title: Alfalfa nutritive quality for ruminant livestock as influenced by ambient air quality in west-central Alberta.
abstract: Alfalfa (Medicago sativa) nutritive quality response to ambient ozone (O(3)), sulfur dioxide (SO(2)) and oxides of nitrogen (NO(x)) were assessed at three locations in west-central Alberta, Canada (1998-2002). Yield data were segregated into high and low relative to overall median yield. Ozone concentrations (hourly median and 95th-percentile) and precipitation (P) contributed 69 and 29%, respectively, to the variability in crude protein (CP) concentration in low-yielding alfalfa, whereas mean temperature (T) and relative humidity (RH) collectively influenced 98% of the variation in CP in high-yielding alfalfa. Three-fourths of the accounted variation in relative feed value (RFV) of low-yielding alfalfa was attributable to P, T and RH, whereas median and 95th-percentile hourly O(3) concentrations and SO(2) and NO(x) exposure integrals contributed 25%. In contrast, air quality, (mainly O(3)) influenced 86% of the accounted variation in RFV of high-yielding alfalfa, and T and P collectively contributed 14%.
authors.affiliation: Department of Animal Sciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Lin
authors.forename: M
authors.initials: M
authors.lastname: Nosal
authors.forename: R B
authors.initials: RB
authors.lastname: Muntifering
authors.forename: S V
authors.initials: SV
authors.lastname: Krupa
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D000416:Alberta; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000829:Animals, Domestic / Q000378:metabolism*; D018533:Biomass; D004044:Dietary Proteins / Q000032:analysis; D006813:Humidity; D000455:Medicago sativa / Q000502:physiology*; D009589:Nitrogen Oxides / Q000009:adverse effects; D009753:Nutritive Value; D010126:Ozone / Q000009:adverse effects; D012418:Ruminants / Q000378:metabolism*; D012820:Silage; D013458:Sulfur Dioxide / Q000009:adverse effects; D013696:Temperature
chemical_list: D000393:Air Pollutants; D004044:Dietary Proteins; D009589:Nitrogen Oxides; D013458:Sulfur Dioxide; D010126:Ozone