title: Serum leptin levels in cattle with different nutritional conditions.
abstract: The role of leptin as an energetic state indicator in cattle was evaluated correlating different nutritional conditions and serum leptin levels. Two experiments were developed. Experiment I: Polled Hereford heifers were fed in optimum conditions and assigned randomly to one of three treatment diets: grazing, grazing plus supplementation and feedlot. Experiment II: cattle were subjected to feed restriction (R). Serum leptin levels were measured at pre and post-feeding moments. Using serum free fatty acid (FFA), beta-OH Butyrate (beta-OHB) and protein concentration as serum energetic indicators in both experiments. In experiment I leptin values were significantly different between pre and post-feeding moments, similar differences were found among groups when the pre-feeding and post-feeding values were compared. These differences may be considered as changes associated to the control of food intake. In experiment II, the serum leptin levels in Group R were significantly lower. The poor energetic status of animals from group R was demonstrated by the serum FFA, beta-OHB and protein concentrations. These results suggest that the energetic status of animals is correlated with the serum leptin levels, tending to maintain the energetic homeostasis.
authors.affiliation: Departamento de Fisiopatología, Facultad de Ciencias Veterinarias, UNICEN, Pinto 399, 7000-Tandil, Argentina
authors.forename: A S.
authors.initials: AS
authors.lastname: Sansinanea
authors.forename: S I.
authors.initials: SI
authors.lastname: Cerone
authors.forename: I
authors.initials: I
authors.lastname: Zonco
authors.forename: C
authors.initials: C
authors.lastname: García
authors.forename: N
authors.initials: N
authors.lastname: Auza