title: Effects of feed and water deprivation on ruminal characteristics and microbial population of newly weaned and feedlot-adapted calves.
abstract: Two experiments were conducted to determine the effects of length of feed and water deprivation on ruminal microbes and ruminal characteristics. In Exp. 1, treatments were as follows: 1) weaned, but not trucked (0 h), 2) weaned, trucked, and fasted for 48 h (48 h), and 3) weaned, trucked, and fasted for 72 h (72 h). On d 0 (arrival back at the feedlot after treatment), DMI, ruminal contents (P < .05) decreased as length of feed and water deprivation increased. However, on d 4, there were no longer any differences (P > .10) in DMI or weight of ruminal contents. On d 0, percentage of ruminal DM in the 48- and 72-h treatment groups was lower (P < .01) than in the 0-h treatment group, but there were no differences (P > .10) by d 4. After the steers used in Exp. 1 had been in the feedlot for 28 h, they were reallotted, and the three treatments (except for weaning) were repeated; the 0-h group remained at the feedlot. On d 0, DMI of the 48-h group was lower (P < .05) than that of the 0-h group; DMI of the 72-h group was intermediate. On d 0, the 0-h treatment group had a greater ruminal DM percentage than the 48- and 72-h treatment groups (P < .05); however, due to large within-treatment variation the total weight of ruminal contents did not differ (P > .10) among treatments. There were no decreases (P > .10) in cellulolytic or total bacterial concentration or in the ruminal numbers of cellulolytic or total bacteria due to length of feed and water deprivation on d 0 in either Exp. 1 or 2. In both trials, 48 and 72 h of feed and water deprivation decreased (P < .05) protozoal numbers on d 0 and 4 compared with the 0-h treatment group.
authors.affiliation: Department of Animal Science, Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691, USA.
authors.forename: F L
authors.initials: FL
authors.lastname: Fluharty
authors.forename: S C
authors.initials: SC
authors.lastname: Loerch
authors.forename: B A
authors.initials: BA
authors.lastname: Dehority
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D002417:Cattle / Q000382:microbiology / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D005508:Food Deprivation / Q000502:physiology*; D008297:Male; D011897:Random Allocation; D012417:Rumen / Q000382:microbiology* / Q000502:physiology*; D013997:Time Factors; D014868:Water Deprivation / Q000502:physiology*; D014886:Weaning; D003313:Zea mays / Q000592:standards