Ultrasonograms of Lactating Mammary Glands

The use of ultrasound for locating and identifying structures in the lactating mammary gland was explored. A method was outlined for using ultrasound. Internal mammary gland measurements were taken at two different locations; i.e., Spots 1 and 2 being one-third and two-thirds the distance from the floor to the top of the udder, respectively. Change in quarter width as well as median width and gap were compared under five stimulative states—i.e., prestimulation; post-stimulation, premilking; post-normal milking; post-oxytocin injection, precomplementary milking; and post-complementary milking. Sonograms were presented which identified the skin, median and lateral suspensory ligaments, milk ducts, and supramammary lymph nodes. Some general observations were reported on the relation among quarter width, intramammary pressure, and quarter milk production, using limited data. It was shown that following a complete milking, the milk ducts are probably collapsed. The feasibility of using ultrasound to visualize internal structures and measure their responses to vary physiological conditions was demonstrated.