Recent developments in the diagnosis and therapy of repeat breeding cows and buffaloes.

Abstract

Repeat breeding (RB) continues to be a big problem for breeders and veterinary clinicians. A brief mention is made of the common aetiological and risk factors for RB in cattle and buffaloes, and the possible diagnostic and therapeutic approaches are described in detail. Important diagnostic tools could include rectogenital palpation, vaginoscopy, uterine cytology and the in vivo imaging technique of ultrasonography. When considering the most common causes of RB, vaginoscopy and palpation continue to be the only diagnostic tools available to clinicians at many locations, while by using ultrasonography, diagnostic accuracy can be increased markedly, especially when dealing with individual cows or buffaloes. Contrarily, when dealing with herds, metabolic profiles and sampling to detect infectious disease must be the clinicians' choice. Of pertinent consideration are the management regimens and feeding practices. Despite the development of many diagnostic procedures such as hormone assays, colour Doppler sonography, and hysteroscopy, diagnosing the cause of pregnancy failure in an individual cow/buffalo continues to be difficult, as a proportion of animals demonstrate obscure infertility. The choice of a therapeutic regimen depends on the possible cause of RB. Recent advances in the therapy of endometritis include the use of immunomodulators such as Escherichia coli lipopolysaccharide, use of eicosanoid PGF₂α and therapy with enzymes with or without therapy with antibiotics, the use of which continues to be debatable. The therapy of ovulation induction in various ovulatory disturbances includes regimens utilizing hCG, GnRH, prostaglandins and their combinations. It appears that RB animals with aberrations of oestrus cycle do demonstrate such ovulation asynchronies. Suprabasal progesterone concentration at oestrus is thought to be an important contributor of RB, but remediation of this is largely unknown although reducing stress appears to be a probable method. Luteal insufficiency can be resolved by administration of hCG and GnRH or progestagens. A brief mention is made of ways of improving management and insemination procedures.