B-mode and colour Doppler ultrasonography of the milk vein and musculophrenic vein in eight cows during lactation

Colour Doppler study of blood flow in the portal vein in relation to blood flow in the milk vein, milk yield and body condition of dairy cows during dry period and lactation

In dairy cows, the liver supports the increased nutrient demands of the udder for milk production. Blood flow is key for the transport of these nutrients. This study investigated portal vein blood flow volume (PVBFVol) in relation to daily milk yield (DMY), milk vein blood flow volume (MVBFVol) and body condition parameters of high-producing dairy cows, starting from late lactation, throughout dry period, and consecutive early lactation. Seventeen repeated examinations were performed on 19 Holstein cows and 313 measurement days were finally included. Vein morphology and blood flow were examined via B-mode and spectral Doppler (triplex) ultrasonography, respectively. Body condition parameters recorded were body condition score (BCS), backfat thickness (BFT) measurement with ultrasonography, heart girth circumference (HG) and withers height (WH). Longitudinal relationship of PVBFVol with MVBFVol, DMY, BCS, BFT, HG and WH was analyzed with linear mixed models, with random intercept effects, using restricted cubic splines. A significant increase of 8.28% (p < 0.01) in PVBFVol appeared for every 1 L/min increase in MVBFVol in the univariable model. PVBFVol presented a significant negative association with BCS (p < 0.01) and BFT (p = 0.02), while interaction with production stage was significant, too. PVBFVol significantly increased by 0.38% (p = 0.04) for every 1 kg increase in DMY in the multivariable model. In conclusion, the increased PVBFVol during lactation accompanies the escalation in metabolic activity of the liver and the increased blood circulation through the udder, coping with the udder's escalating nutrient demands for milk synthesis.

Udder Ultrasonography of Dairy Cows: Investigating the Relationship between Echotexture, Blood Flow, Somatic Cell Count and Milk Yield during Dry Period and Lactation

Udder health of dairy cows is related to their productivity and welfare. The period from dry-off to calving and early lactation is crucial. Ultrasonography is a useful and practical tool for the examination of the mammary parenchyma and blood flow. This observational study investigated the relationship between udder echotexture features, blood flow volume (BFVol) in the milk vein, milk somatic cell count (SCC) and daily milk yield (DMY) from late lactation, throughout the dry period and consecutive early lactation. Seventeen repeated measurements were performed on twenty-one Holstein cows. The udder parenchyma was examined with B-mode ultrasonography. Udder echotexture was studied using 15 features: Numerical Pixel Value (NPV), Pixel Standard Deviation (PSD), Skewness, Excess, Contrast, Homogeneity, Correlation, Entropy, Run Percentage, Long-Run Emphasis, Grey Value Distribution, Runlength Distribution, Gradient Mean Value, Gradient Variance and Percentage of Non-zero Gradients. Blood flow in the milk vein was examined with spectral Doppler. Linear mixed-effects models were employed to investigate relationships between BFVol, udder echotexture features, SCC and DMY throughout the study period. Our models showed that a 1 kg increase in DMY was associated with a significant increase of 0.25 L/min in the expected BFVol and that a 1,000,000-cells/mL increase in SCC was associated with a significant BFVol decrease of 0.49 L/min, keeping all other variables constant. Multivariable models showed significant associations between DMY and NPV, between PSD and Long-Run Emphasis, and between SCC and NPV, PSD, Gradient Mean Value, Homogeneity, Gradient Variance and Entropy. In conclusion, udder echotexture and BFVol in the milk vein are related to SCC and milk yield. Ultrasonography can be used for the comprehensive assessment of udder health in support of precision dairy farming.

Characterization of the Normal Portal and Hepatic Blood Flow of Adult Holstein-Friesian Cows

Simple summary

Knowledge of physiological portal and hepatic blood flow in cattle is essential for the use of Doppler ultrasound for diagnostic purposes. In this paper, we describe a protocol for the systematic ultrasonography evaluation of the portal and hepatic system in cattle and report the reference values for healthy cows.

Abstract

In the past, hepatic blood flow in cows was invasively characterized to investigate different pathologies and physiological conditions. However, hepatic blood flow can be easily evaluated with transabdominal Doppler ultrasound. Sixteen healthy adult non-lactating, non-pregnant Holstein-Friesian cows were examined using B-mode and Doppler ultrasound between the right flank and 9^th intercostal space to establish the best approach to the different parts of the portal and hepatic vein systems, and determine normal blood flow characteristics. The main portal vein was characterized by a turbulent, high-velocity flow due to the opposing confluence of the splenic and cranial mesenteric veins, while hepatic and caudal vena cava veins have laminar blood flow, in which the phasicity is considered mainly respiratory in origin. Reference values were determined in relation to the anatomical point of observation. In conclusion, transabdominal Doppler ultrasound of the portal system is a simple technique that allows non-invasive characterization of portal and hepatic blood haemodynamics in cows.

B-mode and Doppler ultrasonography of cranial epigastric vein in healthy and diseased cows and buffaloes

The study was aimed to examine the right cranial epigastric vein (CEV) using B-mode and Doppler ultrasonography in clinically healthy non-gravid cows (20) and buffaloes (20); bovines suffering from traumatic reticuloperitonitis (15 cows and 20 buffaloes) and reticulo-diaphragmatic hernia (5 cows and 15 buffaloes). The data was statistically analyzed and compared between and within the groups. The Doppler parameters of cranial epigastric vein in healthy bovines showed a significant species difference. The blood flow velocities, peak systole (PS), end diastole (ED), time average maximum (TA max) and time average mean (TA mean) were significantly higher in cows compared to buffaloes. However, the pulsatility index (PI), the resistive index (RI), vessel diameter and the depth of the vein were significantly higher in buffaloes compared to cows. The highest per cent change in the Doppler parameters of cranial epigastric vein in between the healthy cows and buffaloes were recorded in the PI followed by the RI. A significant decrease in PS, ED, TA max, TA mean and blood volume flow/min was recorded in cows suffering from traumatic reticuloperitonitis (TRP) and reticulo-diaphragmatic hernia (RDH). The reduction was more in cows with RDH compared to TRP. The CEV was significantly more superficial in TRP affected cows. The PI of TRP affected cows and the TA mean of RDH affected cows recorded the highest per cent change compared to healthy cows. In buffaloes, only the PS was significantly increased in TRP affected buffaloes and those suffering from RDH. Significant species-specific differences exist in the blood flow parameters of healthy cows and buffaloes. Doppler blood flow parameters of diseased cows suffering from TRP and RDH was more significantly affected compared to that of buffaloes. The database generated for non-gravid crossbred Indian cows and buffaloes can be used as a reference range for further studies.