title: The potential of 3-nitrooxypropanol to lower enteric methane emissions from beef cattle.
abstract: This study evaluated if 3-nitrooxypropanol reduces enteric methane (CH4) emissions when added to the diet of beef cattle. The effects of 3-nitrooxypropanol on related variables including diet digestibility, ruminal fermentation, and ruminal microorganisms were also investigated. Eight ruminally cannulated Angus heifers (549 ± 64.3 kg [mean BW ± SD]) were fed a high forage diet (backgrounding diet) supplemented with 4 levels of 3-nitrooxypropanol (0, 0.75, 2.25 and 4.50 mg/kg BW). The experiment was designed as a duplicated 4 × 4 Latin square with 2 groups of heifers and four 28-d periods. Methane emissions were measured during 3 consecutive days using metabolic chambers. Up to a 5.8% reduction in ad libitum DMI was observed when 2.5 mg/kg BW of 3-nitrooxypropanol was fed (P = 0.03). Increasing level of 3-nitrooxypropanol linearly (P < 0.001) reduced CH4, with 33% less CH4 (corrected for DMI) at the highest level of supplementation compared with the control. Feed energy lost as CH4 was also reduced when 3-nitrooxypropanol was supplemented (P < 0.001). Molar proportion of acetate was reduced (P < 0.001) and that for propionate increased (P < 0.001) with increasing dose of 3-nitrooxypropanol, which in turn led to a reduction in the acetate to propionate ratio (P < 0.001). Total copy numbers of 16S ribosomal RNA (rRNA) genes for bacteria, methanogens, and 18S rRNA genes for protozoa in ruminal contents were not affected by 3-nitrooxypropanol supplementation (P ≥ 0.31). There was no effect of 3-nitrooxypropanol on DM (P = 0.1) digestibility in the total tract. The use of 4.5 mg/kg BW of 3-nitrooxypropanol in beef cattle consuming a backgrounding diet was effective in reducing enteric CH4 emissions without negatively affecting diet digestibility.
authors.affiliation: Lethbridge Research Center, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1, Canada Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Romero-Perez
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
authors.forename: E K
authors.initials: EK
authors.lastname: Okine
authors.affiliation: Lethbridge Research Center, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1, Canada.
authors.forename: S M
authors.initials: SM
authors.lastname: McGinn
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
authors.forename: L L
authors.initials: LL
authors.lastname: Guan
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Oba
authors.affiliation: DSM Nutritional Products France, Research Center for Animal Nutrition, BP170, 68305 Saint Louis Cedex, France.
authors.forename: S M
authors.initials: SM
authors.lastname: Duval
authors.affiliation: DSM Nutritional Products France, Research Center for Animal Nutrition, BP170, 68305 Saint Louis Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Kindermann
authors.affiliation: Lethbridge Research Center, Agriculture and Agri-Food Canada, Lethbridge, AB T1J 4B1, Canada karen.beauchemin@agr.gc.ca.
authors.forename: K A
authors.initials: KA
authors.lastname: Beauchemin
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004063:Digestion / Q000187:drug effects*; D005285:Fermentation; D008697:Methane / Q000378:metabolism*; D009566:Nitrates / Q000494:pharmacology*; D020005:Propanols / Q000494:pharmacology*; D012417:Rumen / Q000378:metabolism
chemical_list: D009566:Nitrates; D020005:Propanols; D008697:Methane
keywords: 3-nitrooxypropanol; beef cattle; enteric methane emissions