Three experiments were conducted to investigate the effects of various cereal grain types on the production performance of dairy cattle and the colonization of <i>Clostridium perfringens</i> in the intestinal tract of cattle. The first experiment investigated the effect of feeding two different cultivars of barley (cv. Harrington and Valier) and two different cultivars oat (cv. Derby and AC Assiniboia) grain on feed intake, milk yield and milk constituents. It was found that barley or oat may both be successfully incorporated into the concentrate portion of western Canadian dairy rations. NRC Dairy 2001 predictions for both oat and barley diets very closely predicted dry matter intake and milk production. AC Assiniboia oat fed cows produced the lowest percentage of fat (P<0.05) compared to the other dietary treatments. Oat fed cows produced milk with lower total solids (P<0.05) than barley fed cows. Experiment two investigated the effect of replacing barley with corn in the concentrate of a dairy ration on performance parameters as well as fecal shedding of <i>C. perfringens</i>. Corn can successfully replace a portion of the cereal grain in a typical western Canadian dairy ration without adverse effects on milk production, feed intake and feed efficiency. Corn fed cows produced significantly higher milk protein than barley fed cows (P<0.05). Dairy NRC 2001 milk production predictions were similar to observed milk yields. Mean (±SEM) level of colonization (log cfu/g) of <i>C. perfringens</i> in the feces was lower (P<0.05) in barley-fed (1.30±0.27) compared with corn-fed (2.47±0.27) cows. Experiment three was a survey to determine the level of shedding of <i>C. perfringens</i> in feces of dairy cattle at different ages and stages of lactation and in feedlot cattle through the backgrounding and finishing phases. No relationship was found between heifer age and level of shedding or between days in lactation and level of shedding. Sixteen percent of the sampled cows exhibited high levels of shedding (3.02±.46) log cfu/g feces) through all stages of lactation without exhibiting adverse effects on health. No relationship was found between age of heifer and level of <i>C. perfringens</i> shedding in the feces. Steers shed significantly higher (P<0.05) levels of <i>C. perfringens</i> during the last phase of finishing compared with other feeding phases. Further research investigating <i>C. perfringens</i> colonization in cattle is required.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-07242007-151330 |
| Date | 03 August 2007 |
| Creators | Meier, Julie-Anne |
| Contributors | Van Kessel, Andrew G., Rossnagel, Brian G., McKinnon, John J., Christensen, David A. |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-07242007-151330/ |
| 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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