Seasonal Variations of yeso sika Deer Skin and its Vegetable Tanned Leather

Yeso sika deer is one of the red deer species inhabited Hokkaido and exhibits seasonal molt twice a year. We investigated seasonal variations of morphological and biochemical characteristics of yeso sika deer skin as well as physical, chemical and morphological properties of its vegetable tanned leather. Morphologically, in spring and autumn, which is just active phase of molting cycle, yeso sika deer skins had thick hair fibers, therefore there is many hair follicular spaces in the skin, and many inter fiber spaces were observed by SEM. From biochemical analysis, water, ash and fat content did not vary with the seasons. Protein content of skins in spring and autumn was higher than winter or summer skins, which is just resting phase of molt. Inversely collagen content of these skins was lower than winter or summer skins. Although raw skins showed some seasonal variation in its characteristics, vegetable tanned leathers of yeso sika deer were not so different with the seasons in its tensile strength, shrinkage temperature. Overall, yeso sika deer leather has high degree of water absorption. Our findings suggest that yeso sika deer skin is good material for leather manufacture.