Parbhani, 431 402 (MS) IndiaFOOT-AND-MOUTH disease (FMD) is one of the most economically important diseases of cloven-footed animals. The direct economical losses due to FMD are caused by the reduction in milk production and draught power, the cost of treatment, and the deaths of young animals. Indirect economical losses are due to conditions such as panting syndrome, abortion, infertility, permanent disability, and permanent loss of lactation. Most of the work being carried out on FMD is concerned with prophylactic measures by vaccination, and treatment, but the factors which cause groups of animals to become susceptible to FMD are unknown. The levels of certain metabolites in the blood may indicate various types of stress, resulting in an animal or a herd under a given managemental system possibly becoming susceptible to certain diseases (Payne and others 1973). This short communication describes a study which was undertaken to investigate the differences in the metabolic constituents of blood in healthy cattle and cattle with FMD.Two groups of cattle were used, one consisting of 48 naturally affected FMD cases and the other consisting of 11 healthy cattle. The animals were of a local breed and both groups contained both male and female cattle. The animals were kept under a free-range system with optimum maintenance requirements. Their feed consisted of a concentrate mixture provided for their optimal maintenance, and jowar (sorghum), kadbi or greens (lucerne or maize) according to the availability of fodder.Blood samples were collected from the animals, using 25,000 iu heparin sodium (Evans Biological) as an anticoagulant, in the morning, before the animals were fed or watered. Another blood sample (approximately 10 ml) was collected from each animal in order to obtain serum. The plasma and serum samples were stored at -20°C until used for biochemical analysis. Fresh blood samples were analysed within 24 hours of collection for biochemical constituents. Standard methods were used to determine the levels of blood glucose (the method of Foline and Wu, as described by Oser [ 1965]), serum cholesterol (the ferric chloride method, as described by Nath [ 1976]), serum urea nitrogen (the DAM urea method), total serum protein (the Biuret method) and serum albumin (the BCG dye binding method). The serum globulin values were calculated as the difference between total protein and albumin, and from this the albumin:globulin ratio was estimated. Statistical analysis was carried out by using an FMOaffte cattl Healthycatl Metabolite mean(* Range Mean (se) Range P Blood glucose (mmol/litre) 446 (0.15) 2-35-7*77 3.15 (0.03) 2.99-3-21 <0.01 Serum urea nitrogen (mmol/litre) 4-Albumin:globulin ratio 3-35 (1-00) 1-25-2-95 4-07 (4.00) 5.44-2-60 >0-05 unpaired t test (Panse and Sukhatme 1965). The values of various metabolites in two groups are shown in Table 1.Comparison of the mean values for blood glucose between the two groups showed a significantly higher (P<0-01) glucose level in the FMD-affected cattle. Recent research has su...