The objective of this study was to evaluate the influence of crossings between sheep breeds on the intrinsic quality of leather. It was used the skins of 36 lambs (18 females and 18 males), resulting from crosses between ewes of a native breed from the Brazilian state of Mato Grosso do Sul and rams of the same native breed as well as the Texel and Santa Inês genetic groups. The animals were raised in confinement until slaughter weight, from 28 to 32 kg. After slaughter, samples were taken from the skins for histological analysis. The skins were tanned with chromium, retanned and greased. It was taken from the leather samples for electromicrographs and for tests for tensile and tear strength (intrinsic quality). Morphological aspects from the skin as well as from the leather help to understand the results found and they evidence that breeds or crossings among breeds interfere in the intrinsic quality of leather and skin of sheep.

Objetivando-se analisar as características físico-mecânicas do couro de caprinos, após o curtimento, utilizaram-se 16 animais machos mestiços Alpinos, com idades a partir dos 180 dias de vida, abatidos em intervalos de 45 dias (quatro animais por abate). As peles foram curtidas e recurtidas e dos couros retiraram-se três corpos-de-prova das regiões dorsal, paleta, ventral, anca e lateral, nas direções paralelas e perpendicular ao eixo crânio-caudal, para realização dos ensaios físico-mecânicos: distensão da "flor" no lastrômetro, rasgamento progressivo, resistência à tração, análises químicas de extração de lipídios, óxido de cromo, pH e cifra diferencial. A idade do animal exerceu efeito positivo no ensaio de resistência à tração, com superioridade para os caprinos de 315 dias de vida. A região e a posição em todos animais estudados apresentaram efeito significativo no ensaio de resistência ao rasgamento progressivo, nas quatro idades, atingindo o valor de referência mínima de 80 kgf/cm. A resistência do couro à distensão da "flor" dos caprinos estudados foi superior ao mínimo de 7 mm, demonstrando grande elasticidade dos couros, sem influência de idade ou região.

This paper focuses on the analysis of goats leather to identify the physical and mechanical characteristics after toning. Sixteen male crossbred Alpine goats, with four animals from 180 days old by slaughter, were used. Slaughter intervals of 45 days were used. The skins were tanned and re-tanned, and from the breather the proofs from the dorsal, palette, ventral, hind and lateral regions, were taken, in the following directions: parallel and perpendicular to the tail-skull axis, so that the physic-mechanic studies could be performed: distention of the "flower" in the lastometer, progressive tearing; resistance to traction and chemical analyses of fat, chrome, pH and differential code. Animal age showed positive effect on traction resistance, with high values to goats at 315 days old. The region and position of all animals studied shower significant effect on the four reach ages, reaching the minimum reference value of 80 kgf/cm. Bather resistance to distention of the "flower" from the goats were superior to the minimum of 7 mm, showing the great elasticity of the bather, with no effect of age or region.