Foaling rate of mares that were rebred after pregnancy loss in Hidaka, Japan

Abstract

The purpose of this study was to evaluate foaling rates of mares that were rebred after the pregnancy loss in same reproductive season and to examine factors influencing them in Hidaka, Japan. The study included 82 Thoroughbred mares that had experienced pregnancy loss. The foaling rate of the mares that were rebred after pregnancy loss was 57.3%. The foaling rate decreased as the period until detection of pregnancy loss increased. Aging and lower body condition score of mares decreased the foaling rate.

Relationship between endogenous plasma adrenocorticotropic hormone concentration and reproductive performance in Thoroughbred broodmares

“…15,17 Therefore, it is recommended to evaluate concentrations according to seasonally adjusted reference ranges so as to optimize diagnosis of PPID. 15 As broodmares age, they have decreased conception and delivery rates, 18,19 but some older Thoroughbred broodmares have highly regarded pedigrees and economic value, and maintaining their fertility is desirable. Some factors contributing to a lower conception rate in older broodmares are age-related physical changes of the uterus and vagina, as well as trauma related to delivery.…”

“…Some factors contributing to a lower conception rate in older broodmares are age‐related physical changes of the uterus and vagina, as well as trauma related to delivery. 18 , 19 The hypothalamic‐pituitary‐adrenal axis also can be compromised by infectious diseases such as endometritis and by endocrine dynamics related to reproduction. 3 , 20 Pituitary pars intermedia dysfunction is an age‐related endocrine abnormality reported to occur in 15% to 30% of horses over the age of 15 years.…”

“…As broodmares age, they have decreased conception and delivery rates, 18,19 but some older Thoroughbred broodmares have highly regarded pedigrees and economic value, and maintaining their fertility is desirable. Some factors contributing to a lower conception rate in older broodmares are age‐related physical changes of the uterus and vagina, as well as trauma related to delivery 18,19 . The hypothalamic‐pituitary‐adrenal axis also can be compromised by infectious diseases such as endometritis and by endocrine dynamics related to reproduction 3,20 .…”