Table salt as a salivary stimulant and buffer substitute in calf diets: Effects on growth performance, rumen fermentation, and economics.
Strategic NaCl supplementation in calf diets can improve feed efficiency and reduce costs, but findings are specific to the study's conditions.
Where it sits
this study against the rest of the thymulin (facteur thymique serique) corpusSummary and findings
This study evaluated the effects of sodium chloride (NaCl) as a salivary stimulant and buffer substitute in calf diets on growth performance, rumen fermentation, and economics. Fifty Holstein calves were assigned to five treatment groups with varying NaCl levels and methods of provision. The T4 group, receiving twice the NRC-salt with 15% pre-fed, showed the most favorable feed conversion ratio and economic benefits.
Abstract
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.
Background
The study addresses the need for effective salivary stimulants and buffer substitutes in calf diets to enhance growth performance and rumen fermentation. Previous research has focused on chemical buffers, but there is interest in natural alternatives like sodium chloride. This study explores the potential of NaCl to improve feed efficiency and reduce costs in calf nutrition.
Methods
A completely randomized design was used with 50 Holstein calves, each weighing 46.43 ± 2.19 kg and aged 10 ± 5 days. Calves were assigned to five treatment groups: 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), and T5 (NRC-salt + 0.5% NaHCO₃ buffer). The primary outcomes measured included dry matter intake, feed conversion ratio, nutrient digestibility, saliva and rumen pH, and volatile fatty acid profiles.
Results
Treatments significantly affected dry matter intake, feed conversion ratio, nutrient digestibility, saliva and rumen pH, and volatile fatty acid profiles (P < 0.05). The T5 group showed the highest saliva volume and dry matter intake, while the T4 group had the highest saliva pH and the most favorable feed conversion ratio. Blood parameters were unaffected across treatments, and health indicators improved in all salt-supplemented groups.
Interpretation
The study suggests that strategic NaCl supplementation, particularly at twice the NRC level with a portion pre-fed, can enhance salivary buffering and feed efficiency in calves. The economic analysis indicates potential cost savings, making this approach a viable alternative to chemical buffers. However, the clinical significance of these findings is limited to the specific conditions and population studied, and broader applicability remains uncertain.
Key findings
- 50 Holstein calves, 46.43 ± 2.19 kg BW, 10 ± 5 days old
- Treatments significantly affected DMI, FCR, nutrient digestibility, saliva and rumen pH, and VFA profiles (P < 0.05)
- T5 promoted highest saliva volume and DMI
- T4 elicited highest saliva pH and most favorable FCR
- Economic savings of $5,593 annually for a 5,000-head herd with T4 strategy
Limitations
- Single species, Holstein calves only
- Limited to pre-weaned calves
- Short-term study duration
- Single-site study