The authors investigated mammary blood flow by means of a pulsed wave-Doppler ultrasonographic technique in ewes during different production phases. Three groups (Ga, Gb, and Gc, five animals in each) of Comisana sheep were used in the experiment. Ga sheep were milked twice a day by means of a milking machine; Gb sheep nursed their lambs, and group Gc was made up of dry sheep. Recordings of systolic and diastolic pressure of the left and right lateral mammary veins (SSLMV and DSLMV) and arteries (SSLMA and DSLMA) were carried out by means of a Pulse Doppler system. Recordings for Ga were taken before and after milking in the morning and in the afternoon. In Gb and Gc sheep, recordings were taken only in the morning and in the afternoon. Statistical analysis was carried out of the mean values of the recordings taken as mentioned above and the Student's t-test for paired data was used. A statistically significant difference was found in Ga recordings carried out before and after morning (0.05 < P < 0.001) and afternoon (0.05 < P < 0.01) milking. Ga morning mean flow speeds were between 7.

Circulatory phenomena are complex organic functions that depend on several factors as blood viscosity, vascular walls elasticity, cardiac pump rhythm, discontinuous activity, various resistance to blood flow in tissues and spontaneous or induced vasomotor responses. Doppler ultrasonographic method is a valid tool for performing mammary blood flow recordings. Seven Bruna Italiana cows (average age 5 years) during 3 different period of lactation (40, 100, 210 days after the delivery) and during the dry period (290 days after the delivery) were used for our study. Systolic and diastolic flow speeds recordings of right and left external pudendal arteries (before the cranial and the caudal mammary bifurcation) were carried out on each subjects by means of a Pulsed Doppler System. By appliyng repeated measures ANOVA between the different lactation phases and the dry period systolic and diastolic blood flows both for right and left external pudendal artery showed the same pattern. The systolic speed of right and left external pudendal arteries showed the following statistical significances: systolic speed before milking (F (3,18) =37.