Arginine in liquid contents of displaced abomasal in dairy cows

Increased nitric oxide synthesis by abomasal neurons was related to disorders of abomasal muscle function in displaced abomasum in a previous study. Nitric oxide is synthesised from L-arginine. The objectives of the studies reported on here were to isolate factors associated with arginine in abomasal fluid and to evaluate the association between arginine in abomasal fluid and left displaced abomasum (LDA), right displaced 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, sampling time and cow were significantly associated with abomasal arginine concentration. Diet and cow significantly affected abomasal arginine percentage, whereas sampling time had no significant effect. Cows diagnosed with LDA, RDA or AV and control cows were used to study the association between abomasal arginine and LDA, RDA or AV. Linear regression of arginine on LDA, RDA or AV, adjusting for age, time to calving, duration of illness and intraherd correlation was used for data analysis. Associations between arginine concentration and LDA or RDA, and between 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 related to abomasal displacement in dairy cows.