Semester
Spring
Date of Graduation
2002
Document Type
Thesis
Degree Type
MS
College
Davis College of Agriculture, Natural Resources and Design
Department
Animal and Nutritional Sciences
Committee Chair
E. Keith Inskeep.
Abstract
Factors affecting pregnancy maintenance between 28 and 67 days of gestation were studied in dairy cows (N = 211). Beginning on day 28 to 37 post breeding, cows were examined by ultrasonography for a viable pregnancy. Pregnant cows were re-examined for pregnancy losses during the late embryonic (≤day 45) and early fetal stages up to day 67. Overall pregnancy loss was 11%, mostly occurring before day 45. Cows with two corpora lutea maintained fewer pregnancies than cows with one corpus luteum. Pregnancy retention was less when concentrations of progesterone were low during days 28 to 37. The embryo apparently died before luteal regression. Pregnancy retention declined as body condition and age of the cow increased. Pregnancy retention between days 28 and 67 of pregnancy was associated with luteal function during d 28 to 37.
Recommended Citation
Starbuck, Melanie J., "Retention of early pregnancy and its relationship to serum progesterone in dairy cattle" (2002). Graduate Theses, Dissertations, and Problem Reports. 1502.
https://researchrepository.wvu.edu/etd/1502