GENETIC-PARAMETERS FOR LINEAR UDDER TRAITS OF DAIRY EWES

An animal model was used to estimate the repeatabilities and genetic p arameters of linear udder traits of Churra ewes (5265 records from 201 5 ewes). In addition, the phenotypic correlations were examined betwee n log SCC and udder traits. Heritabilities of udder depth (0.16), udde r attachment (0.17), teat placement (0.24), teat size (0.18), and udde r shape (0.24) were similar to those for dairy cattle, making it feasi ble to use data from the proposed linear system in a breeding program to improve the machine milkability of ewes. Genetic correlations among udder traits were generally favorable, implying that selection for im provement of one trait would result in improvement of others. A notabl e exception was the genetic correlation between teat placement and tea t size of 0.62. Vertical placement of teats was associated with larger teats. Also, genetic correlations between udder and yield traits (mil k and protein yields) were small, except for udder depth and teat plac ement. These exceptions predict worsening udder morphology from select ion based solely on milk yield. Phenotypic correlations between udder traits and log SCC indicate that present handling routines led to a gr eater likelihood of infections for deep udders with large teats.