Please use this identifier to cite or link to this item:
https://hdl.handle.net/1959.11/3858
Title: | Effect of Dietary Fiber on Endogenous Nitrogen Flows in Lactating Dairy Cows | Contributor(s): | Ouellet, D R (author); Demers, M (author); Zuur, G (author); Lobley, G E (author); Seoane, J R (author); Nolan, John Vivian (author) ; Lapierre, H (author) | Publication Date: | 2002 | Handle Link: | https://hdl.handle.net/1959.11/3858 | Abstract: | The effect of dietary fiber on endogenous N secretion was studied using a ¹⁵N isotope dilution technique in four fistulated Holstein cows. Two isonitrogenous diets differing only in fiber (NDF and ADF) content were used in a crossover design. One diet (HF) contained 37.4% NDF, while the other (LF) contained 23.3%. A new model was developed to estimate endogenous N secretions and losses for the preintestinal, intestinal, and the total sections of the gastrointestinal tract. Three precursor pools: TCA-soluble fraction of plasma, intestinal mucosa, and milk were compared. Although endogenous losses estimated with the model were numerically different for each precursor pool selected (TCA-soluble fraction > mucosa > milk), treatment effects were similar. As intestinal mucosa is probably closest to the precursor pool, these data are discussed. Non-urea N endogenous secretions contributed 13% of the duodenal N flow but were not affected by the fiber content of the diet. The nonurea N endogenous flow at the duodenum was comprised of approximately equal inputs from endogenous N direct, and that incorporated into the microbial biomass. Total endogenous N flows at the duodenum exceeded, by nearly twofold, estimated inputs of urea-N to microbial biomass. Metabolic fecal output averaged 17% of fecal N and was not affected by level of dietary fiber, but net losses from secretions occurring in the small intestine were higher with the low fiber diet. Overall, endogenous N secretions represented 30% of total digestive tract protein synthesis. | Publication Type: | Journal Article | Source of Publication: | Journal of Dairy Science, 85(11), p. 3013-3025 | Publisher: | Elsevier Inc | Place of Publication: | United States of America | ISSN: | 1525-3198 0022-0302 |
Fields of Research (FoR) 2008: | 070204 Animal Nutrition | Socio-Economic Objective (SEO) 2008: | 830302 Dairy Cattle | Peer Reviewed: | Yes | HERDC Category Description: | C1 Refereed Article in a Scholarly Journal | Publisher/associated links: | http://jds.fass.org/cgi/reprint/85/11/3013.pdf http://www.dairy-science.org/cgi/content/abstract/85/11/3013 |
---|---|
Appears in Collections: | Journal Article |
Files in This Item:
File | Description | Size | Format |
---|
Page view(s)
1,090
checked on Apr 7, 2024
Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.