ARGININE IN LIQUID CONTENTS OF DISPLACED ABOMASA IN DAIRY COWS

Increased nitric oxide synthesis by abomasal neurons was related to di sorders of abomasal muscle function in displaced abomasum in a previou s study. Nitric oxide is synthesised from L-arginine. The objectives o f the studies reported on here were to isolate factors associated with arginine in abomasal fluid and to evaluate the association between ar ginine in abomasal fluid and left displaced abomasum (LDA), right disp laced abomasum (RDA) or abomasal volvulus (AV). Four cows fitted with abomasal cannulas were fed two different diets in succession. Abomasal samples were taken from 1.00 a.m. to 11.00 p.m. during each diet. The data were analyzed using three factor analysis of variance. Diet, sam pling time and cow were significantly associated with abomasal arginin e concentration. Diet and cow significantly affected abomasal arginine percentage, whereas sampling time had no significant effect. Cows dia gnosed with LDA, RDA or AV and control cows were used to study the ass ociation between abomasal arginine and LDA, RDA or AV. Linear regressi on of arginine on LDA, RDA or AV, adjusting for age, time to calving, duration of illness and intraherd correlation was used for data analys is. Associations between arginine concentration and LDA or RDA, and be tween arginine percentage and LDA, RDA or AV were not significant. AV significantly increased abomasal arginine concentration. The findings do not support the hypothesis that arginine in abomasal fluid is relat ed to abomasal displacement in dairy cows.