Theses and Dissertations Collection

Cattle in the Pacific Northwest graze a variety of forages which vary in quality. The effects of forage quality on heifer reproductive development and fertility is still under investigation. Therefore, the first objective was to investigate the effects of grazing different quality forages preweaning and postweaning on reproductive traits and feed efficiency in heifers. Although nutritional differences were present, pre- and postweaning treatments did not affect reproduction. This indicates different qualities of forage present in Idaho may be utilized for heifers. Feed costs represent a large portion of cattle producers’ expenses. Selecting for feed efficiency allows producers to capitalize on these expenses. However, the effects of selecting for efficiency on reproduction is still undetermined. The second objective was to study the relationship between feed efficiency and reproductive development and fertility. No differences in reproductive traits were detected among heifers ranked as efficient, average or inefficient at utilizing feed for growth.