Heritabilities of Teat Traits and their Relationships with Milk Yield, Somatic Cell Count, and Percent Two-Minute Milk

Two teats on one side of the udder of 898 Holstein cows were scored on a continuous scale for shape, orientation, and pigmentation. Corresponding teat ends were scored for shape, lesions, pigmentation, and orifice location. Teat lengths and diameters, udder height, and distances between teats were measured on the same day. Cows were from six herds owned by the North Carolina Department of Agriculture and two North Carolina State University research herds. Repeatabilities from 98 cows rescored 6 mo after initial scoring were: .54, teat shape; .76,teat-end shape;.98, teat pigmentation; .98, orifice pigmentation, and .32, lesion score. Heritabilities based on 72 paternal half-sister groups were: .38, teat shape; . 5 5, teat-end shape;, 55, teat pigmentation; .40, orifice pigmentation; .24,lesion score; .19, orifice location. Those for four traits of teat orientation averaged .18. Corresponding heritabilities from 200 cow-dam pairs were .37, .67, .55, .30, .22, and .48. Teat-end shape was related to somatic cell count and percent 2-min milk. Somatic cell counts were influenced by udder height, teat-end shape, percent 2-min milk, lesion score, and teat diameter. Teat shape, length, diameter, pigmentation, and orientation did not have large effects on economically important traits.