why salivary amyalse is absent in the herbivorous and carnivorous like cow buffalow lion tiger etc but present in the pigs

Salivary amylase is present in pigs because they have starch rich diet. The diet of herbivores such as cow and buffalo is rich in cellulose whereas carnivores have protein rich diet. Salivary amylase works on starch and breaks it into smaller disaccharides.