Flushing of Range Ewes by Supplementation, Drylot Feeding, or Grazing of Improved Pasture

Abstract

The lambing performance of range ewes was compared with that of similar ewes which were supplemented for 17 days prior to and the first 17 days of breeding (four years), were fed in drylot (four years), or grazed an improved pasture (two years) over the same period. Supplementation (2.25 kg alfalfa pellets/ewe/week, fed twice weekly) did not improve lambing performance, but drylot feeding (1.82 kg alfalfa hay/ewe/day) increased the number of lambs born/ewe present at lambing from 101 to 128% (P < 0.001). Access to improved pasture also increased lambing percentage (from 110 to 138) (P < 0.01). Current feed costs, and availability and alternative uses of an area of improved pasture will determine which of the two effective treatments is most likely to result in the greatest net returns from flushing. The observed flushing effect was associated mainly with the live-weight change over the flushing period, rather than any static live-weight effect. For every kg increase in the weight gain during flushing, lambing % increased by about 8%.