Estudo do tegumento de bovinos e bubalinos para adaptação ao clima tropical

Abstract

The research has been conducted at Universidade Federal Rural do Rio de Janeiro in Seropédica (RJ). Two skin’s samples were collected from the face, neck, shoulder, withers, back, abdomen, tail and cinnamon of seven Sindhi cattle, seven F1Simental x Nelore cattle and seven Mediterranean buffaloes, all males, not castrated and with about two years old. Immediately after collection, by using one of the samples, it was determined skin and hair coat color, between dark or not dark, through visual analysis, and the skin thickness was measured with a caliper. To measure the amount of hair, was defined an area of one square centimeter at the center of the samples, the counting was done manually with magnifying glass and needle. The second sample was fixed in buffered 10% formaldehyde for 24 hours. The samples were stored in 70% ethanol for later processing by routine histologic technique. The processed samples were cut in 5μm thick and stained with hematoxylin and eosin. The histological slides were examined by light microscope. The study aimed to investigate the differences in the number of hairs, sebaceous and sweat glands, hair and skin color as well as the thickness of the epidermis of Sindhi cattle, cattle F1Simental x Nellore and Mediterranean buffaloes. The results show that the buffalo have dark skin and hair, as well as Sindhi cattle, but cattle F1Simental x Nellore had light colored skin and coat. The Mediterranean buffaloes had the highest averages for skin thickness, followed by Sindhi cattle and the smallest averages were found in F1Simental x Nelore cattle. About number of hairs in a square centimeter, buffalo Mediterranean received the lowest average than cattle, which did not differ from each other. For the amount of sweat and sebaceous glands, buffaloes received lowest average than cattle, which did not differ from each other. Considering the results, Sindhi cattle indicate the best conditions to adapt to the tropical climate.