Assessment of thyroid hormones, insulin and magnesium in dairy cattle with subclinical ketosis

Ketosis, with ethologically energy deficiency, is one of the commonest metabolic diseases of dairy cattle. Assessment of some serum hormonal and metabolic status can be beneficent in prediction and diagnosis of subclinical ketosis. This study is performed for evaluation and comparison of thyroid hormones, insulin and magnesium of subclinical ketosis and healthy cows. During 60 days in milk (DIM) serum Beta hydroxy butyric acid (BHBA) and glucose levels of 200 dairy cattle have been measured. Based on 1.4 mmol/l of BHBA as a cut of point experimented animals separated to subclinical and healthy groups. Mean values of serum T3 and T4 of affected cows were significantly higher than non-affected (p<0.05). On the other hand, magnesium and insulin level of subclinically cases were significantly lower than control group (p<0.01 and p<0.05 respectively). There was significant correlation coefficient between BHBA and insulin levels of ketosis cows (p<0.05, r=0.37). In conclusion, increasing levels of thyroid hormones and decreasing magnesium and insulin of subclinically affected cattle could be used for diagnosis and prediction of this kind of ketosis at the herd level.