title: Microbial release of ferulic and p-coumaric acids from forages and their digestibility in lactating cows fed total mixed rations with different forage combinations.
abstract: BACKGROUND
  Ferulic acid (FA) and p-coumaric acid (PCA) are widely distributed in graminaceous plant cell walls. This study investigated the in vitro and in vivo digestibility of ester-linked FA (FAest) and PCA (PCAest) in lactating dairy cows.
  
  
  RESULTS
  Regarding corn stover, ensiled corn stover, whole corn silage, Chinese wild ryegrass and alfalfa hay with different phenolic acid profiles, the in vitro rumen digestibility of forage FAest and PCAest was negatively correlated with the ether-linked FA content and original PCA/FA ratio in the forages. The concentration of both phenolic acids in culture fluids was low after a 72 h incubation, and the mixed rumen microorganisms metabolized nearly all phenolic acids released into the culture fluids. FAest digestibility in the whole digestive tract was negatively correlated with dietary PCA/FA ratio, but a converse result occurred with dietary PCAest digestibility. The digestibility in either the rumen or the whole digestive tract was greater for FAest than for PCAest.
  
  
  CONCLUSIONS
  Forage PCAest in comparison with FAest is not easily digested in either the rumen or the whole digestive tract, and they were negatively affected by forage FAeth content and lignification extent indicated by the original dietary PCA/FA ratio.
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
authors: Bin-Bin
authors: BB
authors: Cao
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
authors: Xin
authors: X
authors: Jin
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
authors: Hong-Jian
authors: HJ
authors: Yang
authors: State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, China.
authors: Sheng-Li
authors: SL
authors: Li
authors: Beijing Key Laboratory for Dairy Cow Nutrition, Beijing University of Agriculture, Beijing, 102206, China.
authors: Lin-Shu
authors: LS
authors: Jiang
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D002417:Cattle / Q000378:metabolism*; D003373:Coumaric Acids / Q000378:metabolism*; D004032:Diet / Q000662:veterinary; D004063:Digestion; D005260:Female; D007774:Lactation / Q000502:physiology; D008129:Lolium / Q000737:chemistry; D000455:Medicago sativa / Q000737:chemistry; D011422:Propionates; D012417:Rumen / Q000382:microbiology*; D012820:Silage; D003313:Zea mays / Q000737:chemistry
chemical_list: D003373:Coumaric Acids; D011422:Propionates; C004999:ferulic acid; C495469:p-coumaric acid
keywords: digestibility; ferulic acid; forage; p-coumaric acid