Influência da pigmentação nas características físico-mecânicas e na composição química de cascos de ovinos Morada Nova

The objective of this work to evaluate the influence of depigmentation of hulls Morada Nova sheep, through the physical and mechanical properties and the chemical composition. 40 animals were evaluated in the growing phase, whole, male, was collected after slaughter hooves for testing physical and mechanical resistance. Was collected every hoof of the animal at the time of the ticket, with the aid of a knife made to disarticulation. Was collected 18 samples, 6 for each group, hoof black, brindle and white, respectively. The samples were prepared from each animal digit side, cuts being made of the sole case of the insertion of the middle phalanx and the distal phalanx with. The preparation of the material for microscopic analysis followed the longitudinal wall of the hull, the kit being harvested corneum. After cutting the material, it remained in the oven for 24 hours to remove all moisture. Then the samples are placed in "stubs", fixed with carbon tape and taking them to bath with gold (colloidal) and examined by scanning electron microscopy (SEM). Of the 40 evaluated animals before slaughter, 17 had partial or complete depigmentation of the nasal and ocular mucosa, representing (42.5%). There were significant differences between treatments analyzed, and that the treatment the hulls of black showed higher initial resistance when compared with the hooves color brindle and white, for the variable force (N). Despite the treatment related to black hulls show a greater initial resistance observed displacement (mm) similar among treatments. There was no significant difference (P> 0.05) between the variables of chemical composition, except for crude protein, which showed a significant difference (P 0,05) para entre as variáveis de composição química, exceto, para proteína bruta, que apresentou diferença significativa (P < 0,05). Observando a disposição das lâminas epidérmicas, percebeu que apresentaram mesma micro-estrutura em sua superfície queratinizada interna e externa, fato que não evidencia desqualificação na estrutura do casco desses animais quando associa-se a despigmentação. Ovinos Morada Nova com cascos apresentando diferentes níveis de pigmentação, não apresentam diferenças de suas características físico – mecânicas e de composição química