Morphological traits in Portuguese Bordaleira de Entre Douro e Minho sheep: divergence of the breed

Abstract

Production of the autochthonous Portuguese sheep breed Bordaleira de Entre Douro e Minho (BEDM) is directly associated with the concept of sustainable agriculture. This concept focuses on the adaptation of animal populations to adverse environmental conditions, high biological efficiency and traditional management. Native BEDM sheep can be divided into the following two types on the basis of their geographic location in Portugal and how they are managed: the Várzea, which is found mainly in the lower Entre Douro e Minho region, and the Mountain type, which traditionally prefers common areas. In the present work, we analysed records of liveweight, 15 body measurements and eight indexes of the BEDM sheep, to explore the ability to distinguish different characteristics between BEDM sheep populations. The records that were obtained and analysed by principal component analysis for 412 BEDM sheep (68 males and 344 females) included the following: heights at withers (HW), at back (HB), at rump (HR) and at chest (HC); lengths of trunk (LT), of rump (LR), of head (LH) and of perineum (LP); widths of head (WH), of chest (WC), of biiliac (WBIIL) and of biischiatic (WBIIS); perimeters of the shin (PS), thorax (PT), and abdomen (PA); and finally indexes such as cephalic index (CI), thoracic index (TI), pelvic index (PI), body index (BI), relative chest depth index (RDCI), lateral corporal index (LCI), relative shin thickness index (RTSI) and dactyl–thoracic index (DTI). The Várzea BEDM was morphologically superior to the Mountain variety, with this superiority more evident in females. Height measurements, especially HW in adult females, provided an excellent measurement reference for biometrical breed studies. Functional index values confirmed the BEDM Mountain variety’s appropriateness for mountainous regions. Relationships among body measurements suggested that the breed standard needed to be updated. The research presented here was used by the Portuguese Ministery to split BEDM into two new breeds; the traditional variety called Várzea now represents the new BEDM breed, whereas the Mountain variety represents the new Churra do Minho breed.