Identifying risk factors for early pregnancy loss in Holstein cows
Ciarletta, Cassandra Dominique, author
Pinedo, Pablo, advisor
Engle, Terry, committee member
Applegate, Tanya, committee member
Adequate reproductive performance is a key factor in the success of dairy production. However, events such as early pregnancy loss occur in 15 to 17% of dairy pregnancies and result in diminished fertility and increased culling within herds. Identifying risk factors for pregnancy loss will help farmers use evidence to formulate effective breeding and management protocols to maximize efficiency and welfare. This thesis is focused on identifying risk factors in early pregnancy and explaining the impacts that factors such as body condition and health status pose on the maintenance of pregnancy.Chapter 1 presented relevant literature involving the transition period, reproductive advancements, and reproductive challenges within the dairy industry. The objective of chapter 2 was to characterize the associations between body condition score (BCS) and BCS change, utilizing an automated camera system during early lactation and close to artificial insemination, and pregnancy loss. A secondary objective was to identify the impact of disease on pregnancy loss over multiple periods throughout lactation. Overall, the dynamics of BCS differed between animals that lost pregnancy and those that maintained pregnancy. During the period close to artificial insemination, low BCS, and a significant loss in BCS, as well as disease resulted in higher rates of pregnancy loss.
Includes bibliographical references.