Twelve-oxoeicosatetraenoic acid-induced fetal membrane release improves postpartum ovarian function, milk production, and blood plasma biochemical parameters in cows.

OBJECTIVE: We aimed to determine the effects of 12-oxoeicosatetraenoic acid (12-KETE)-induced placenta release on the performance of mother cows (milk yield, ovarian function, and blood plasma biochemical properties). METHODS: Experimental treatments were as follows: i) natural delivery including natural placental release (control cows); ii) induced calf delivery with placental retention (RP cows); and iii) induced calf delivery and 12-KETE-induced placental release (KE cows). Delivery in pregnant KE cows was induced with dexamethasone and prostaglandin. These cows were injected with 12-KETE after calf discharge, resulting in the release of the fetal placenta. RP cows were not treated with 12-KETE after inducing delivery, resulting in placental retention. RESULTS: The milk yield in RP cows during the first 50 days after delivery was significantly lower than that in control cows (p<0.05), whereas KE cows exhibited a similar milk yield to that of control cows. The postpartum plasma progesterone levels of control cows increased 14 days after delivery on average; however, its increase was delayed by 10 days in RP cows. Meanwhile, the 12-KETE treatment (KE cows) brought the timing of progesterone increase forward to the normal level (control cows). Among the 20 biochemical parameters examined, the total cholesterol levels in blood plasma 14 days after delivery were lower in RP cows than that in the other two treatment groups (control cows and KE cows) (p<0.05). In addition, the plasma level of haptoglobin tended to be low in cows that discharged their placentas shortly after delivery. CONCLUSION: These findings indicate that 12-KETE treatment can alleviate the disorder caused by placental retention.

Prediction of 24-h and 6-h Periods before Calving Using a Multimodal Tail-Attached Device Equipped with a Thermistor and 3-Axis Accelerometer through Supervised Machine Learning.

In this study, we developed calving prediction models for 24-h and 6-h periods before calving using data on physiological (tail skin temperature) and behavioral (activity intensity, lying time, posture change, and tail raising) parameters obtained using a multimodal tail-attached device (tail sensor). The efficiencies of the models were validated under tethering (tie-stall) and untethering (free-stall and individual pen) conditions. Data were collected from 33 and 30 pregnant cattle under tethering and untethering conditions, respectively, from approximately 15 days before the expected calving date. Based on pre-calving changes, 40 features (8 physiological and 32 behavioral) were extracted from the sensor data, and one non-sensor-based feature (days to the expected calving date) was added to develop models using a support vector machine. Cross-validation showed that calving within the next 24 h under tethering and untethering conditions was predicted with a sensitivity of 97% and 93% and precision of 80% and 76%, respectively, while calving within the next 6 h was predicted with a sensitivity of 91% and 90% and precision of 88% and 90%, respectively. Calving prediction models based on the tail sensor data with supervised machine learning have the potential to achieve effective calving prediction, irrespective of the cattle housing conditions.

Improving the accuracy of estimating blood calcium concentration in Holstein cows using electrocardiographic variables.

We previously reported the possibility of using the electrocardiogram variable to estimate blood calcium (Ca) concentration in dairy cows based on the strong positive correlation between the blood Ca concentration and the inverse of the corrected ST peak interval (STc-1). To improve the accuracy of the estimation of blood Ca concentration, we investigated the relationship between blood Ca concentration and STc-1 for each postpartum day and available variables other than STc-1. We measured multiple variables (milk yield, calving number, age, body temperature, etc.), including serum total Ca concentration (tCa), blood ionized Ca concentration (iCa) and STc-1 in 462 Holstein cows on days 0, 1, 2, 3, 5, and 7 postpartum. A very high correlation was observed between iCa and tCa. The association between tCa and STc-1 for each postpartum day had a high coefficient of determination of 0.61-0.79 postpartum 0-2 days but decreased after the third day. In the investigation using the data from postpartum days 0-2, STc-1, heart rate interval, calving number, and age were highly correlated with tCa. In addition, a multiple regression equation was obtained with tCa as the objective variable and STc-1 and calving number as explanatory variables. The estimation accuracy was improved as compared with the simple regression equation using only STc-1 as the explanatory variable. This multiple regression equation was used for 11 cows suspected of having hypocalcemia, and it was able to correctly detect cows requiring early treatment, except for one cow.

Optimization of diagnostic methods and criteria of endometritis for various postpartum days to evaluate infertility in dairy cows.

Postpartum endometritis is the main cause of infertility in dairy cows, but there is a lack of critical diagnostic criteria. We aimed to 1) determine the optimal diagnostic method and criteria of endometritis for various postpartum days to evaluate infertility, and 2) assess the diagnostic accuracy of a combination of diagnostic methods. Holstein dairy cows (n = 441) from nine commercial dairy herds were examined at 42 ±â€¯7 days postpartum by using 5 methods: 1) transrectal palpation measurement of the cervical diameter, 2) ultrasonographic measurement of the fluid in uterus (FIU) score, 3) vaginoscopic detection of external uterine orifice hyperemia, 4) vaginal discharge score (VDS), and 5) endometrial cytological percentage of polymorphonuclear leukocytes (PMN%). The clinical findings that were significant in the Pearson chisquare test and had the highest sum of sensitivity and specificity for infertility at 100, 125, 150, 175, and 200 days after parturition were determined the optimal criteria of endometritis. Logistic regression and the Cox proportional hazards model were used to compare the accuracies of the different diagnostic methods for infertility at various postpartum days. The combinations of methods which were significant in Pearson chisquare test and had the highest sum of sensitivity and specificity for infertility were proposed as the optimal combination for determination of endometritis status for various postpartum day. The optimal diagnostic criteria were PMN% ≥ 6.0, FIU ≥ 2 (continuous hyperechogenic or large amount of storage material), or VDS ≥ 2 (mucopurulent or worse vaginal discharge) for postpartum days 100 and 125; PMN% ≥ 8.0, FIU = 3 (large amount of storage material), VDS ≥ 2, or external uterine orifice hyperemia for day 150; PMN% ≥ 6.0, FIU = 3, VDS ≥ 2, or external uterine orifice hyperemia for day 175; and PMN% ≥ 5.0, FIU = 3, VDS ≥ 2, or external uterine orifice hyperemia for day 200. Only the results of endometrial cytology were related to infertility regardless of the postpartum days to evaluate infertility or statistical models. Compared with the sensitivity and specificity of a single diagnostic method, the sensitivity of a combination of methods improved but specificity decreased. We concluded that different diagnostic methods and criteria were required for postpartum days to evaluate infertility and diagnostic accuracy was improved by a combination of diagnostic methods rather than by a single method.

Brainstem auditory evoked potentials in experimentally-induced bovine spongiform encephalopathy.

This study was carried out to evaluate the features of neurological dysfunction in experimentally-induced bovine spongiform encephalopathy (BSE)-infected cattle using brainstem auditory evoked potentials (BAEP). The progressive prolongation of peak latency of waves III and V was observed right-and-left bilaterally at the onset of neurological symptoms. The peak latency of wave V and the I-V interpeak latency (IPL) in BSE cattle 22 and 24 months after intracerebral inoculation were significantly (P<0.05) prolonged compared with the control cattle. In addition, the amplitude of the BAEP waves of the BSE cattle were low compared with the control cattle. Hearing loss occurred in the BSE cattle that showed advanced neurological symptoms such as tremor. It is thought that this BAEP data reflects a functional disorder in the central auditory nerve pathways characteristic of experimentally-induced BSE.

Brainstem auditory evoked potentials in Japanese Black and Holstein cattle.

This study was performed to examine normal brainstem auditory evoked potential (BAEP) data for adult Japanese Black cattle and to evaluate whether differences exist in the peak latencies, interpeak latencies (IPL) and waveforms of BAEP between Japanese Black and Holstein cattle. The peaks were detected as major waves I, II, III and V in each group. The threshold of the BAEP waves in the Holstein cattle was 65-75 dB nHL, but the threshold in the Japanese Black cattle was 75-85 dB nHL. The I-III and I-V IPLs were significantly shorter in the Japanese Black compared with the Holstein cattle at an intensity of 105 dB nHL. The present findings suggest that the IPL and wave threshold of BAEP are influenced by bovine breed.

Detailed structural examinations of covalently immobilized gold nanoparticles onto hydrogen-terminated silicon surfaces.

The modification of flat semiconductor surfaces with nanoscale materials has been the subject of considerable interest. This paper provides detailed structural examinations of gold nanoparticles covalently immobilized onto hydrogen-terminated silicon surfaces by a convenient thermal hydrosilylation to form Si-C bonds. Gold nanoparticles stabilized by omega-alkene-1-thiols with different alkyl chain lengths (C3, C6, and C11), with average diameters of 2-3 nm and a narrow size distribution were used. The thermal hydrosilylation reactions of these nanoparticles with hydrogen-terminated Si(111) surfaces were carried out in toluene at various conditions under N2. The obtained modified surfaces were observed by high-resolution scanning electron microscopy (HR-SEM). The obtained images indicate considerable changes in morphology with reaction time, reaction temperature, as well as the length of the stabilizing omega-alkene-1-thiol molecules. These surfaces are stable and can be stored under ambient conditions for several weeks without measurable decomposition. It was also found that the aggregation of immobilized particles on a silicon surface occurred at high temperature (> 100 degrees C). Precise XPS measurements of modified surfaces were carried out by using a Au-S ligand-exchange technique. The spectrum clearly showed the existence of Si-C bonds. Cross-sectional HR-TEM images also directly indicate that the particles were covalently attached to the silicon surface through Si-C bonds.

Serum leptin levels during the periparturient period in cows.

Serum leptin concentrations were measured in antenatal and postnatal cows housed at two different locations. The mean serum leptin concentration was 9.2 +/- 0.6 ng/m l (n=22) in one group, and was slightly lower in the other (7.4 +/- 0.4 ng/ml, n=54), probably because of the different nutritional conditions between the two groups. There was no consistent variation in relation to the menstrual cycle and the periparturient period in both groups. Moreover, serum leptin concentrations during the periparturient period were independent of the number of delivery and the incidence of mastitis and milk fever. These results are quite different from those in rodents and human, suggesting the different regulatory mechanism of circulating leptin concentration in cows.