Lysozyme activity in buffalo and bovine abomasum.

Basing on the hypothesis that the lower purine derivatives excretion detected in buffaloes respect to bovines may be due to a lower lyses of rumen bacteria, the lysozyme activity in the abomasums of the two species was studied. Six buffalo and six dairy cows fed a standard diet (NDF 43% DM; CP12% DM) for three month before slaughtering were included in the trial. Samples from three areas of abomasum mucosa (fundus, pylorus and cardias) were dissected, washed and stored at -20°C. After 24 h, the samples were homogenised, centrifuged and the supernatants were analysed by using lyophilized Micrococcns luteus and lyophilized lysozyme from egg. The transmittance of the suspensions was analysed by spectrophotometer, repeating the reading each minute for 10 minutes. Lysozyme activity unity was estimated as 1% of transmittance increase/min. No differences were detected between the species. The lysozyme activity was affected by the site of sampling: close to 600 unit/g of mucosa in the samples from fundus, 235 u/g in pylorum and only 7.0 u/g in cardias. In conclusion, the differences in purine excretion between buffalo and bovine should not be ascribed to abomasum lysozyme activity.