title: The effects of feeding 3-nitrooxypropanol on methane emissions and productivity of Holstein cows in mid lactation.
abstract: The objective of the current study was to determine the effects of adding 3-nitrooxypropanol to the diet of lactating Holstein cows on methane emissions, rumen fermentation, ruminal microbial profile, and milk production. Twelve ruminally cannulated Holstein cows in midlactation were used in a crossover design study with 28-d periods. Cows were fed a diet containing 38% forage on a dry matter basis with either 2,500 mg/d of 3-nitrooxypropanol (fed as 25 g of 10% 3-nitrooxypropanol on silicon dioxide) or 25 g/d of silicon dioxide (control). After a 21-d diet adaptation period, dry matter intake (DMI) and milk yield were recorded daily. Rumen fluid and digesta were collected on d 22 and 28 for volatile fatty acid analysis and microbial profiling. Enteric methane emissions were measured on d 23 to 27 using the sulfur hexafluoride tracer gas technique. Feeding 3-nitrooxypropanol did not affect DMI; however, methane production was reduced from 17.8 to 7.18 g/kg of DMI. No change in milk or milk component yields was observed, but cows fed 3-nitrooxypropanol gained more body weight than control cows (1.06 vs. 0.39 kg/d). Concentrations of total volatile fatty acids in ruminal fluid were not affected by treatment, but a reduction in acetate proportion and a tendency for an increase in propionate proportion was noted. As such, a reduction in the acetate-to-propionate ratio was observed (2.02 vs. 2.36). Protozoa counts were not affected by treatment; however, a reduction in methanogen copy count number was observed when 3-nitrooxypropanol was fed (0.95 vs. 2.69 × 10(8)/g of rumen digesta). The data showed that feeding 3-nitrooxypropanol to lactating dairy cows at 2,500 mg/d can reduce methane emissions without compromising DMI or milk production.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Haisan
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
authors.forename: L L
authors.initials: LL
authors.lastname: Guan
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Beauchemin
authors.affiliation: Agriculture and Agri-Food Canada, Swift Current, Saskatchewan S9H 3X2, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Iwaasa
authors.affiliation: DSM Nutritional Products Ltd., Centre de Recherche en Nutrition Animale, 1 Bd d'Alsace, Village-Neuf BP 170, France.
authors.forename: S
authors.initials: S
authors.lastname: Duval
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada.
authors.forename: D R
authors.initials: DR
authors.lastname: Barreda
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta T6G 2P5, Canada. Electronic address: moba@ualberta.ca.
authors.forename: M
authors.initials: M
authors.lastname: Oba
mesh_terms: D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005260:Female; D005285:Fermentation; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008697:Methane / Q000378:metabolism*; D020005:Propanols; D012417:Rumen / Q000378:metabolism
chemical_list: C000603069:3-nitrooxypropanol; D005232:Fatty Acids, Volatile; D020005:Propanols; D008697:Methane
keywords: 3-nitrooxypropanol; enteric methane emission; methanogen; milk production