01161naa a2200217 a 450000100080000000500110000800800410001910000150006024501560007526000090023152005220024065000130076265000240077565000100079965000150080965000170082465000100084165300160085165300180086777300580088515207722024-01-02       1978    bl uuuu     u00u1 u    #d1 aSIERRA, I.  aMejora de la prolificidad en la especie ovina (Ovis aries) mediante cruzamiento; Resultados reproductivos de las Hembras Romanov x Rasa Aragonesa ewes.  c1978  aIt is employed Romanov breed in crossing on the Rasa Aragonesa breed, obtainning a crossed ewe whose reproductive characters (sexual precocity and prolificacy) have been studied. The sexual precocity (fertility at terminus in the first lambing) was 72.39 p. 100 (A) and 70.42 p. 100 (B) in Romanov x Rasa Aragonesa ewes (mated at 5 and 12 months old respectively), versus 30,48 p. 100 (C) and 54.76 p. 100 (D) in Rasa Aragonesa breed (P &lt 0,001 and P &lt 0,05 in A/C and B/D). ... adaptation to ther new enviroment.  aBreeding  aGenetic improvement  aSheep  aCruzamento  aMelhoramento  aOvino  aProlificacy  aProlificidade  tArchivos de Zootecniagv. 27, n. 105, p. 61-71, 1978.