title: Short communication: Effect of subacute ruminal acidosis on in situ fiber digestion in lactating dairy cows.
abstract: Subacute ruminal acidosis (SARA) was induced by replacing 25% of the total mixed ration intake [dry matter (DM) basis] with pellets consisting of 50% wheat and 50% barley. This reduced dietary forage content (DM basis) from 39.7 to 29.8% and increased the dietary concentrate content from 60.3 to 70.2%. Induction of SARA reduced the 24- and 48-h in situ neutral detergent fiber (NDF) degradabilities of grass hay numerically from 31.5% to 24.6% (P = 0.29) and from 51.3% to 36.9% (P < 0.05), respectively. The 24- and 48-h in situ NDF degradabilities of legume hay were reduced from 35.3 to 26.3% (P < 0.05) and from 49.0 to 35.8% (P < 0.05), respectively. The 24- and 48-h in situ NDF degradabilities of corn silage were reduced from 44.0 to 37.2% (P < 0.05) and from 56.1 to 44.8% (P < 0.05), respectively. This study suggests that induction of SARA by excess feeding of wheat/barley pellets reduces the rumen digestion of NDF from grass hay, legume hay, and corn silage.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, ON, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Krajcarski-Hunt
authors.forename: J C
authors.initials: JC
authors.lastname: Plaizier
authors.forename: J P
authors.initials: JP
authors.lastname: Walton
authors.forename: R
authors.initials: R
authors.lastname: Spratt
authors.forename: B W
authors.initials: BW
authors.lastname: McBride
mesh_terms: D000138:Acidosis / Q000378:metabolism / Q000662:veterinary*; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002417:Cattle; D018592:Cross-Over Studies; D004043:Dietary Fiber / Q000008:administration & dosage / Q000378:metabolism*; D004063:Digestion; D007887:Fabaceae / Q000378:metabolism; D005260:Female; D001467:Hordeum; D007774:Lactation; D006109:Poaceae / Q000378:metabolism; D011897:Random Allocation; D012417:Rumen / Q000378:metabolism*; D012820:Silage; D014908:Triticum