Authors: DAMJAN GRACNER, GERARD GILLIGAN, NICKHOLAS GARVEY, LUIS MOREIRA, PATRICIA HARVEY, AMANDA TIERNEY, ROBERT ZOBEL
Abstract: It is known that milk production is directly correlated with the blood flow through the mammary gland, and milk veins drain approximately 90% of the total blood passing through this organ. The aim of the present study was to determine the relationship between milk vein internal diameter surface and milk production in Simmental cows. The milk vein internal diameter was measured by ultrasonography in heifers during the 2nd month of the first gravidity, and again on day 50 following the second calving. After the application of exclusion criteria, the internal vein diameter surface area was mathematically calculated (mm2) for a total of 80 cows. No significant correlation between milk vein internal diameter surface in heifers and milk production for the same animal during the second lactation was recorded. However, greater milk vein internal diameter surface 50 days following the second calving was correlated with higher milk production during the second lactation (P < 0.05). These findings suggest that ultrasonography is a useful tool in calculating the milk vein internal diameter surface as an indicator of possible milk production in Simmental cows.
Keywords: Cow, ultrasonography, milk vein, milk production
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