Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Pedigree analysis of eight Spanish beef cattle breeds | Genet. Sel. Evol. 35 2003 43-63 43 INRA EDP Sciences 2003 DOI gse 2002035 Original article Pedigree analysis of eight Spanish beef cattle breeds Juan Pablo GUTIÉRREZa Juan ALTARRIBAb Clara DÍAZc Raquel QuINTANILLAd Javier CANÓNa Jesus PIEDRAFITAd a Departamento de Producción Animal Facultad de Veterinaria Universidad Complutense de Madrid 28040 Madrid Spain b Departamento de Anatomía y Genética Facultad de Veterinaria Universidad de Zaragoza 50013 Zaragoza Spain c Departamento de Mejora Genética Animal INIA Carretera de la Coruna Km 7 28040 Madrid Spain d Departament de Ciència Animal i dels Aliments Facultat de Veterinària Universitat Autònoma de Barcelona 08193 Bellaterra Barcelona Spain Received 16 November 2001 accepted 7 August 2002 Abstract - The genetic structure of eight Spanish autochthonous populations breeds of beef cattle were studied from pedigree records. The populations studied were Alistana and Say-aguesa minority breeds Avilena - Negra Ibérica and Morucha dehesa breeds with a scarce incidence of artificial insemination and mountain breeds including Asturiana de los Valles Asturiana de la Montana and Pirenaica with extensive use of AI. The Bruna dels Pirineus breed possesses characteristics which make its classification into one of the former groups difficult. There was a large variation between breeds both in the census and the number of herds. Generation intervals ranged from to years tending to be longer as the population size was larger. The effective numbers of herds suggest that a small number of herds behaves as a selection nucleus for the rest of the breed. The complete generation equivalent has also been greatly variable although in general scarce with the exception of the Pirenaica breed with a mean of . Inbreeding effective population sizes were actually small 21 to 127 especially in the mountain-type breeds. However the average relatedness computed for these breeds suggests that a slight exchange of animals between .