The Effects of Different Factors and Heterosis on Body Dimensions of Awassi, Chios and their Crossbred Lambs

The demand for lamb meat is rapidly growing in the Jordan market where body and tail dimensions, in particular, are commercially important in judging meat lambs. This study aims to present effects of different factors and heterosis on body and tail dimensions of Awassi, Chios and their reciprocal crossbred lambs. Significant effects of year, sex, age, and sire and dam breed were obtained on some traits. The significant twoway interaction effects were also obtained. For example, birth type-sex had significant effect on body length, shoulder width, heart girth, tail circumference and tail width. Furthermore, sire breed-sex significantly affected tail width, whereas dam breed-sex significantly affected rear leg height, tail circumference and tail width. Heterosis effects were always in favor of crossing Awassi sire with Chios ewe. Moreover, lambs from this crossing had similar dimensions of tail length, width and circumference as pure Awassi which is favored by local market over thin tailed sheep.