Use of pregnancy specific proteins and progesterone assays to monitor pregnancy and determine the timing, frequencies and sources of embryonic mortality in ruminants.

Profiles of pregnancy specific proteins in relation to pregnancy status (pregnancy, early or late embryonic mortality, later abortions) have been described in several ruminant species. In field studies, the use of pregnancy specific proteins in combination with P4 measurements is useful to identify the factors (environmental/genetic) influencing specifically the frequencies of early and/or late embryonic mortality. This is illustrated from field studies performed in temperate and sub-tropical environments in high producing dairy cows. Such studies may help to define practical measures to suppress or lower the negative effects of risks factors on fertility.