Abstract：
In this work, we investigated cases of birth of calves with congenital defects in a farm in Southern Brazil. Only calves born from heifers were affected, and the disease occurred in both crossbred and purebred calves. Three necropsies were performed, tissues were collected for histopathology, and samples of liver of calves, blood serum, and food provided for cows and heifers were collected to quantify the levels of the minerals: manganese, copper, and zinc. The calves were born weak, with disproportionate dwarfism, limb deformities, and enlarged joints. Heads were shortened and domed. Long bones had a shortened diaphysis and a normal-sized epiphysis, when compared to the control. In one of the cases, there were white-yellowish lines on the metaphyseal surface of the epiphyseal plate. Histopathology of growth plates revealed premature closure, disarrangement of chondrocyte columns, and collapse of primary spongiosa. These findings supported a diagnosis of chondrodysplasia. Liver manganese levels were under the reference values in the three calves. Food analysis revealed insufficient levels of manganese in the diet of heifers, especially in sorghum silage, which was provided as the main source of food for the category in some periods. Approximately 6 months after the diet was changed, the problem ceased and only normal calves continued to be born. Our findings allowed to conclude the diagnosis of chondrodysplasia of nutritional origin and reinforce the thesis that manganese is the mineral deficient in these cases.
摘要：
在这项工作中,我们调查了巴西南部一个农场出生先天性缺陷小牛的病例。只有从小母牛出生的小牛受到影响，这种疾病发生在杂交和纯种小牛中。做了三次尸检,收集组织进行组织病理学检查，和小牛的肝脏样本，血清,收集为奶牛和小母牛提供的食物来量化矿物质的水平：锰，铜，和锌。小牛天生虚弱，不成比例的侏儒症，肢体畸形,和扩大的关节。头被缩短和圆顶。长骨的骨干缩短，骨phy大小正常，与对照组相比。在其中一个案例中,骨phy板的干phy端表面上有白色黄色的线条。生长板的组织病理学显示过早闭合，软骨细胞柱的排列，和主海绵体的塌陷。这些发现支持软骨发育不良的诊断。三只小牛的肝脏锰水平低于参考值。食物分析显示，小母牛饮食中的锰含量不足，尤其是在高粱青贮饲料中，在某些时期被提供为该类别的主要食物来源。饮食改变后大约6个月，问题停止了，只有正常的小牛继续出生。我们的发现可以得出营养来源的软骨发育不良的诊断，并加强了锰是这些病例中矿物质缺乏的论点。
