Characteristics of abnormal puerperium in dairy cattle and the rationale for common treatments

Abstract

AbstractThe abnormalities of the puerperium can be arbitrarily divided into two broad categories. Those which arise following a difficult calving or retained placenta are referred to as “common”, while abnormalities such as sub- and anoestrus, irregular cycles, cystic follicles, absence of ovarian activity, repeat breeding and increased number of inseminations per pregnancy are described as “special”. Since the “common” abnormalities are well understood, this paper deals in greater detail with the “special” abnormalities of the puerperium. Based on the axiom that many facets of the “special” abnormalities can be caused by dysfunction of the liver (as in the case of fatty liver), information is presented based on experiments conducted with the over-conditioned dairy cow model (AM) which suffers from both a severe negative energy balance (NEB) and fatty liver syndrome during early lactation. This cow model guarantees a severe NEB, with body weight loss and clear changes in the body condition score (BCS), lower milk production, a higher milk fat concentration, temporary decline in blood insulin and glucose concentrations, elevated blood concentrations of non esterified fatty acids (NEFAs) and beta-hydroxybutyrate (BHB) as well as elevated liver concentrations of tri-acyl-glycerol (TAG) during the first weeks post partum. Additionally, this model leads to a higher incidence of metabolic and infectious diseases. Particular attention was paid to LH pulse frequency and to its value in predicting the occurrence of first post partum ovulation would occur, to oestrous behaviour and to oocytes quality. Cows with fatty liver (> 50 mg TAG/g liver tissue) had longer intervals between parturition and 1st ovulation and showed fewer standing heats within the first 100 days post partum, but the proportion of detected heats, compared to endocrinological “heats” was higher in confirmed AM-cows. Moreover, when AM cows come in heat, their heats lasted longer and had a higher pregnancy rate following AI. However, the developmental capacity of oocytes in AM cows, and in particular oocytes that were destined to ovulate between 80 and 120 days pp, was adversely affected. We conclude that the fatty liver condition is a trigger for many problems, including metabolic and infectious diseases, and also of reduced fertility. Prevention of over fatness at calving (BCS>3.5) is the best guarantee for a normal puerperium.