Changes in the rumen papillae during the periparturient transition in Holstein dairy cows are accompanied by changes in abundance of proteins involved in intracellular pH regulation, but not SCFA transport

• Author(s) / Creator(s)

  • McBride, Brian W.
  • Laarman, Anne H.
  • Steele, Michael A.
  • AlZahal, Ousama
  • Kleinberg, Adam

• The objective of this study was to examine changes in SCFA transportcapacity in the rumen epithelium during the parturition transition period.Twelve pregnant, cannulated primiparous and multiparous cows were fed astandard Total Mixed Ration (TMR) for the duration of the dry period; aftercalving, all cows were switched to an early lactation TMR. Rumen pH, fluid andbiopsies were taken 3 weeks before anticipated calving (PRE), 1 week afteractual calving (PERI) and 6 weeks after calving (POST). Rumen biopsies wereanalyzed for transport protein abundanceusing immunofluorescence. Immunofluorescence analysis showed no significantchanges in the abundance of monocarboxylate co-transporter, isoform 1 among thePRE, PERI and POST periods (16878±1555 A.U., 15613±1508 A.U. and 16886±1555A.U. respectively; MCT1). Also, sodium/proton exchanger, isoform 3 (NHE3) wasnot significantly different among the PRE, PERI and POST periods (10467±1066A.U., 9465±1066 A.U., 8552±1109 A.U., respectively). Sodium/Bicarbonate Co-transporter,isoform 1 (NBC1) was likewise unaffected by time, with the protein abundanceamong PRE, PERI and POST parturitionperiods changing from 16467±1274 A.U., 13983±1318 A.U. and 15047±1324 A.U.,respectively. Abundance of Carbonic Anhydrase, isoform 2 (CA2) decreased from12332±1580 A.U (PRE) to 7235±1580 (PERI) and 8121±1643 (POST) and this decreasewas significant (P = 0.01 PRE v. PERI). The observed changes in proteinabundance suggest that long-term adaptation of the rumen epithelium occurs toincrease transport capacity. Decreased CA2 abundance suggests thatintracellular acidification is occurring as part of epithelial remodelling.Taken together, this implies that, during the periparturient transition, adecrease in rumen pH leads to a decrease in intracellular pH in the rumenepithelium, promoting epithelial remodelling that result in increased SCFAtransport capacity.

• Date created

  2015

• Subjects / Keywords

  • Epithelial Remodelling
  • Transport Capacity
  • Periparturient Transition
  • Rumen Epithelium

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3CZ32J5G

• License

  Attribution 4.0 International