Effect of IGFBP-4 during In Vitro Maturation on Developmental Competence of Bovine Cumulus Oocyte Complexes.

Insulin-like growth factors (IGFs) are essential for oocyte maturation. Their bioavailability is regulated by their respective binding proteins (IGFBPs) and proteases. IGFBP-4 blocks the biological effects of IGFs. High IGFBP-4 expression has been associated with follicle atresia. We hypothesized that IGFBP-4 affects oocyte developmental competence during maturation. Therefore, the aim of this study was to examine the effect of IGFBP-4 on the developmental rate of bovine cumulus-oocyte complexes (COCs) during in vitro embryo production. Abattoir-derived COCs were matured with rbIGFBP-4 (2000, 540, and 54 ng/mL) compared to a control. Cumulus expansion, oocyte maturation, cleavage, blastocyst, and hatching rates were evaluated. Furthermore, blastocyst gene expression of SOCS2, STAT3, SLC2A1, SLCA3, BAX, and POU5F1 transcripts were quantified using RT-qPCR. No statistical differences were detected among the groups for cumulus expansion, maturation, cleavage, blastocyst rates, or all gene transcripts analyzed. However, at day 8 and 9, the number of total hatching and successfully hatched blastocysts was lower in 2000 ng/mL rbIGFBP-4 compared to the control (day 8: total hatching: 17.1 ± 0.21 vs. 31.2 ± 0.11%, p = 0.02 and hatched blastocyst 6.7 ± 0.31 vs. 21.5 ± 0.14%, p = 0.004; day 9 total hatching 36.4 ± 0.18 vs. 57.7 ± 0.10%, p = 0.009 and hatched blastocyst 18.2 ± 0.21 vs. 38.1 ± 0.11%, p = 0.004). We concluded that high concentrations of rbIGFBP-4 might negatively affect the subsequent ability of the embryo to hatch and possibly compromise further elongation.

Uterine Disease in Dairy Cows: A Comprehensive Review Highlighting New Research Areas.

Uterine disease is an intensely studied part of dairy cattle health management as it heavily affects many commercial dairy farms and has serious economic consequences. Forms of the disease, pathophysiology, pathogens involved and the effects of uterine disease on the health and performance of cows have already been well described by various authors. Lately, researchers' attention has shifted towards the healthy microbiome of the uterus and the vagina to put emphasis on prevention rather than treatment. This aligns with the growing demand to reduce the use of antibiotics or-whenever possible-replace them with alternative treatment options in farm animal medicine. This review provides a comprehensive summary of the last 20 years of uterine disease research and highlights promising new areas for future studies.

Comparison between a Calving Predictive System and a Routine Prepartal Examination in German Holstein Heifers and Cows.

The objective was to validate the efficacy of Moocall® comparing it to a routine clinical examination. Altogether 38 Holstein cows were enrolled in this study (Moocall® group: 16 heifers and 8 cows; control group: 9 heifers and 5 cows). Clinical examinations were performed every 6 h over the 7 days period before the predicted calving date. The examined traits were changes in pelvic ligament relaxation, edema of the vulva, teat filling, vaginal secretion, tail tip flexibility, tail raising and behavior. There were no significant differences in Moocall® alerts between heifers and cows. The time lag between the first warning of Moocall® and the onset of labor was 21.2 ± 20.2 h (max: 95.4 h; min: 0.1 h; p = 0.87) for heifers and 29.6 ± 29.6 h (max: 177.8 h; min: 0 h; p = 0.97) for cows. Linear models including Moocall® alerts showed a significantly better fit to the time until calving than models without Moocall® information (without variable selection: p = 0.030, with variable selection: p < 0.01). In the best-fitting model, class 2 alerts (enhanced tail activity over 2 h) contributed with a higher significance (p < 0.01). Vice versa, models including additional traits were outperformed the use of Moocall® alerts alone. In the best fitting model, class 2 alerts (enhanced tail activity during 2 h) contributed with a higher significance (p < 0.01) than any of the best clinical predictive parameters, such as pelvic ligament relaxation (p = 0.01), tail tip flexibility (p = 0.01) or behavior (p = 0.01).

Histological Comparison of Testicular Needle Biopsy and En Bloc Samples in Abattoir Calves.

the aim of this study was to test whether a single testicular needle biopsy could provide histological results comparable to en bloc resection histology and whether one biopsy was sufficient to reflect the histology of an entire pair of testicles. Two methods of sample collection were tested on 32 bull calves aged five to eight months to compare histological parameters of needle biopsy with those of en bloc resection samples. One testicular needle biopsy of the right and three en bloc samples of both testicles were collected and compared for the number of tubular cross sections, tubules with elongated spermatids (ES), outer/inner diameter of tubules, thickness of tubular wall, and number of Sertoli cells (SC). Additionally, animal data were considered. No significant differences were found between the left and right testis or among the individual locations of en bloc samples. However, histologically significant differences (Bonferroni-adjusted significance level: p < 0.05/6 = 0.0083) were found between the needle biopsy and en bloc resection regarding the tubular cross sections per visual field (p < 0.05), the outer (p = 0.01) and inner diameter and the thickness of the tubular wall (both p < 0.01). In the SOX9 immunohistochemical staining, no significant differences (p > 0.05) could be observed for SC numbers between needle biopsy and en bloc samples. In conclusion, results of testicular needle biopsy do not have the same validity as the en bloc resection histology. Furthermore, one biopsy is insufficient to reflect the histology of the entire testicular pair.

Properties and antimicrobial susceptibility of Trueperella pyogenes isolated from bovine mastitis in China.

Trueperella (T.) pyogenes is an opportunistic pathogen that causes suppurative diseases in domestic animals. In this work, the properties, pathogenesis and phenotypic diversity of T. pyogenes isolates from bovine mastitis were studied. Both pyolysin (plo) and collagen-binding protein (cbp) virulence factor genes were detected by PCR in all T. pyogenes isolates (n = 50). Using the tissue culture plate method, 90% of T. pyogenes isolates were able to form biofilms. The minimum inhibitory concentrations (MICs) of 13 antimicrobials against T. pyogenes isolates were determined. High susceptibility was observed to rifampin (96%), ampicillin (94%), ciprofloxacin (94%), and penicillin (92%), while low susceptibility was found to trimethoprim-sulphamethoxazole (10%) and bacitracin (2%). The intracellular assay revealed that T. pyogenes isolates had different cytopathogenic effects on cells. The high percentage (28.6%) of T. pyogenes isolates suggests that this bacterium is an important contributor to mastitis. Moreover, the high occurrence of multidrug resistance, biofilm production, intracellular survival, and the temporal dynamics of T. pyogenes interactions are key factors for a better understanding of how immunity acts on infections with these bacteria and how they evade immune surveillance, thus highlighting the need for the prudent use of antimicrobial agents in veterinary medicine.

Comparison of a commercial bovine pregnancy-associated glycoprotein ELISA test and a pregnancy-associated glycoprotein radiomimmunoassay test for early pregnancy diagnosis in dairy cattle.

The present study aimed to compare the accuracy of a commercial PAG-ELISA test (Bovine Preg Test 29) and bovine pregnancy-associated glycoprotein radioimmunoassay (PAG-RIA) for diagnosing pregnancy at Day 28 after insemination in dairy cows. Transrectal ultrasonography (TRUS) was performed in 100 Holstein-Friesian cows at Day 28 after artificial insemination (AI; Day 0) to diagnose pregnancy. After TRUS examination, blood sample was collected from the coccygeal vessels of each cow to measure the concentrations of bPAGs by PAG-RIA test and Bovine Preg Test 29. Milk samples were collected at Days 0, 21 and 28 for measurement of progesterone (P4) by ELISA test. The cows were re-examined by TRUS at Day 42 to confirm the pregnancy diagnoses. The actual gold standard was based on TRUS outcomes at Day 28 that agreed with the outcomes of PAG-RIA test or PAG-ELISA test. If the outcomes of TRUS at Day 28 and PAG-RIA test and PAG-ELISA test did not agree, the gold standard was based on the outcome of TRUS at Day 42. Out of 100 inseminated cows, 41 were confirmed pregnant at Day 28 after AI. Based on the actual gold standard, the sensitivity of TRUS, PAG-ELISA and PAG-RIA tests for diagnosing pregnant cows at Day 28 were 92.7%, 90.2% and 100%, while the specificity of the three tests for diagnosing non-pregnant cows were 91.5%, 98.3% and 94.4%, respectively. The overall accuracy of the three tests were 92%, 95% and 97%, respectively. The degree of agreement (Kappa±S.E.) between PAG-RIA and PAG-ELISA test was 0.90 ±0.04. The degrees of agreement between PAG-RIA and PAG-ELISA and TRUS at Day 28 were 0.80±0.05 and 0.76±0.06, respectively. In conclusion, the commercial PAG-ELISA test is a highly accurate method for diagnosing early pregnancy in dairy cows on Day 28 after AI and may be used as an alternative method to the TRUS and the PAG-RIA test.

Electronic monitoring of rumination activity as an indicator of health status and production traits in high-yielding dairy cows.

In view of the demonstrated relationship between rumination time and health status, the general welfare and metabolic condition of ruminants are often assessed by the examination of rumen function. The main goal of this study was to monitor the daily rumination activity (RA) and its connection with actual liveweight (LW), milk yield (MY) and with two diseases (subclinical hyperketonaemia - SHK, uterine disease - UD) in 96 cows on the basis of a total of 1638 observations in Israel. The studied sample gave a highly significant response, showing that the selected diseases had a diminishing impact on RA and LW and no influence on MY. It can be concluded that the change of RA as determined by electronic monitoring, complemented by the change of LW, is a useful general indicator of health status and subclinical disease before the appearance of clinical signs.

Relationship of progesterone, bovine pregnancy-associated glycoprotein-1 and nitric oxide with late embryonic and early fetal mortalities in dairy cows.

The aim of the present study was to determine the relationship of progesterone (P4), bovine pregnancy-associated glycoprotein-1 (bPAG-1) and nitric oxide (NO) levels with late embryonic (LEM; day 28 to day 42) and early fetal mortalities (EFM; > day 42 to day 56) in dairy cows. Transrectal ultrasonography (6-8 MHz) was performed in 100 Holstein-Friesian cows at days 28, 42 and 56 after artificial insemination (AI; day 0) to diagnose pregnancy and to monitor the fate of the embryo. After ultrasound scanning of each cow, a milk sample was collected for assessment of P4 by an ELISA test and a blood sample was collected for assessment of bPAG-1, by using a double-antibody radioimmunoassay, and serum NO metabolites (nitrate + nitrite). Based on ultrasonographic examinations and bPAG-1-RIA, 41 of 100 inseminated cows were confirmed pregnant at day 28 after AI. Nine cows suffered of LEM, and 6 cows suffered of EFM and the overall pregnancy loss rate was 36.6% (15/41) between days 28 and 56 of pregnancy. By logistic regression analysis, there were no significant relationships between the level of P4 and bPAG-1 at day 28 after AI and the occurrence of LEM and EFM. Also, there were no significant relationships between the levels of P4 and bPAG-1 at day 42 and the occurrence of EFM. On the other hand, a significant relationship (P<0.05) was found between NO level at day 28 and the occurrence of LEM. In conclusion, measurement of the serum NO concentration at day 28 of pregnancy might help to predict the outcome of pregnancy by day 42 in dairy cows but further studies are needed to confirm this.

Control of ovulation after prostaglandin treatment by means of ultrasonography and effect of the time of ovulation on conception rate in dairy cows.

Primiparous and multiparous lactating crossbred dairy cows (after Day 40 postpartum) with a mature corpus luteum (CL) (diameter of ≥ 17 mm determined by ultrasonography) and having a follicle with a diameter of ≥ 10 mm were treated with natural prostaglandin F2α (n = 80). Those from the cows that showed oestrus within 5 days after treatment were inseminated (Group 1: n = 39). Other group of cows showing oestrus without treatment (Group 2: n = 41) were inseminated and served as controls. The ovaries of each cow were scanned by transrectal ultrasonography from the day of detected oestrus (Day -1p.m.) until ovulation, to measure the changes in the areas of the CL and the largest follicle and to determine the occurrence of ovulation. Although no significant differences were found between the treated and untreated cows in terms of a reduction in the area of the corpora lutea and of an increase in the area of the dominant follicles, the mean area of these follicles in Group 2 was somewhat greater than in Group 1. The highest conception rate was achieved if AI was performed at the same day as ovulation occurred in both groups (conception rate in treated group was: 62.5%, in untreated group: 66.6%, respectively) between Day 0a.m. to Day 0p.m.. In Group 1, 54.5% conception rate has been achieved if ovulation occurred between Day 0p.m. to Day 1p.m., or 50% between Day 1p.m. to Day 2p.m. after AI, and 53.3% and 44.4% in Group 2, respectively. The conception rate for cows that ovulated before AI in Group 2 was 25%. No ovulation occurred in 7 cows until Day 2p.m. after AI and none of them became pregnant. The overall conception rate was approximately 50% in both groups, but when the cows had ovulated too early or too late relative to the time of AI, the conception rate was significantly lower, thus determination of the optimal time for AI is of great practical importance in dairy herds.

Evaluation of the on-line electrical conductivity of milk in mastitic dairy cows.

Mastitis is a persistent, inflammatory reaction of the udder tissue, which entails a decline in potassium, and is also responsible for a higher somatic cell count (SCC) and electrical conductivity (EC) of milk. The measurement of EC is an indirect, rapid method to detect subclinical mastitis from milk. The aim of this study was to analyse the EC of milk throughout the lactation, around the day of mastitis detection, and also to estimate its heritability based on data from a large-scale dairy farm. Shortly after calving the EC value generally decreases; however, it was discovered that from the thirteenth week onwards, substantial differences arise between the mastitic and healthy groups of cows. The authors observed a significant (P < 0.001) increase in EC before the detection of clinical mastitis. This higher value (around 11 mS) persisted for 4 days, then it gradually returned to the normal level. The EC of milk from daughters sired by different bulls responded differently in case of mastitis. The heritability of EC seems to be high (h2 = 0.56). Therefore, the EC trait can be a beneficial indicator in detecting mastitis and should be considered in sire selection.

The effect of a single oxytocin or carbetocin treatment on uterine contractility in early postpartum dairy cows.

The uterotonic characteristics and effectiveness of a single treatment with either oxytocin or carbetocin were quantified in early postpartum dairy cows after normal, uncomplicated calvings. Both the short-term (within 4 h), and the long-term effects (between 12 and 36 h) of the two treatments were compared. Between 14 and 16 h after parturition, 27 multiparous Holstein-Friesian dairy cows, without fetal membrane retention, were selected and divided into three groups. The first group (n = 9) was administered 50 IU oxytocin intramuscularly, the second group (n = 10) received 0.35 mg carbetocin, while animals of the third group (n = 8), serving as a control, were administered 5 mL saline solution. A transcervically introduced open tip catheter system was used for the non-invasive acquisition of the intrauterine pressure (IUP) recording. After digitalization, the signals were analyzed, using a specially adapted graphical software program. A significant short-term effect was found both in the oxytocin and carbetocin treated groups from the analysis of the contraction frequencies (FREQ) and of the total area under the curve (TAUC). After significant peaking during the first post-treatment hour, the values of the parameters for these two groups remained higher during the second hour, returning to the initial levels again during the third hour and reaching the level of the control group by the 12th hour. Mean amplitude (AMP), duration (DUR) and area under the curve (AUC) of pressure cycles were not significantly affected by any of the treatments. Although mean FREQ and TAUC significantly declined from the initial values to 12, 24 and 36 h in all groups, mean AMP and AUC in the oxytocin and carbetocin treated groups, and mean DUR only in the carbetocin treated group to 12 and 36 h, the long-term analysis revealed no significant treatment differences for any IUP parameters. Because treatment with either oxytocin, or carbetocin elicited similar uterotonic effects in healthy, early postpartum cows, it cannot be expected, that using carbetocin in preference to oxytocin, will result in a more beneficial clinical effect on uterine involution during this period.

Validation of pressure measurements and electromyographic results for the uterus of cattle during the early postpartum period.

OBJECTIVE: To evaluate methods for on-farm measurements of uterine contractility in postpartum dairy cows by comparing data simultaneously recorded by use of 2 intrauterine pressure (IUP) devices and quantified electromyographic (EMG) signals. ANIMALS: 5 cows during the first 48 hours after parturition. PROCEDURE: 2 EMG electrodes were implanted on the surface of the gravid uterine horn. Parturition was induced by injection of a prostaglandin F2alpha analogue at day 274 of gestation. An open-tip catheter and pressure microtransducer were transcervically inserted and affixed to a caruncle immediately after calving. Changes in IUP were recorded concurrent with EMG recordings during 2-hour periods at 2, 6, 12, 18, 24, 36, and 48 hours after parturition. Novel acquisition and analysis software programs were used with a digital data-filtering capability for evaluation of IUP and EMG signals. RESULTS: The method for intrauterine fixation of the 2 pressure measurement instruments was effective and allowed easy, externally guided removal of the devices 48 hours after parturition. There was a high correlation between the data obtained by the 2 pressure measuring systems. Good correlation was also found between pressure data obtained by the open-tip catheter system and EMG signals. Although the quantified IUP and EMG signals were highly comparable, synchronization was not always evident during visual inspection of these signals. CONCLUSIONS AND CLINICAL RELEVANCE: The open-tip IUP catheter system with a special fixation method is suitable for use in on-farm studies. It will enable investigators to record natural and pharmacologically influenced uterine contractility in early postpartum dairy cows.

Characteristics of bovine early puerperal uterine contractility recorded under farm conditions.

A non-invasive, digital technique was used to measure and quantify intrauterine pressure (IUP) changes in early postpartum dairy cows kept under farm conditions in order to document physiological changes in uterine contractility after uncomplicated calvings. In addition, possible relationships between characteristics of uterine contractility and blood ionized calcium (Ca(2+))-concentrations were investigated. Recordings of uterine contractility were made by using a transcervically inserted open tip catheter in 12 healthy cows during their first 48h after calving. The IUP recording technique appeared easily applicable under farm conditions. Although mean frequency (FREQ), amplitude (AMP) and area under the curve (AUC) of the myometrial contractions significantly decreased due to time, untreated early postpartum cows showed a high variability in characteristics of uterine contractility. There was no correlation between blood Ca2+ -concentrations and any of the contractility parameters.