title: Dietary nitrate supplementation reduces methane emission in beef cattle fed sugarcane-based diets.
abstract: The objective of this study was to determine the effect of dietary nitrate on methane emission and rumen fermentation parameters in Nellore × Guzera (Bos indicus) beef cattle fed a sugarcane based diet. The experiment was conducted with 16 steers weighing 283 ± 49 kg (mean ± SD), 6 rumen cannulated and 10 intact steers, in a cross-over design. The animals were blocked according to BW and presence or absence of rumen cannula and randomly allocated to either the nitrate diet (22 g nitrate/kg DM) or the control diet made isonitrogenous by the addition of urea. The diets consisted of freshly chopped sugarcane and concentrate (60:40 on DM basis), fed as a mixed ration. A 16-d adaptation period was used to allow the rumen microbes to adapt to dietary nitrate. Methane emission was measured using the sulfur hexafluoride tracer technique. Dry matter intake (P = 0.09) tended to be less when nitrate was present in the diet compared with the control, 6.60 and 7.05 kg/d DMI, respectively. The daily methane production was reduced (P < 0.01) by 32% when steers were fed the nitrate diet (85 g/d) compared with the urea diet (125 g/d). Methane emission per kilogram DMI was 27% less (P < 0.01) on the nitrate diet (13.3 g methane/kg DMI) than on the control diet (18.2 g methane/kg DMI). Methane losses as a fraction of gross energy intake (GEI) were less (P < 0.01) on the nitrate diet (4.2% of GEI) than on the control diet (5.9% of GEI). Nitrate mitigated enteric methane production by 87% of the theoretical potential. The rumen fluid ammonia-nitrogen (NH(3)-N()) concentration was significantly greater (P < 0.05) for the nitrate diet. The total concentration of VFA was not affected (P = 0.61) by nitrate in the diet, while the proportion of acetic acid tended to be greater (P = 0.09), propionic acid less (P = 0.06) and acetate/propionate ratio tended to be greater (P = 0.06) for the nitrate diet. Dietary nitrate reduced enteric methane emission in beef cattle fed sugarcane based diet.
authors.affiliation: Provimi Holding B.V., Research Centre De Viersprong, Veilingweg 23, 5334 LD, Velddriel, the Netherlands. rhulshof@nl.provimi.com
authors.forename: R B A
authors.initials: RB
authors.lastname: Hulshof
authors.forename: A
authors.initials: A
authors.lastname: Berndt
authors.forename: W J J
authors.initials: WJ
authors.lastname: Gerrits
authors.forename: J
authors.initials: J
authors.lastname: Dijkstra
authors.forename: S M
authors.initials: SM
authors.lastname: van Zijderveld
authors.forename: J R
authors.initials: JR
authors.lastname: Newbold
authors.forename: H B
authors.initials: HB
authors.lastname: Perdok
mesh_terms: D000641:Ammonia / Q000737:chemistry; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle / Q000502:physiology*; D018592:Cross-Over Studies; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D008697:Methane / Q000737:chemistry / Q000378:metabolism*; D009566:Nitrates / Q000737:chemistry / Q000494:pharmacology; D012417:Rumen / Q000502:physiology; D031786:Saccharum; D013459:Sulfur Hexafluoride; D014508:Urea / Q000737:chemistry / Q000494:pharmacology
chemical_list: D009566:Nitrates; D000641:Ammonia; D014508:Urea; D008697:Methane; D013459:Sulfur Hexafluoride