Protracted induction of parturition enhances placental maturation, but does not influence incidence of placental retention in cows

Additional intracervical prostaglandin reduces induction to calving time in buffaloes affected with incomplete cervical dilatation post-uterine detorsion

Conventional induction protocol (CIP) of calving in buffaloes employs the intramuscular (IM) administration of dexamethasone (40 mg) and cloprostenol sodium (500 μg). If there is no progression in terms of cervical dilatation, then a second dose of cloprostenol sodium (500 μg) is administered intramuscularly. This protocol possesses certain demerits: (1) a wide range of response time intervals, and (2) increased risk of fetal membrane retention. Considering the cervix as a caudal continuation of the myometrium with its own contractile potential, and the limitations of CIP, we developed intracervical (IC) drug administration route in buffaloes. The proposed technique was evaluated for its use in a total of 22 cases of incomplete cervical dilatation in uterine torsion-affected buffaloes (IC-14 and IM-8). In addition to CIP, the IC group received an intracervical injection of cloprostenol sodium (500 μg) at the start of the experiment whereas the IM group received an extra intramuscular dose of cloprostenol sodium (500 μg) either after 24 h or when no progression in cervical dilatation is noticed. Surprisingly, the average response time during the experiment in the IC group was 5.8 h shorter (p < 0.000) than in the IM group (IC-5.7 ± 0.17 h vs. IM-11.9 ± 0.74 h). The duration from calving to fetal membrane expulsion (IC-12.8 ± 0.60 h vs. IM-17.5 ± 1.40 h; p < 0.002) and incidence of retention of fetal membrane were also less in the IC group (57.1% vs. 87.5%). The proposed intracervical drug administration potentiates cervical dilatation and can be regarded as a safe, effective, and feasible technique for attaining reliable results.

Impaired placentomal interferon signaling as the possible cause of retained fetal membrane in parturition-induced cows

Although hormonal induction of parturition in cattle results in the successful delivery of healthy calves, the risk of retained fetal membrane is significantly increased. In a previous study, a combination of the long-acting glucocorticoid, triamcinolone acetonide, with a high dose of betamethasone partially normalized the placentomal gene expression during parturition; however, the incidence of retained fetal membrane remained high. This study further explored placentomal dysfunction and aimed to elucidate the mechanism of retained fetal membrane in parturition-induced cows. In this study, transcriptome analysis revealed that enhanced glucocorticoid exposure normalized the expression of a substantial fraction of genes in the cotyledons. In contrast, a significant reduction in the multiple signaling pathway activities, including interferon signaling, was found in the caruncles during induced parturition. Real-time PCR showed that the expression of interferon-tau in the caruncles, but not interferon-alpha or interferon-gamma, was significantly lower in induced parturition than spontaneous parturition. Interferon-stimulated gene expression was also significantly decreased in the caruncles during induced parturition. These results indicate that interferon signaling could be important for immunological control in placentomes during parturition. Additionally, this suggests that interferon-tau might be a pivotal ligand for interferon receptors in the caruncles. This study revealed that peripheral blood leukocytes in prepartum cows transcribed interferon-tau. Macrophage infiltration in the placentome is known to participate in the detachment of the fetal membrane from the caruncle. Thus, this study raised the possibility that immune cells migrating into the caruncles at parturition may act as a source of ligands that activate interferon signaling.

Enhanced glucocorticoid exposure facilitates the expression of genes involved in prostaglandin and estrogen syntheses in bovine placentomes at induced parturition

The mechanism by which the fetal membrane detaches after parturition in cattle is poorly understood, but the upregulation of placentomal prostaglandin and estrogen synthesis are considered to be important. This study investigated whether enhanced glucocorticoid exposure affected the functional maturation of placentomes at induced parturition. Placentomes were collected immediately after spontaneous (beef; n = 5, dairy; n = 5) or induced parturition in beef and dairy cattle. Parturition was induced conventionally using prostaglandin F2α (beef; n = 7, dairy; n = 6) or dexamethasone (beef; n = 6) or with a combination of triamcinolone acetonide (a long-acting glucocorticoid) and a high dose of betamethasone (TABET treatment, beef; n = 6, dairy; n = 9). Gene expression levels and protein localization in placentomes were analyzed by RT-qPCR and immunohistochemistry, respectively. Compared with the conventional methods, TABET treatment resulted in upregulated PTGS2 expression in cotyledons. The expression levels of PTGS2 and PGES were positively correlated in both cotyledons and caruncles. TABET treatment also upregulated the expression of CYP17A1, but not of CYP19A1, in cotyledons. The results revealed, for the first time, that PLA2G4A was localized in microvascular endothelial cells in the cotyledonary villi and the maternal septum. PTGS2 and PGES were colocalized in mononucleated cells of the cotyledonary villi and caruncle epithelial cells adjacent to the chorionic plate. TABET treatment upregulated the expression of placentomal genes involved in PGE2 synthesis and the conversion of pregnenolone to androstenedione. Thus, enhanced glucocorticoid exposure might partially facilitate the functional maturation of placentomes at induced parturition in cattle.

Untersuchungen zur Schwefelversorgung von Milchkühen in Deutschland

Gegenstand: Schwefelüber- und -unterversorgung kann bei Nutztieren zu Leistungsminderung und Erkrankungen führen. Über die Dia - gnostik der Schwefelversorgung in Milchviehherden ist allerdings wenig bekannt. Ziele der Studie waren, die alimentäre Schwefelversorgung deutscher Milchviehherden darzustellen, den Zusammenhang zwischen der Schwefelversorgung und Gesundheit und Leistung zu beurteilen, geeignete Probenmedien für die klinisch-chemische Labordia - gnostik zu bestimmen und Referenzwerte zur Beurteilung der Schwe - felversorgung in verschiedenen Untersuchungsmedien vorzuschlagen. Material und Methoden: Zwischen 2006 und 2014 wurden 569 Milchviehbetriebe beprobt. Von je 10 Tieren der Gruppen –3 bis 0, 0–1, 3–5 und 15–18 Wochen post partum (p. p.) (Betriebe > 200 Tiere) bzw. –3 bis 0, 0–5 und 6–20 Wochen p. p. (Betriebe ≤ 200 Tiere) wurden Blut-, Harn- und Haarproben gewonnen. Gepoolte Vollblut-, Serum-, Plasma-, Harn- und Haarproben (n = 5663) wurden mittels ICP-OESMethode analysiert. Die Schwefelkonzentration der Totalen Mischra - tion (TMR) der Vorbereiter (–3 bis 0 Wochen ante partum) wurden in einem zertifizierten Futtermittellabor bestimmt (n = 625). Ergebnisse: Die mediane Schwefelkonzentration in den Futterrationen betrug 2,3 g/kg TM. Schwefelunterversorgung (< 1,6 g/kg TM; 31% der Betriebe) und -überversorgung (> 4,0 g/kg TM; 11% der Betriebe) in den Futterrationen traten regelmäßig auf. Schwefelunterversorgung war mit verringerter Milchleistung (p < 0,001), Retentio secundinarum (OR = 1,74; p = 0,037), Gebärparese (OR = 2,68; p < 0,001) und Stillbrunst (OR = 2,56; p = 0,014) assoziiert. Positive Korrelationen fanden sich zwischen der Schwefelkonzentration in der TMR und den Schwefelkonzentrationen in Harn (r = 0,50), Serum (r = 0,17), Plasma (r = 0,18) und Vollblut (r = 0,16). Schlussfolgerung und klinische Relevanz: Die Diagnostik der Schwefelversorgung ist für praktische Tierärzte relevant und kann mittels TMR-Analyse und klinisch-chemischer Laborparameter erfolgen. Harn ist dabei als kurzfristiger, Serum, Plasma und Vollblut als mittelfristige und Haar als langfristiger Parameter für die Einschätzung der Schwefelversorgung zu werten.

[Peripheral limb pareses in cattle. Part 2: Diagnostics, prognosis and therapy]

This two-part review presents an overview of peripheral-limb pareses in cattle, which represent the most frequent bovine neurologic disorder and are mostly caused by trauma of specific peripheral nerves. Occurrence, etiology, diagnosis, prognosis and therapy are presented. The second part of the review describes neuroanatomical details important for diagnostics, localization of the neuronal lesion within the lower motor neuron and classification of the grade of peripheral-nerve injury. Furthermore additional diagnostic tools are presented and prognosis, therapy and prevention of peripheral limb pareses in cattle are discussed.

Influence of the duration of calving and obstetric assistance on the placental retention index in Holstein dairy cows

The aim of this study is to evaluate the influence of duration of calving and obstetric assistance on retained placenta incidence of high milk production Holstein cows. Experimental groups were determined according to the duration of the expulsive phase of calving: 2 h (n = 16), 2-4 h (n = 16) and >4 h (n = 12), and additionally allocated in two sub-groups: spontaneous calving (n = 22) and intervention calving (n = 22). Diagnosis of retained placenta was considered with a threshold of 8 h after the expulsive phase. Cows without obstetric intervention, with labor duration of 2 h, presented reduced time needed for placental release, in comparison to those with obstetric assistance. In the 2-4 h group and >4 h, there was no statistical difference. The 2 h and 2-4 h groups with intervention and the spontaneous >4 h group were considered retained placenta groups. On the other hand, performing obstetric intervention when calving period was superior to 4 h nulled the occurrence of retention of fetal membranes. As a conclusion, obstetric assistance predisposes placental retention to calving with <2 h of duration in dairy cows. Conversely, when calving is more than 4 h, performing fetal extraction has a beneficial influence on preventing retained placenta.

The bovine placenta in vivo and in vitro

The gross anatomic features (cotyledonary type) and histologic classification (synepitheliochorial) of the bovine placenta have been known for many years. Thorough ultrastructural analysis as well as a variety of descriptive studies dealing with the localization of cytoskeletal filaments, extracellular matrix, growth factor systems, steroid hormone receptors, and major histocompatibility complex have contributed further significant knowledge. However, this knowledge was not sufficient to solve clinical placenta-based problems, such as retained fetal membranes. Owing to the complexity of the fetomaternal interface in vitro, culture systems have been developed. As trophoblast giant cells (TGC) are thought to be key players in the cattle placenta, most cell culture models attempt to overcome the pitfall of losing the entire TGC population in vitro. Nevertheless, distinct cell line-based in vitro systems such as cell monolayers or 3-dimensional (co-culture) spheroids were generated for the fetal (trophoblast) and maternal (uterine epithelium) placental compartments. Monolayers have been used to study for example, growth factor or hormonal signaling and TGC formation, whereas spheroids served as models for, for example, trophoblast attachment, uterine epithelium depolarization, and also TGC formation. In the future, the use of more improved culture models might lead to better treatments of retained fetal membranes and increased prevention of embryonic loss. In addition, the in vitro models could shed more light on the mechanisms of the differentiation of uninucleate trophoblast into TGC.

Localization of TGF-β and TGF-β receptor in bovine term placentome and expression differences between spontaneous and induced parturition

INTRODUCTION

Mechanisms of detachment of fetal membrane after parturition in cattle are poorly understood. Glucocorticoids trigger the initiation of parturition and may facilitate the placental maturation. We compared the disappearance of trophoblast binucleate cells (BNCs) and expression of transforming growth factor-β (TGFB) in term placentomes between spontaneous and induced parturition to investigate the influences of glucocorticoids on the placental maturity.

METHODS

Cows were delivered spontaneously (SP group) or after the administration of prostaglandin (PG) F(2)α (PG group); dexamethasone, PGF(2)α, and estriol (DEX group); and triamcinolone acetonide, PGF(2)α, and betamethasone (BET group) and placentomes were collected immediately after parturition. The number of BNCs in hematoxylin and eosin stained section was examined. Protein localization and mRNA levels of TGFB and its receptor (TGFBR) were analyzed using immunohistochemistry and qRT-PCR, respectively.

RESULTS

TGFB1 is characteristically localized in the maternal septum in caruncle in contrast to TGFB2 and TGFB3, which are mainly found in cotyledonary villi and maternal epithelial cells. TGFBR1 and TGFBR2 colocalized in BNCs. The number of BNCs was lower in the SP group than in PG and DEX groups. mRNA levels of TGFB1, TGFBR1 and TGFBR2 in the SP group differed from PG and DEX groups. There was no difference between SP and BET groups in all analyses.

DISCUSSION

These results indicate that parturition inductions using PGF(2)α or dexamethasone were not able to induce disappearance of BNCs and change of TGFB signaling. Results in the BET group suggest that investigation into types, dose, and dosage schedule of glucocorticoids may facilitate placental maturation.

Management of Pregnant Heifers in the Feedlot

Pregnant heifers in the feedlot pose many economic and management issues to the producer. Heifers that enter the feedlot pregnant will have increased costs associated with them regardless of the management strategy implemented. It is imperative that practitioners be aware of management concerns associated with pregnant heifers in order to provide sound recommendations for their clients. The purpose of this article is to provide the bovine practitioner with a summary of current literature and present common options for managing pregnant heifers in a feedlot setting.