title: Feeding a high-concentrate corn straw diet induced epigenetic alterations in the mammary tissue of dairy cows.
abstract: OBJECTIVE
  The objective of this study was to investigate the effects of feeding a high-concentrate corn straw (HCS) diet (65% concentrate+35% corn straw) on the epigenetic changes in the mammary tissue of dairy cows in comparison with a low-concentrate corn straw (LCS) diet (46% concentrate+54% corn straw) and with a low-concentrate mixed forage (LMF) diet (46% concentrate+54% mixed forage).
  
  
  METHODS
  Multiparous mid-lactation Chinese Holstein cows were fed one of these three diets for 6 weeks, at which time blood samples and mammary tissue samples were collected. Mammary arterial and venous blood samples were analyzed for lipopolysaccharide (LPS) concentrations while mammary tissue samples were assayed for histone H3 acetylation and the methylation of specific genes associated with fat and protein synthesis.
  
  
  RESULTS
  Extraction of histones and quantification of histone H3 acetylation revealed that acetylation was significantly reduced in cows fed the HCS diet, as compared with cows fed the LCS diet. Cows fed the HCS diet had significantly higher LPS concentrations in the mammary arterial blood, as compared with cows fed the LCS diet. We found that the extent of histone H3 acetylation was negatively correlated with LPS concentrations. The methylation of the stearoyl-coenzyme A desaturase gene associated with milk fat synthesis was increased in cows fed the HCS diet. By contrast, methylation of the gene encoding the signal transducer and activator of transcription 5A was reduced in cows fed the HCS diet, suggesting that feeding a high-concentrate corn straw diet may alter the methylation of specific genes involved in fat and protein synthesis in the mammary tissue of dairy cows.
  
  
  CONCLUSIONS
  Feeding the high-concentrate diet induced epigenetic changes in the mammary tissues of dairy cows, possibly through effecting the release of differing amounts of LPS into the mammary blood.
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: Guozhong
authors.initials: G
authors.lastname: Dong
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: Min
authors.initials: M
authors.lastname: Qiu
authors.affiliation: College of Animal Science, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China.
authors.forename: Changjin
authors.initials: C
authors.lastname: Ao
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: College of Animal Science, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China.
authors.lastname: Khas-Erdene
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Animal Science and Technology, and Key Laboratory of Grass and Herbivores of Chongqing, Southwest University, Beibei, Chongqing, China.
authors.forename: You
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000821:Animal Feed / Q000009:adverse effects; D000818:Animals; D002417:Cattle; D003612:Dairying; D044127:Epigenesis, Genetic / Q000187:drug effects*; D005260:Female; D006657:Histones / Q000378:metabolism; D008070:Lipopolysaccharides / Q000097:blood; D008321:Mammary Glands, Animal / Q000187:drug effects*; D003313:Zea mays / Q000009:adverse effects*
chemical_list: D006657:Histones; D008070:Lipopolysaccharides