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This study aimed to examine the ultrasonographic characteristics of the mammary gland in post-partum ewes (1 to 4 weeks after lambing) of varying genotypes for correlations with the chemical composition of milk. Ultrasonograms of mammary glands in coronal (C) and sagittal (S) planes were obtained using 5.0- and 7.5-MHz transducers from four Polish Mountain (PMt) and six Olkuska (Olk) ewes. Computerized image analyses of all images have been performed to determine pixel intensity (numerical pixel values-NPV) and heterogeneity (pixel standard deviation-PSD) of the mammary gland stroma/parenchyma. In PMt ewes examined with the 5.0-MHz probe, the mean NPV-C correlated negatively with C17:0 (margaric acid) and C17:1 c10 (heptadecenoic acid). Furthermore, NPV-S correlated negatively with C17:0 content of milk. In PMt ewes examined with the 7.5-MHz transducer, the mean NPV-S correlated positively with the crude fat and total solids, and negatively with C18:3 c9, c12, c15 (n-3) (α-linoleic acid) content of milk samples, while PSD-S correlated positively with C16:0 (palmitic acid) and negatively with lactose. In the scans obtained with the 5.0-MHz in Olk sheep, the mean NPV-C was directly related to C10:1 (decanoic acid), C14:1 (myristoleic acid), C16:1 iso (iso-hexadecanoic acid), C16:1 c9 (palmitoleic acid), and C18:0 (stearic acid) content; the mean PSD-C correlated positively with total solids, C14:1, C15:0, C16:0, C16:1 iso, C16:1 c9, CLA (conjugated linoleic acids), and total saturated fatty acid content, and negatively with C18:1 c11 (n-7) (cis-vaccenic acid), C18:2 c9,c12 (n-6) (linoleic acid), and total polyunsaturated fatty acid content of milk; and the mean PSD-S correlated directly with ash and total saturated fatty acid content of the milk. Lastly, the mean NPV-C of images recorded with the 7.5-MHz probe in Olk ewes related directly to ash and C12:0 (lauric acid); the mean NPV-S related directly to ash and C16:1 iso; the mean PSD-C correlated positively with ash and total saturated fatty acid (SFA) content, and the mean PSD-S correlated positively with the total SFA. Echotextural attributes of the mammary gland in ewes have the makings of the technique for determining milk content of certain chemical constituents in a breed-specific manner; however, further studies are needed to verify the usefulness of echotextural analyses of the udder to consistently predict complete milk composition.