B-mode and colour Doppler sonographic examination of the milk vein and musculophrenic vein in dry cows and cows with a milk yield of 10 and 20 kg

Ueli Braun,Eva Forster

doi:10.1186/1751-0147-54-15

Abstract

BackgroundThis study investigated the effect of milk yield on blood flow variables in the milk vein and musculophrenic vein in dairy cows.MethodsFive healthy dry cows, five cows with a daily milk yield of 10 kg and five others with a daily milk yield of 20 kg underwent B-mode and colour Doppler sonographic examination. The diameter of the veins, blood flow velocities and blood flow volumes were measured on both sides in standing, non-sedated cows using a 7.5 MHz linear transducer.ResultsLactating cows had significantly higher blood flow velocities in the milk vein than dry cows; the maximum blood flow velocity of dry cows and those with a daily milk yield of 10 and 20 kg were 14.04, 38.77 and 39.49 cm/s, respectively, the minimum velocities were 0.63, 3.02 and 2.64 cm/s, respectively, and the mean maximum velocities were 8.21, 26.67 und 28.22 cm/s, respectively. Cows producing 20 kg of milk a day had a blood flow volume of 3.09 l/min, which was significantly higher than 0.79 l/min recorded in dry cows. Lactating cows had significantly higher mean maximum blood flow velocities in the musculophrenic vein than dry cows. Blood flow variables of both veins did not differ significantly between the left and right side.ConclusionThis study showed that milk yield has a profound effect on blood flow variables in the milk vein and to a lesser extent the musculophrenic vein. This must be taken into consideration in future Doppler sonographic studies of these veins and possibly other vessels. Furthermore, measurements on one side are representative of both sides.

Highlights

This study investigated the effect of milk yield on blood flow variables in the milk vein and musculophrenic vein in dairy cows
The milk vein and musculophrenic vein are amenable to Doppler ultrasonographic examination because of their superficial location, and cows tolerate examination of these veins better than the jugular vein [4]
Lactating cows had a two- to three-fold higher cardiac output than dry cows, and because 20 to 30% of the cardiac output in a lactating cow is directed toward the udder, the changes are more pronounced in the milk vein than in the musculophrenic vein [8]

Summary

Introduction

This study investigated the effect of milk yield on blood flow variables in the milk vein and musculophrenic vein in dairy cows. The milk vein and musculophrenic vein are amenable to Doppler ultrasonographic examination because of their superficial location, and cows tolerate examination of these veins better than the jugular vein [4]. The milk vein drains blood from the udder. It is not known whether Doppler sonographic characteristics of blood flow vary with the amount of milk produced or whether be useful for the interpretation of previously established normal ranges of blood flow variables of the milk vein and musculophrenic vein [1,2,3] in relation to milk yield

Methods

Results

Discussion

Conclusion