Farmer and Veterinary Practices and Opinions Related to Fertility Testing and Pregnancy Diagnosis of UK Dairy Cows

Design of a handheld and portable fluorescence imaging system for quantitative detection of pregnancy-specific biomarkers in cattle

Reproductive management significantly impacts dairy farm productivity, necessitating accurate timely pregnancy detection in cattle. This paper presents a novel handheld and portable fluorescence imaging system designed for quantitative assessment of pregnancy-specific biomarkers, addressing the limitations of current detection methods. The objective was to develop a cost-effective, at-farm solution for detecting pregnancy-specific protein B (PSPB) in bovine plasma samples. The system integrates an imaging module and a custom software application, enabling image capture, data processing, and PSPB concentration determination. Calibration utilizing known PSPB concentrations achieved a 0.6 ng/mL limit of detection. Validation encompassed a comparison with a standard ELISA method using 100 bovine plasma samples; minimal bias and good agreement were observed within the linear range of the calibration curve for both methods. The system offers portability, user-friendliness, and potential for multiplex detection, promising real-time, at-farm reproductive management. This study demonstrates the successful development and validation of a portable fluorescence imaging system, offering an efficient and accurate approach to detecting pregnancy-specific biomarkers in cattle. Its implications extend to improving dairy farm productivity by enabling timely and reliable reproductive management practices.

Validation of Selected MicroRNA Transcriptome Data in the Bovine Corpus Luteum during Early Pregnancy by RT-qPCR

In cattle, the corpus luteum (CL) is pivotal in maintaining early pregnancy by secreting progesterone. To establish pregnancy, the conceptus produces interferon-τ, preventing luteolysis and initiating the transformation of the CL spurium into a CL verum. Although this transformation is tightly regulated, limited data are available on the expression of microRNAs (miRNAs) during and after this process. To address this gap, we re-analyzed previously published RNA-Seq data of CL from pregnant cows and regressed CL from non-pregnant cows. This analysis identified 44 differentially expressed miRNAs. From this pool, three miRNAs-bta-miR-222-3p, bta-miR-29c, and bta-miR-2411-3p-were randomly selected for relative quantification. Using bovine ovaries (n = 14) obtained from an abattoir, total RNA (including miRNAs) was extracted and converted to cDNA for RT-qPCR. The results revealed that bta-miR-222-3p was downregulated (p = 0.016) in pregnant females compared to non-pregnant cows with regressed CL. However, no differences in miRNA expression were observed between CL of pregnant and non-pregnant cows for bta-miR-29c (p > 0.32) or bta-miR-2411-3p (p > 0.60). In silico prediction approaches indicated that these miRNAs are involved in pathways regulating pregnancy maintenance, such as the VEGF- and FoxO-signaling pathways. Additionally, their biogenesis is regulated by GABPA and E2F4 transcription factors. The validation of selected miRNA expression in the CL during pregnancy by RT-qPCR provides novel insights that could potentially lead to the identification of biomarkers related to CL physiology and pregnancy outcome.

The curative effect of ozonated bidistilled water on Escherichia coli-induced endometritis in rats

BACKGROUND

Endometritis is a prevalent and challenging condition that affects livestock, and its effective treatment is the use of intrauterine antibiotics. Antibiotic use may lead to negative consequences, including residue in tissues and the emergence of antibiotic resistance.

OBJECTIVES

The aim of this study was to assess the therapeutic potential of ozonated bidistilled water in the treatment of Escherichia coli-induced endometritis in rat models, comparing it to conventional antibiotic treatment.

METHODS

A total of 21 female Wistar Albino rats were used for this study. E. coli from the uterus of cows with endometritis at a concentration of 1.0 × 109 cfu/mL inoculated into rat uteruses. After inoculation, it was confirmed macroscopically that experimental endometritis was induced in all individuals. And, the rats with endometritis were randomly divided into three groups treated with intrauterine bidistilled water enriched with ozone, antibiotics and 0.9% NaCl. The uterine tissues were examined histopathologically.

RESULTS

In the semiquantitative analyses, significantly lower histopathological scores were observed for both the bidistilled water enriched with ozone and antibiotic-treated endometritis groups compared to the control group (p < 0.05).

CONCLUSIONS

Ozone-enriched bidistilled water can be used in the treatment of experimentally induced endometritis in rats, and can provide effective microbiological and histopathological improvement. Further studies involving larger populations of different species are needed to determine the medical suitability of this new treatment.

Association between blood miR-26a levels following artificial insemination, and pregnancy outcome in dairy cattle

Early pregnancy diagnosis is key to maximise productivity of dairy herds. We previously showed that an increase in the levels of miR-26 could be detected as soon as day 8 of pregnancy in heifers. The aims of this study were to determine whether 1) plasma miR-26 levels would be distinctly elevated, retrospectively, early after artificial insemination in lactating cows with successful compared to failed pregnancies, 2) the early increase in miRNA levels in cows with successful pregnancy could be accounted for by changes in miRNA expression in white blood cells (WBCs), presumably induced by the effects of embryo-derived interferon tau (IFNt), and 3) plasma miRNA levels may provide a reliable early predictor of pregnancy that could be used at a herd level. Blood samples were taken from a total of 34 dairy cows (lactation number 1 to 4) before (D0) and 9 and 18 days after artificial insemination at oestrus, followed by confirmation of pregnancy status by ultrasound on D32. In addition, WBCs collected from non-pregnant cows (n = 4) were stimulated in vitro with recombinant ovine IFNt (0-100 pg/ml). Levels of miRNAs and ISG15, a known IFNt-induced gene, were quantified by qPCR. Relative to D0, a larger increase in plasma miR-26a (P = 0.04) occurred on D9 in cows later confirmed to be pregnant (n = 12) than in cows with a failed pregnancy (n = 22). Expression of miR-26a in WBCs was not affected (P>0.1) by pregnancy status or IFNt stimulation in vitro, in contrast to ISG15 expression which increased markedly (P<0.0001) both in WBC samples collected on D18 from animals later confirmed to be pregnant, and in WBCs after stimulation with IFNt in vitro. Finally, ROC analyses revealed that miR-26a on D9 or D18 could predict pregnancy outcome with much lower accuracy than WBC ISG15 on D18 (Likelihood ratio, 2.3 vs 15.4). In summary, a modest increase in plasma miR-26a levels occurs during early pregnancy in mature dairy cows which may not accounted for by changes in miRNA levels in WBCs or the effects of IFNt. Moreover, compared to ISG15, changes in miR-26a levels may not provide an accurate test for early diagnosis of pregnancy in cows.

Selection of early pregnancy specific proteins and development a rapid immunochromatographic test strip in cows

The most of embryo losses occur before the day 16 after artificial insemination, but there is no low cost and easy operation that can detect pregnancy with high accuracy within three weeks post-insemination in cattle. In this study, blood samples were collected at day 18 of the estrous cycle, and days 18, 25 and 35 of pregnancy, and relative levels of interferon stimulated genes (ISGs), Toll-like receptor (TLRs), complement components, early pregnancy factor (EPF) and pregnancy-associated plasma protein A (PAPPA) proteins were analyzed through Western blot. In addition, a colloidal gold immunochromatographic test strip was developed using the selected antibody, and the test was used for early pregnancy diagnosis. The results showed that there were changes in relative levels of plasma ISGs, TLRs, complement components, EPF and PAPPA proteins during early pregnancy in cattle, and complement component 1q (C1q) could be used as an ideal marker to develop a colloidal gold immunochromatographic test strip for early pregnancy diagnosis. In addition, the accuracy of pregnancy diagnosis by this test strip was 91.67% (11/12) for pregnant cows and 80% (8/10) nonpregnant cows at day 18 after insemination. In conclusion, the changes in plasma ISGs, TLRs, complement components, EPF and PAPPA proteins may be related to the maternal systemic immune modulation during early pregnancy, and a colloidal gold immunochromatographic test strip was developed for early pregnancy diagnosis using C1q as the ideal marker in cows. However, this colloidal gold immunochromatographic test strip needs further studies to improve the accuracy.

Practical Aspects of Twin Pregnancy Diagnosis in Cattle

Simple Summary

This review summarizes the clinical background, possibilities, and limitations of twin pregnancy diagnosis in cattle, with a special emphasis on pregnancy loss aspects. Due to the fact that reproductive performance is strongly affected by twin pregnancy, clinical veterinarians should become familiar with the correct diagnosis of this phenomenon. Thus, each herd must plan a herd-specific management practice to detect twin pregnancies. A highly accurate diagnostic tool is required to detect such pregnancies, already during the first month of gestation. This commentary review focuses on the diagnostic possibilities and limitations on the field.

Abstract

Twin pregnancies are an economically unwanted phenomenon in dairy cattle, not only because they increase pregnancy losses, but also because antibiotics usage and culling rate of the dam are also dramatically increased due to them, furthermore animal welfare issues are also affected through them. In cattle, under field conditions using an early pregnancy determination tool, the first accurate diagnosis from the pregnancy status is available from around day 28, although further confirmations of pregnancy are required. Twin pregnancy diagnosis is available either by rectal palpation or ultrasonography. The measurement of pregnancy specific proteins are also available to determine gestation, but there is still a long way to go to properly identify twin pregnancies. In this commentary, we compared our own results with the literature data in this field with a special emphasis on the clinical practices.