SUMMARY

In 1989 academics of the Universidad Nacional de Lomas de Zamora, Facultad de Ciencias Agrarias (National University Lomas de Zamora-Agrarian Academy) discovered a wild  population of pure Creole bovines. These animals were located in the National Park Los Glaciares (50º 20’ S Latitude and 72º 18’ W Longitude), in the very end of the patagonic area of Argentina. This population (considered in 1000 units) was denominated “Patagónico” (PAT). Until this discovery the only genetic reservoir of Argentine Creole bovines recognized by the Breeders Association and the National Institute of Agro-Farming Technology (INTA), was located in the northwest area of Argentine (NOA) with a considered population of 200.000 heads. Both populations have had the same origin (introduced by Spanish colonists), but have had a different evolutionary experience. While the PAT has been living for 250 years in a cold zone, the NOA has been developed in a subtropical zone. The objective of this work has been to describe both genetic and morphologically the Creole bovine of Patagonic origin, and to compare it with the NOA population. The morphological characterization has been carried out on a 259 adult bovine’s sample distributed in the following way: females NOA (NH=80), males NOA (NM=33), Patagonic PAT (PH=115) and Patagonic PAT (PM=31). The coat colour has been described and thirteen zoometric variables have been measured up (six of head and seven of the trunk), that have been fit by age according to sex. Recorded measures have been: Wide of Head (AC), Length of Head (LC), Wide of Ear (AO), Length of Ear (LO), Base of the Horn (BC), Size of the Horn (TC), Thoracic Perimeter (PT), Length of Body (LT), Withers Height (ACr), Rump Height (AG), Wide previous of Rump (AAG), Wide later of Rump (APG) and Length of Rump (LG). With these measures five zoometrics indices have been constructed: Cephalic Index (ICEF), Lateral Corporal Index (ICL), Corporal Index (IC), Index of Anamorphosis (IA) and Pelvian Index (IPE). To analyse the morphologic data we have used the SAS package The genetic characterization has been done analysing 36 PAT animals and 45 NOA animals with 27 microsatellites (BM8125, BM1314, BM1818, CSSM66, ETH10, INRA32, MM12, TGLA122, BM2113, CRSM60, ETH185, HAUT27, HEL13, HEL9, ILSTS06, INRA23, INRA37, INRA63, SPS115, TGLA227, BM1824, ETH225, ETH3, HAUT24, ILSTS11, INRA35 and TGLA53) recommended by FAO in bovine biodiversity studies. Eight additional breeds were used as reference populations in genetic distance studies: Pajuna (PAJ=43), Palm (PAL=40), Canary (CAN=40), Mottled Red (BCOL=44), Mottled Black (BNEG=40), Marismeña (MAR=32), Holstein ( HOL=28) and Hereford (HER=25). To analyse the genetic data, we used several statistical methods and programs: GENEPOP v.3.1c, GENETIX v.4.05, MICROSATELLITE TOOLKIT MS Excel, POPULATIONS v.1.2.28 and STRUCTURE v.2.1. The results of the morphologic qualitative comparison have shown differences in the frequencies of the coat colour (Red and Hosco) and of the pigmentation between PAT and NOA. As far as the zoometrics characteristics, PAT creoles, in general have been smaller, long lines and of greater variability that the creoles than the NOA, that have shown greater dimensions and uniformity. The sexual dimorphism has been marked in the two populations. The observed genetic variability in PAT has been moderate (Na = 5.04; Ho =0.5795), and smaller than in NOA (Na = 5.93; Ho = 0.6663). From the total 179 total allelic variants found, PAT and NOA did not share 62 that are 35%. PAT Creole has displayed greater homocigosis than the NOA (Fis multilocus PAT = 0.06579 and NOA = -0.00913). Fst Multilocus (0.1175) has shown moderate to high genetic differentiation between the PAT creoles and those of the NOA creoles. The Factorial Analysis of Multiple Correspondences has shown the individuals of both populations separated in two clusters divided by the first factorial axis. In the study of the genetic structure, the assignment of individuals to two clusters has grouped 97 % of the PAT in a cluster and 97% of the NOA in the other. When the assignment has been carried out considering 3 and 4 clusters, it has been observed that the PAT has maintained their homogeneity, whereas the NOA has been more heterogeneous. In the genetic distance studies the most distant breed from PAT has been HER, whereas the most distant breed from NOA has been PAL. The genetic distance obtained between PAT-NOA, has been similar to the distance found between PAT and other pure breeds (PAT-BCOL, PAT-CAN and PAT- HOL) The observed genetic differentiation between PAT and NOA reflects and explains the historical process and the different evolution that both populations have undergone. The pampean origin of the PAT, your reproductive isolation and the permanency during more than twenty generations in a cold climate favored the genetic differentiation with the Creole of the NOA who has remained in subtropical climates. Though it is difficult to determine the limit to catalogue the PAT as a variety inside the breed and even as an independent race, having in it counts the international current criteria, is suggested in any case, to keep genealogical records separated to assure the conservation of the major genetic possible diversity.