaughtered at a constant finish weight of 645 kg. Data was analyzed as a completely randomized design using pen as the experimental unit. Feeding increasing levels of wheat DDGS quadratically increased dry matter intake (DMI) (P<0.01), whereas increasing levels of corn DDGS quadratically decreased DMI (P=0.01). Average daily gain was not influenced (P=0.13) by feeding wheat or corn DDGS but cattle fed corn DDGS exhibited a quadratic increase (P=0.01) in gain:feed. As a result, a quadratic increase (P<0.01) in calculated NEg of the diet was observed as corn DDGS levels increased. A linear decrease (P=0.04) in days on feed (169, 166 and 154 days) was noted when increasing levels of wheat DDGS (0, 20 and 40%) were fed. Dressing percentage increased in a linear fashion with wheat DDGS (P<0.01) inclusion level and in a quadratic fashion (P=0.01) as corn DDGS inclusion level increased although other carcass traits were not affected (P>0.10) by treatment.<p>
Trial 2 evaluated the effects of corn and wheat DDGS on rumen fermentation and nutrient digestibility parameters. Rumen pH, duration and area under rumen pH thresholds of 5.8, 5.5 and 5.2 were not affected (P>0.05) by treatment. Wheat DDGS inclusion increased (P=0.01) rumen ammonia-N levels in a linear fashion, while the inclusion of both wheat and corn DDGS resulted in quadratic (P=0.01) and linear (P=0.01) increases in butyrate concentration, respectively. Feeding corn DDGS also decreased total rumination time linearly (P=0.01) and DMI in a quadratic (P=0.04) fashion. Feeding wheat DDGS decreased (P=0.01) DM digestibility in a linear fashion. Wheat and corn DDGS inclusion quadratically increased (P=0.01) the digestibility of crude fat while feeding corn DDGS also linearly increased (P=0.01) the digestibility of crude protein. Neutral detergent fiber digestibility increased in a linear fashion (P=0.01) as both wheat and corn DDGS inclusion increased while ADF digestibility increased in a linear fashion (P=0.03) for wheat and in a quadratic (P=0.02) fashion for corn DDGS. The digestibility of both NDIN and ADIN increased (P=0.01) in a quadratic fashion for both corn and wheat DDGS inclusion level. Increased inclusions of wheat DDGS resulted in a linear decrease in gross energy digestibility (P=0.01), but neither wheat nor corn DDGS inclusion affected diet digestible energy content (P>0.05). Feeding both wheat and corn DDGS increased (P=0.01) the excretion of nitrogen and phosphorus.<p>
Replacement of barley grain with up to 40% corn or wheat DDGS improved gain:feed and reduced days on feed, respectively with no detrimental effect on carcass quality grade or sub-primal boneless boxed beef yield. The results of this project also indicate that the inclusion of corn and wheat DDGS (up to 40%) in feedlot rations does not mitigate ruminal acidosis, however the inclusion of both byproducts strongly impacts nutrient (crude fat, ADF, NDF, ADIN and NDIN) digestibility.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:SSU.etd-01292010-172749 |
| Date | 02 February 2010 |
| Creators | Walter, Lee-Anne Judy |
| Contributors | Yu, Peiqiang, Hendrick, Steve, McAllister, Tim, McKinnon, John, Mutsvangwa, Tim |
| Publisher | University of Saskatchewan |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-01292010-172749/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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