Two trials were carried out to evaluate the effect of inclusion level of canola meal derived from Brassica (B.) napus and B. juncea on cattle performance and nutrient utilization. Trial 1 consisted of backgrounding (54 d) and finishing (153 d) phases. The control diet for the backgounding (BK) phase consisted of 39% barley silage, 30.4% barley grain, 22.8% brome grass hay and 7.8% supplement (DM). Treatments consisted of B. napus or B. juncea at 15 or 30% (DM) inclusion, replacing barley grain. The finishing control diet consisted of 88.3% barley grain, 4.4% barley silage and 7.3% supplement (DM). Treatments consisted of B. napus or B. juncea at 10 or 20% (DM) inclusion, replacing barley grain. During BK, dry matter intake (DMI), average daily gain (ADG), gain: feed (G:F) increased linearly (P < 0.01) as the level of inclusion of B. juncea meal increased. Cattle fed B. napus meal showed a quadratic response (P = 0.05) in DMI and linear increase (P = 0.02) in ADG with increasing inclusion. During finishing, DMI increased linearly (P = 0.05) for cattle fed B. juncea meal while a quadratic response (P = 0.02) was seen with B. napus meal. Feed efficiency and NEg content of the diet (P ≤ 0.02) decreased linearly with increasing inclusion of both meals. Trial 2 evaluated dietary rumen fermentation and total tract digestibility characteristics in a 5 x 5 Latin Square Design. Diets were similar to finishing phase of Trial 1. There was no effect of treatment on rumen pH, however a linear increase in acetate (P ≤ 0.01), ammonia (P < 0.01) and decrease (P < 0.01) in propionate was seen with both meal types. Crude protein and acid detergent fiber digestibility increased (P = 0.03) linearly with increasing inclusion of B. juncea meal. The results indicate that canola meal derived from B. napus and B. juncea is not suitable as a supplemental energy source replacing for barley grain in finishing diets but canola meal from B. juncea can be fed at levels up to 30% of the DM in backgrounding diets if priced appropriately.
| Identifer | oai:union.ndltd.org:USASK/oai:ecommons.usask.ca:10388/ETD-2013-12-1354 |
| Date | 2013 December 1900 |
| Contributors | McKinnon, John J. |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text, thesis |
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