Efficacy of pregnancy specific protein B assay to predict pregnancy and pregnancy rate in sheep

Most North Dakota sheep production scenarios require substantially more resources, such as feed, labor, and facilities during late gestation and lactation. Early identification of pregnancy and pregnancy rate in sheep provides managers several options to increase flock productivity. First, removal of non-pregnant ewes can increase available resources for pregnant ewes. Second, identification of pregnancy status of ewe lambs (9 months of age) allows producer to market ewe lambs as lamb, instead of waiting until after the lambing season, when ewe lambs will be older than 12 months and are more likely to be classified as mutton. Third, identification of pregnancy rate in sheep allows producer to target feed resources to ewes baring multiple lambs. Twin baring ewes require 30% more feed than singleton baring ewes. Finally, identification of early and late lambing ewes allows producer to target feed resources to ewes during period of greatest need. Late gestation singleton and twin baring ewes require 50 and 80% more feed, respectively, than ewes in early gestation.