Wool production of Romney Marsh Criollo Chiapas sheep breed and their crosses analyzed by random regression

Abstract

Wool produced (kg of fleece/shearing) by 371 sheep from the genetic groups of Romney Marsh (31) Criollo Chiapas sheep (135) and their hybrids (205) was analyzed using repeated measures models and random regression analysis. One thousand one hundred and eight production records collected over a period of 12 years, under extensive production conditions in the region of the Altos de Chiapas, Mexico, were analyzed. The genetic groups displayed wool production differences (P 0.06), but lesser than the last ones (P < 0.05). Criollo sheep showed remarkable environmental adaptation; therefore, the preservation of this animal genetic resource is extremely important for the indigenous community that makes use of it. Key words: Criollo sheep, heterosis, wool production, random regression.