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Effect of processing method on in sacco ruminal degradability of organic matter and nitrogen from canola seeds and in vitro intestinal nitrogen digestion of the in sacco residue

Author:
Gunter, S. A., Springer, T. L., Loest, C. A., Goldman, J. J.
Source:
Animal production science 2014 v.54 pp. 1030
ISSN:
1836-0939
Subject:
Brassica napus, canola, cattle, energy intake, grazing, grinding, nitrogen, organic matter, pastures, rolling, rumen, rumen fermentation, seed scarification, seeds, testa
Abstract:
A novel crop on the Southern Plains of the United States is canola (Brassica napus L.), of which annual production has nearly doubled in the last 5 years. Although production has not exceeded the demand for oil, the question has arisen as to its supplemental value for cattle grazing the rangeland adjacent to production areas. In an experiment, six seed processing methods were evaluated by in sacco digestion of organic matter and nitrogen and in vitro intestinal in sacco residue: (1) whole seeds with no processing; (2) seed coats scarified in a pneumatic seed scarifier; (3) ground in a four-knife mill; (4) unprocessed seed rolled to 0.5 mm thick; (5) seeds roasted then rolled to 0.5 mm thick; and (6) steamed then rolled to 0.5 mm thick. Processing methods were compared with a solvent-extract canola seed meal. All processing methods increased in sacco organic matter and nitrogen digestion in the rumen with ground method being the greatest (P < 0.05). These results showed that the ground method produced the most (P < 0.05) ruminally degraded nitrogen/kilogram of organic matter digested in the rumen (67 g) of all methods evaluated. Further, extent of in vitro nitrogen digestion (intestinal) from in sacco residue was reduced by increases in ruminal digestion. Processing methods that broke the seeds increased (P < 0.05) the total extent of nitrogen digestion over whole and scarified treatments. The most limiting nutrient to augment energy intake and digestion in cattle grazing native pastures is ruminally degraded nitrogen and it seems that the most appropriate processing method is grinding to use whole canola seeds as a supplement. Other processing methods evaluated either increased processing cost or increased the ruminally undegraded nitrogen value.
Handle:
10113/59327