Metabolic and energy status during the dry period is crucial for the resumption of ovarian activity postpartum in dairy cows

Abstract

It is well known that the degree of negative energy balance in high-producing dairy cows is the major cause of delayed resumption of the ovarian cyclicity that closely relates to fertility. Recent evidence suggests that the energetic situation during early lactation critically affects nutrient partitioning, metabolism, and the reproductive axis, whereas the effect of energy status during the dry period is widely unknown. The aim of the present study was to investigate the effect of energy status throughout the entire dry period until early lactation on the onset of the ovarian cyclicity. Blood samples were taken in 23 cows from dry off at 8 wk before expected parturition to 8 wk postpartum for the analyses of metabolites and hormones, and milk samples were obtained 3 times weekly from d 7 of lactation onward to confirm luteal activity and pregnancy by milk progesterone analysis. Energy balance (EB) was measured weekly during the last 6 wk of the dry period and every other week after parturition. Liver biopsies were obtained at 8 wk before expected calving, within 1 d after calving, and at 4 wk postpartum to measure the mRNA abundance of various gluconeogenic enzymes and metabolic hormone receptors. Cows showing luteal activity within 3 wk postpartum were defined as ovulatory during the first follicular wave postpartum (OC), whereas cows without luteal activity within 3 wk postpartum were defined as anovulatory (AC). Energy balance and, concomitantly, plasma concentrations of glucose, insulin, insulin-like growth factor-1, 3,5,3'-triiodothyronine, and thyroxine were higher in OC than in AC during the dry period. Plasma thyroxine concentrations and body condition score during the postpartum period were higher in OC than in AC. At the mRNA level (19 cows), hepatic insulin receptor decreased from dry off to early lactation, and mRNA of pyruvate carboxylase was highest at parturition and decreased in early lactation in AC only, whereas both parameters remained unchanged in OC. The mRNA abundance of phosphoenolpyruvate carboxykinase-mitochondrial increased from dry off to parturition in both groups, remained high in OC, and decreased again in early lactation in AC. However, none of the investigated gene transcripts differed between OC and AC cows. Thus, ovarian function postpartum appears to be crucially influenced by the energy status during the dry period, which is reflected by timely changes in hepatic mRNA abundance of only a few key metabolic factors in the liver.

Relationship between serum metabolites, body condition, peri- and postpartum health and resumption of postpartum cyclicity in dairy cows

“…This differs from previous studies that report higher serum BHBA concentration at 6 weeks postpartum (Kafi and Mirzael, 2010) and 3 and 5 weeks postpartum (Reist et al, 2000) in cows with delayed RPC. However, other studies have found no relationship between BHBA concentrations during the pre-and postpartum periods and RPC (Castro et al, 2012;Patton et al, 2007).…”

Endocrine and metabolic mechanisms linking postpartum glucose with early embryonic and foetal development in dairy cows

“…Most of the available data indicate that the metabolic profile of prepartum cows is equally important to that of postpartum cows for subsequent uterine health and (or) the establishment of pregnancy (Castro et al, 2012). In their work in which an index for physiological imbalance was created, Moyes et al (2013) concluded that an index that included NEFA, BHBA and glucose was predictive of postpartum uterine disease especially when the prepartum index was used.…”

Relationship between the pre- and postpartum body condition scores and periparturient indices and fertility in high-yielding dairy cows

“…60-70 d after calving). The primary cause of the delay in the return to ovarian activity is connected with the negative energy balance in the periparturient period (8), while the main method applied worldwide to assess the energy status of high-producing dairy cows is the body condition score (BCS). Indication of optimal body condition values at critical times of the production cycle (the dry period, calving day, onset of early lactation) seems to be crucial for a more precise management of dairy cattle herds.…”