Influence of Frequency of Drinking on Particulate Passage Rate and Dry Matter Disappearance in Grazing Zebu Cattle

Abstract

Three ruminally cannulated zebu steers were used in a water restriction study. Three drinking frequencies were imposed on the steers: watered daily, once in 2 days, and once in 3 days. Particulate rate of passage was estimated by dosing steers with Yb-labeled forage and collecting fecal grab samples for a 5-day period. Steers were grazed from 0700 h to 1800 h, then brought back to drink, and penned overnight. Particulate passage rate decreased (P<0.05) from 3.8 to 2.5 and 2.1 %/h, while total mean retention time increased (P<0.01) from 54.0 to 65.2 and 80.2 h for steers watered once daily, once in 2 days, and once in 3 days, respectively. In situ dry matter disappearance in the rumen was increased (P<0.01) and dry matter intake decreased by one-third to two-thirds (P<0.01) by water restriction.