Abstract
Hypomagnesemic tetany is a metabolic disorders occurring in cattle grazing on lush grass pasture (grass tetany), or in heavy lactating cattle (lactating tetany), or during cold weather (winter tetany). All these stressors as well as increasing concentrations of other minerals in diet such as potassium, which interfere with the absorption of magnesium causing hypomagnesemic tetany. The aim of this study was to determine the biochemical changes in serum and acute phase response in cattle with hypomagnesemic tetany. This investigation included 11 lactating cows suffered from nervous manifestation such as fast movement of the eye ball, muscular tremors, stiffness in gait and convulsion. Blood samples were collected from affected animals and 15 apparently healthy lactating cows (control group). Total protein, albumin, glucose, hepatic and muscular enzymes, serum minerals including Ca, Mg, P, K, Na, Cl and acute phase proteins (APPs) including (Haptoglobin, serum amyloid A, C-reactive protein) were measured using commercially available test kits. The result revealed significant decreases in serum total protein, albumin and glucose in blood of diseased group. On the other hand, there were significant elevations in both hepatic and muscular enzymes activities including AST, ALT, GGT, CPK, LDH, and AP while serum electrolytes levels were variables. The affected cattle showed significant hypomagnesemia, hypocalcemia and hyperkalemia. There were highly significant increases in APPs in diseased cattle. It can be concluded that hypomagnesemic tetany in cattle is a complex metabolic disorders associated with acute inflammatory response assessed by APPs, which could be used in the future as a prognostic indicators for such disease in cattle.

Key words: Acute phase proteins, biochemical parameters, hypomagnesemic tetany, cattle