Abstract
Because left displacements of abomasum cause great economic losses among dairy cattle production, so this study was aimed to evaluate the main hemato-biochemical alterations, urinalysis, milk ketones, determination acid base balance and ultrasonographic findings of cows with left displaced abomasum (LDA). This study was performed on forty five Holstein dairy cows; fifteen cows were clinically healthy and kept as a control group; the other thirty cows showed signs of abomasal displacement that involve anorexia, sudden fall of milk yield, scanty pasty faeces even some showed diarrhea containing parts of grains, colic and ketotic odour of the breath. Simultaneous percussion and auscultation of the upper left flank, particularly on the cranial third of para lumbar fossa and between 9th and 12th rib, a characteristic tinkling sounds were heard. Ultrasonographically, the displaced abomasum was clearly visible between the left 10th and 12th ICS in all cows. Hypo echoic content of abomasum appeared at left ventral region, gas cap with reverberation artifact appeared at left dorsal region. Laboratory findings of abomasal displaced cows showed a significant hyponatremic hypochloremic hypokalemic metabolic alkalosis with hypocalcaemia, hypophosphatemia, ketonuria and aciduria. Serum values of total protein, albumin, globulins, cholesterol, triglycerides and glucose were significantly decreased. On other hand a significant increase was found in serum concentrations of urea, creatinine, ALT, AST and BHBA in cows suffered from Left Displaced Abomasum (LDA). Oxidant-antioxidant study showed a significant increase in the levels of nitric oxide and malondialdehyde while, serum activity of total antioxidant capacity demonstrated a significant lowering in LDA affected cows. LDA increased lipid peroxidation so the interference by antioxidative agent during the treatment of such cases is beneficial.

Key words: left displaced abomasum , dairy cows, antioxidant , oxidative stress