title: Feed-derived volatile basic nitrogen increases reactive oxygen species production of blood leukocytes in lactating dairy cows.
abstract: The present study investigated over 9 months the changes of fermentative quality of total mixed rations (TMR) containing grass silage (GS) as a major component, associated with changes in the volatile basic nitrogen (VBN) levels in an experimental dairy farm. Effects of VBN levels in TMR on metabolic parameters, reactive oxygen species (ROS) production by blood polymorphonuclear leukocytes (PMNs) and conception rates for dairy cows were analyzed. According to VBN levels in TMR during survey periods, three distinct phases were identified; phase A with low VBN; phase B with high VBN; and phase C with mid-VBN. Metabolic parameters in blood were all within normal range. However, during phases B and C, nitrogen metabolic indices such as blood urea nitrogen and milk urea nitrogen showed higher levels compared to those in phase A, and a simultaneous increase in ROS production by blood PMNs and the load on hepatic function in metabolic parameters was observed in the cows with a lower conception rate. This suggests that feeding TMR with elevated VBN levels due to poor fermented GS results in stimulation of ROS production by PMNs by ammonia, and negatively affects metabolism and reproductive performance in lactating dairy cow.
authors.affiliation: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.|Field Center of Animal Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
authors.forename: Ei
authors.initials: E
authors.lastname: Tsunoda
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Josef J
authors.initials: JJ
authors.lastname: Gross
authors.affiliation: Field Center of Animal Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Kawashima
authors.affiliation: Veterinary Physiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Rupert M
authors.initials: RM
authors.lastname: Bruckmaier
authors.affiliation: Field Center of Animal Agriculture, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kida
authors.affiliation: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Miyamoto
mesh_terms: D000818:Animals; D001806:Blood Urea Nitrogen; D002417:Cattle / Q000378:metabolism* / Q000502:physiology*; D003612:Dairying; D005260:Female; D005285:Fermentation; D005306:Fertilization; D008892:Milk / Q000737:chemistry; D009504:Neutrophils / Q000378:metabolism*; D009584:Nitrogen / Q000009:adverse effects* / Q000032:analysis*; D006109:Poaceae; D017382:Reactive Oxygen Species / Q000097:blood* / Q000378:metabolism*; D012820:Silage / Q000009:adverse effects / Q000032:analysis; D014835:Volatilization
chemical_list: D017382:Reactive Oxygen Species; D009584:Nitrogen
keywords: dairy cow; liver function; poor fermented silage; reactive oxygen species; volatile basic nitrogen