Abstract
Livestock activities, mainly those related to livestock rearing, are generally carried out in special and specific environments, susceptible to alterations, with particular and inherent characteristics of soil, vegetation and climate, not conducive to the development of the farming. Paraguay is no exception, because more than half of its territory is made up of semi-arid and wetlands, one of the most representative being the Ñeembucú wetlands and its areas of influence. In this area, the presence of certain genetic groups made up of local or naturalized bovines and bovines of transnational or exotic genetics stands out. The aim of this work was to assess protein status in cattle during the summer, fall, and winter as an indicator of adaptation to the wetlands of Ñeembucú, Paraguay. The study compared local and exotic breeds in an extensive cattle farming system, grouped by genotype into Criollo Ñeembucú; Criollo Pilcomayo; Nelore; Brangus, and Brahman. Blood levels of urea, creatinine, total protein, albumin, globulin, albumin/globulin ratio, and body condition were analyzed. The local criollo breeds had higher urea concentrations, total protein, and globulin values, most markedly in the summer. The exotic breeds had elevated creatinine levels. Nelore had the lowest marks for body condition both in the summer and winter. The analysis of main components explained over 60 % of the variation. Globulin and total protein integrated the first component in all three seasons. The most dissimilar breed pairs were Criollo Ñeembucú and Brahman, and also Criollo Pilcomayo and Nelore. The results suggest an adaptation process in the metabolic pathways of nitrogenated compounds and the potential capacity for immune response in local breeds. The results suggest that exotic breeds have mechanisms that compromise tissue protein integrity and renal function in the specific environments particular to the wetlands of Ñeembucú.