Aspects of ingestive behavior in cattle.

: Ingestive behavior in cattle differs from other species because of physiological mechanisms developed pari passu with fermentative digestion. The secondary refection of rumination allows remastication and reinsalivation of the large bulk of vegetable food ingested. The need to buffer acid products of cellulose digestion demands continuous high secretion of alkaline saliva. Nervous and hormonal stimuli emanating from the gastrointestinal tract evoke centrally controlled behavior of hunger and satiety. The four primary taste receptors occur in cattle but thresholds are low. Because of the low Na level in plants, cattle have developed the behavior of seeking salt by taste and smell. During Na deficiency it can be shown that cattle readily learn and develop memory, providing a powerful behavioral dimension in the search for food.