Table salt as a salivary stimulant and buffer substitute in calf diets: Effects on growth performance, rumen...

This study evaluated sodium chloride (NaCl) as a natural salivary stimulant and a substitute for conventional buffers in calf diets. We hypothesized that varying the amount and method of NaCl provision would modulate salivation, rumen fermentation, and growth performance. Fifty Holstein calves (46.43 ± 2.19 kg BW; 10 ± 5 days old) were assigned to five treatments in a completely randomized design: T1 (Control, NRC-salt mixed in feed); T2 (NRC-salt, 15% pre-fed); T3 (2 × NRC-salt, mixed); T4 (2 × NRC-salt, 15% pre-fed); T5 (NRC-salt + 0.5% NaHCO₃ buffer). Treatments significantly (P < 0.05) affected dry matter intake (DMI), feed conversion ratio (FCR), nutrient digestibility, saliva and rumen pH, and volatile fatty acid (VFA) profiles. Although T5 (buffer) promoted the highest saliva volume and DMI, T4 elicited the highest saliva pH and the most favorable FCR, owing to enhanced salivary buffering capacity and a shift in rumen fermentation toward greater propionate production, despite a lower ruminal pH. Blood parameters remained unaffected across treatments. Health indicators improved in all salt-supplemented groups, with T4 showing the lowest fecal score. An economic analysis projected annual savings of approximately $5,593 for a 5,000-head herd when replacing NaHCO₃ with the T4 NaCl strategy. We conclude that strategic supplementation with NaCl (specifically at twice the NRC level with a portion pre-fed) can effectively enhance salivary buffering, improve feed efficiency, and serve as a cost-effective natural alternative to chemical buffers in pre-weaned calf nutrition.