Perfil de Ca, Cu e Zn na epiderme do casco de potros da raça Crioula criados em campo nativo em diferentes regiões fisiográficas no estado do Rio Grande do Sul

Abstract

In view of the importance of the hoof in relation to animal performance, it is extremely necessary that equines have a healthy digital system and in constant equilibrium, and a balanced consumption of nutrients is necessary to prevent imbalances in the epidermal metabolism of the hoof. The aim of the present study was to evaluate the metabolic profile of Ca, Cu and Zn minerals in the epidermal tissues in the pre and post-weaning periods of Criollo foals raised in the native field in different physiographic regions of Rio Grande do Sul. It was used 41 criollo foals from five farms from different regions of the state of Rio Grande do Sul, Brazil. Two moments were considered: pre and post weaning. Samples of keratinized epidermal tissue were collected by means of a rasp in the dorsum-proximal section of the hoof walls of both anterior limbs, obtaining two grams of bran. Samples were collected from forages and, subsequently, ten soil samples per property. All samples were evaluated by Atomic Absorption Spectrometry. The chemical composition between fetal and definitive hull was determined taking into account the location of the fetal growth line in relation to the hull crown, considering three stages of evaluation. Variations occurred in the mineral concentrations of Ca, Cu and Zn between the fetal hull (Ca: 571.0 ± 139.4, Cu: 14.5 ± 7.6 and Zn: 130.0 ± 30.5 mg kg-1 , P <0.05) and definitive (Ca: 653.0±162.9, Cu: 33.0±11.5, Zn: 69.3±36.8 mg kg-1 ; P<0,05), in pre weaning (Ca: 620.0±184.0, Cu: 17.2±21.2, Zn: 103.0±75.5 mg.kg-1 ; P<0,05) and post-weaning (Ca: 517.5±181.0, Cu: 0, Zn: 79.0±41.7 mg kg-1 ; P<0,05). There were also variations in the concentrations of Ca, Cu and Zn in the epidermal tissue of the criollo colts between distinct physiographic regions (P<0,05), and according to the seasons. There was positive correlation with the age range pre-weaning criollo colts for Ca and Cu (r= 0,5, 0,57; P<0,05) and negative for Zn (r= -0,69; P<0,05). As for post-weaning, positive relation between Ca and Z (r= 0,36, 0,64; P<0,05) and negative for Cu (r= -0,39; P<0,05). No correlation was found between the Ca concentrations (P>0,05) in the epidermal tissue of the hull of criollo colts, in both pre and post-weaning, and the native pasture. Correlation was found between the native pasture and the hull epidermal tissue in pre-weaning coolts for Cu and Zn (r= 0,69, 0,43; P<0,05). As for Cu in post-weaning (r= 0,74; P<0,05). Therefore, this study determined the mineral concentrations of Ca, Cu and Zn in the epidermal tissues of the hull of Criollo foals are different between fetal and definitive hull, verifying the difference in the concentrations of these constituents from birth to post-weaning, as for distinct seasons and physiographic regions in the state of Rio Grande do Sul, Brazil.