The Repeat breeder cow

Abstract

Cows that fail to become pregnant after 3 inseminations may be termed repeat breeders (RBs).This paper reviews the incidence, economics, etiology and management of the RB cow. The incidence of RB in U.S. dairy herds is approximately 20% and depends on herd conception rate. Factors resulting in repeat breeding are discussed. Repeat breeders experience increased failure of fertilization due to tubal pathology and suboptimal breeding management. Increased embryonic mortality is evident in RBs before maternal recognition of pregnancy. Uterine environment and uterine asynchrony may play important roles in reducing fertility in RBs. Non-specific uterine infections are not major causes of RB but specific viral and bacterial agents known to cause early embryonic death can play roles. Clinical management of RBs should begin with record analysis and thorough reproductive examination. When no specific pathology is detected, prognosis for fertility is guarded but use of GnRH at time of insemination, synchronization of ovulation or uterine lavage maybe attempted. Invaluable animals, embryo transfer or oocyte aspiration with IVF and IVC has resulted in genetic recovery.