摘要：Considering the facts that Istrian sheep is Croatian indigenous breed with the highest milk production, and increasing interest of local farmers for machine milking implementation, the aim of this study was to determine the factors affecting udder morphology traits of Istrian ewes. Ninetythree purebred Istrian ewes with symmetrical udders and no signs of clinical mastitis, from second to fourth lactation, were used for this study. Average udder depth of Istrian ewes was 15.85 cm, udder width 13.05 cm, udder circumference 39.66 cm, cistern height 1.44 cm, teat position 2.85 (scored from 1 to 5), teat angle 47.32°, teat length 3.43 cm and teat width 2.03 cm. The traits related to udder size (depth, width, and circumference) were significantly (P<0.01) affected by lactation milk yield. These traits were also in high and positive correlations (P<0.01) with daily milk yield. With the increase of parity, the morphological aptitude of udder to mechanical milking become worse, with an increase (P<0.01) of cistern height, teat angle and position. As lactation of Istrian ewes continued morphological traits defining udder aptitude for machine milking improved (decrease of cistern height, teat angle and position). Ewes with two and more lambs had larger udder (P<0.05) than ewes with a single lamb.
关键词：mammary gland; udder traits; machine milking; parity; stage of lactation
