Resumen

RIERA-NIEVES, Mario et al. Comparison of Morphological Traits of Teats in Three Dairy Breeds. Rev. Cient. (Maracaibo) [online]. 2006, vol.16, n.4, pp.315-324. ISSN 0798-2259.

Morphological traits of teats and teat-end were evaluated from August 2003 to February 2004 in 1263 Carora, 403 Holstein and 118 Jersey cows reared in Venezuela. Teat type was classified as funnel, cylindrical and bottle whereas teat-end was classified as pointed, round, flat, disk, funnel shape and prolapsed. Also, the length and diameter were measured for each teat. The aim of this work was to evaluate the morphological effect of breed on the teat treats. Teat length and diameter were analyzed by a mixed model including the fixed effects of breed, age of cows, herd- birth year interaction and the random effect of the cow within herd. Teats and teat-end types were analyzed by SAS version 8.0 with the Proc. Freq and Proc. Univaríate. In order to associate the teat traits with the breed was used Chi square (c²). Carora breed showed a significant effect on teat length and diameter: the estimated teat length was 5.9, 5.4 and 5.3 cm and the estimated teat diameter was 2.3, 2.2 and 2.1 for Carora, Holstein and Jersey, respectively. Teat length and diameter increased as the age increases. No significant effect of breed was found for teat and teat-end type but in the three breeds there was predominance of round and pointed shape.

Palabras clave : Teat shape; teat-end types; dairy breeds.