The Use of Supplement Blocks for Sheep Grazing Dry, Annual Pastures in California

Abstract

The objective of this study was to evaluate the use of supplement blocks on body weight change, blood parameters, and lambing performance of ewes grazing dry, annual grasses during the summer prior to and during breeding. Two experiments were conducted in successive years to compare performance of unsupplemented control (C) and supplemented (S) Targhee ewes. In the first season, yearling ewes were used while aged ewes (2 or 4 years) were used during the second season. During the first year (1980), supplemented ewes lost less body weight during the dry grazing season than C ewes. However, no lambing performance difference was found between C and S groups. During the second year (1981), supplemented ewes maintained their body weight over the summer while C ewes lost weight. In addition, lambing performance (multiple births) was higher for S than C ewes. Supplementation of ewes with blocks containing molasses, urea, protein, and minerals required little labor input. However, based on lambing performance, it is unlikely that supplementation would be economically profitable under the range conditions utilized in these trials.