Measurement of the Mammary Gland Cistern of Dairy Ewes

Abstract

At the 3rd and 5th month of lactation, using the ALOKA‑250 ultrasonograph with a 3.5 MHz probe, the udder cistern size of the breed Improved Valachian (IV) and the crossbreed IV x Lacaune (IV x LC) was surveyed. Using the method from side 72 ewes were measured, in which the probe was placed in the inguinal‑abdominal fold. Variance analysis was used to evaluate the obtained data (length, width and udder cistern area), taking into account the effect of the genotype, stage of lactation and lactation order. The average length, width and area of the left udder cistern (LUC) was 80.72 mm; 33.53 mm and 1907 mm2; for the right udder cistern (RUC) 79.44 mm; 33.01 mm and 1851 mm2. The genotype had a statistically significant effect on the LUC as well as the RUC size (P < 0.05 to 0.001). The LUC area of the IV x LC ewes was 32.7% bigger than at IV (2175 mm2 and 1639 mm2, respectively), and the difference of the RUC was up to 51% in favour of the crossbreed (2227 mm2 and 1475 mm2, respectively). This may be due to laterality, the natural asymmetry found in many mammals. The variability in the observed variables of the left and right udder cisterns was greater in crossbreeds than in the purebred IV ewes.