A méhnyomás-mérés jelentősége a közvetlen postpartum időszak élettani folyamataiban szarvasmarhában = The importance of intrauterine pressure measurement in the physiological processes of the early postpartum period in cattle

Míg a méh belső nyomásváltozásainak (IUP) analóg elemző rendszerénél a felvételek minőségének és a szubjektív tényezőknek is jelentős szerep jut, addig az általunk kifejlesztett digitális eljárás jóval pontosabb, standardizálható. Telepi használat esetén is alkalmasnak bizonyult frissen ellett tehenek méhkontrakciójának pontos mérésére. Szabályos involúciójú tehenekben a méhösszehúzódások gyakorisága, erőssége és a görbe alatti területek átlagos nagysága nagy egyedi változatosság mellett legkifejezettebben az ellést követő 12. és 24. óra között csökkent. A vér Ca2+-koncentrációjának enyhe ingadozása nem befolyásolta a méhnyomás-értékek alakulását. A 14-16.óra között alkalmazott egyszeri oxytocin és a karbetocin-kezelés méhkontraktilitást fokozó hatása egészséges tejhasznú tehenekben hasonló volt, hatásukra csak az 1. és 2. órában voltak gyakoribbak a méhösszehúzódások, és nőtt az összesített görbe alatti területek nagysága. A kezelések elhúzódó, késői hatást nem eredményeztek. A szájon át adott CaCl2 gyorsan felszívódott, de enyhe pozitív hatása normokalcémiás tehenek vérében csak rövid ideig, mintegy 60 percig volt mérhető. A hipokalcémiás tehenek méhkontrakcióinak telepi adatfelvételét elvégeztük, az eredmények feldolgozása megkezdődött. A korai puerperiumban történt méréseink azt mutatták, hogy a természetes PGF2a nem fokozza a méh belső nyomását, így valószínűsíthető, hogy a szabályos involúciójú tehenekben nem is javítja a méh kontraktilitását. | While using the analogue analyzing method of intrauterine pressure (IUP), where both recording quality and subjective factors play important roles, our newly developed digital method gave more accurate results and can be standardized. Even under field conditions, it proved to be a proper method for measuring uterine contractility in fresh calved cows. Contraction frequency, intensity and the area under the curve most intensively decreased between 12 and 24 hours after calving in dairy cows with normal involution, however this decline considerably varied among individuals. The slight changes in blood Ca2+ concentration did not influence the changes in IUP values. A single treatment with oxytocin or carbetocin between 14 and 16 hours postpartum induced similar stimulative effects on uterine contractility in healthy cows, by increasing contraction frequency and total area under the curve during the 1st and 2nd hour after treatment. Treatments did not result in any long term effect. Per oral treatment with a CaCl2 paste resulted in a fast absorption, but its slight positive effect lasted for only about 60 min as measured in the blood of normocalcemic cows. The acquisition part of measuring uterine contractility in hypocalcemic cows has been performed, and data analysis has been started. Our measurements during the early puerperium showed that natural PGF2a did not enhance IUP, suggesting that it does not improve uterine contractility in cows with normal involution

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

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

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

Estrus Detection in a Dairy Herd Using an Electronic Nose by Direct Sampling on the Perineal Region

Estrus detection is very important for the profitability of dairy herds. Different automatic systems for estrus detection have been developed over the last decades. Our study aimed to assess the ability of the electronic nose (EN) MENT-EGAS prototype to detect estrus, based on odor release from the perineal headspace in dairy cattle by direct sampling. The study was performed in an Italian dairy farm using 35 multiparous Holstein–Friesian cows. The cows were divided into three groups: group I included 10 lactating 5-month pregnant cows, group II included 19 lactating cycling cows, and group III included 6 cows that were artificially inseminated 18 days before the trial. Odors from the perineal headspace were collected using the MENT-EGAS prototype. In group I, odors were collected once a day for 5 consecutive days. In group II, odors were collected twice daily from day 18 until day 1 of the reproductive cycle. In group III, odors were also collected twice daily from the presumable day 18 of gestation until day 22. Principal component analyses (PCA) of the perineal headspace samples were performed. PCA in group I revealed no significant discrimination. PCA in group II revealed clear discrimination between proestrus and estrus, and between estrus and metestrus but no significant discrimination was obtained between proestrus and metestrus. PCA in group III revealed that in four cows the results were similar to group I and in two cows the results were similar to group II. On day 40 of the presumable pregnancy, the ultrasound examination revealed that only the four cows were pregnant and the other two cows were regularly cycling. On the basis of our findings, we conclude that it is possible to accurately detect estrus in dairy cattle from directly collected odor samples using the MENT-EGAS prototype. This represents the first study of estrus detection using an EN detection by direct sampling. EN technologies, such as MENT-EGAS, could be applied in the future in dairy cattle farms as a precise, non-invasive method for estrus detection

Physiological and clinical aspects of uterine contractility during the postpartum period in cows

The individual studies, presented in separate chapters of this thesis, were designed to get answers to certain methodological problems and biological questions associated with the myometrial function of early postpartum dairy cows. Chapter 1 introduces the topic by briefly summarizing the events occuring in the puerperal uterus, focusing on the role of myometrial contractions, and listing some of the possibilities used to record uterine contractility. The demand for an accurate, non-invasive, intrauterine pressure (IUP) recording and analysis system, for use in postpartum cows kept on dairy farms, is mentioned - as is the need for more physiological data on uterine functioning after normal parturition. Chapter 2 reviews the development of techniques for measuring, analyzing and evaluating uterine activity. Changes in IUP during the normal and abnormal bovine postpartum period are detailed in chronological order. Following their previous introduction, the effects of some drugs, used to influence uterine contractility, are reviewed. Chapter 3 describes the good correlations between the results from two simultaneous electromyographic (EMG) recordings (using surgically imbedded bipolar electrodes), those from two different IUP recording methods (an open tip catheter and a microtransducer system), as well as those from the above IUP and EMG methods, in cows after induced parturition. It outlines a new digital technique for properly characterizing mechanical activity in the early postpartum bovine uterus even under on-farm circumstances, based on low-cost, disposable IUP recording units, which utilize a transcervically introduced, non-invasive method for fixation of the IUP measuring units (the "virtual knot"), and especially developed acquisition and analyzing softwares with a post-measurement filtering capability. Chapter 4 describes the successful application of a digital non-invasive, open tip catheter system to quantifying IUP changes in untreated, healthy, postpartum cows under on-farm conditions. While showing considerable individual variability, the mean frequency (FREQ), amplitude (AMP) and area under the curve (AUC) values for the myometrial contractions decreased continuously and significantly during the first 48 hours postpartum, with the largest decline occurring between 12 and 24 hours. The IUP values showed no significant correlations with blood Ca2+-concentrations. Using the above system, the uterotonic effects of a single intramuscular treatment with oxytocin (50 IU) or carbetocin (0.35 mg), 14 to 16 hours after normal parturition, are examined in Chapter 5. These treatments were similarly effective, almost identical in enhancing uterine contractility. In each case, FREQ and total area under the curve (TAUC) showed a significant short-term treatment effect (until 4 h after treatment) - peaking during the 1st post-treatment hour, and returning to the initial levels during the 3rd hour. Other parameters (AMP, DUR /duration/ and AUC) were not affected. None of the IUP parameters revealed any significant effect in the long-term analysis (12 to 36 hours post-treatment) due to any of these treatments. Chapter 6 details an investigation into oxytocin-induced prostaglandin release - as characterized by plasma 15-ketodihydroprostaglandin-F2α concentrations. Intramuscular treatment with a therapeutical dose of oxytocin (50 IU) between 13 and 15 hours after calving did not significantly alter prostaglandin release. However, administering the oxytocin on two cows intravascularly, did provide evidence of an oxytocin-induced prostaglandin synthesis. It is hypothesized that, although the quantity of released prostaglandins appearing in the peripheral circulation after an intramuscular oxytocin treatment seems to be too small to be detected, it may have an indirect effect through the stimulation of a local prostaglandin synthesis and release, making an additional contribution to the direct uterotonic effect of oxytocin. Chapter 7 summarizes and generally discusses the previous chapters in the context of the most current knowledge available in the literature, listing the main outcomes and conclusions of the thesis

Clinical diagnosis of bovine twin pregnancy - Literature review

SUMMARY Background: The authors overview the relevant literature on clinical diagnostic possibilities of twin pregnancy in cattle. Objectives: The different methods of pregnancy diagnosis were evaluated, underlining the advantages and disadvantages of each method. In practice the pregnancy loss due to embryonic/foetal mortality is the main factor affecting the results of pregnancy diagnoses, therefore the nature of the phenomenon must be taken into consideration when evaluating any method. However, the measurement of pregnancy proteins either in sera or milk is an accurate method for setting up pregnancy diagnosis, at the moment it is not accurate for distinguishing between twin and singleton pregnancies. Diagnosing pregnancy from Days 24-25 by means of ultrasonography is also proper for diagnosing twins, but because of the above-mentioned effect of pregnancy loss, confirming diagnosis is required in cases of twin pregnancies by means of ultrasonography