# Effects of Sodium Butyrate and Organic Zinc Supplementation on Performance, Mineral Metabolism, and Intestinal Health of Dairy Calves

## TL;DR

This study found that adding sodium butyrate and organic zinc to dairy calves' diets had limited benefits on growth and health despite improving zinc absorption.

## Contribution

The study provides new insights into the limited efficacy of sodium butyrate and organic zinc in improving calf health under high stress conditions.

## Key findings

- Supplementation increased zinc absorption and retention but did not reduce diarrhea incidence.
- Additives had limited effects on calf growth or health under high environmental and sanitary challenges.
- Organic zinc tended to increase serum zinc concentrations compared to the control group.

## Abstract

The rearing phase is a challenging period in dairy farming. It involves environmental, health, and physiological stressors that can affect calf growth and well-being. Nutritional strategies such as sodium butyrate and organic zinc supplementation have been proposed to mitigate these effects. Therefore, this study evaluated the effects of sodium butyrate and organic zinc supplementation, alone or in combination, on the performance, zinc balance, intestinal health, and oxidative stress markers of dairy calves under heat stress and high sanitary challenge. Forty-eight male calves were assigned to one of four groups: control group, group supplemented with sodium butyrate, group supplemented with organic zinc, and group supplemented with both. Calves were monitored for feed intake, weight gain, body measurements, and fecal score. Zinc absorption was also evaluated, and some calves were slaughtered to assess intestinal permeability. The incidence of diarrhea was high in all groups, and supplementation with sodium butyrate and/or organic zinc did not reduce its occurrence. There were significant increases in Zn absorption and retention. However, the additives, whether given alone or together, had limited effects and did not improve calf growth or health under high environmental and sanitary challenges.

The objective of this study was to evaluate the effects of sodium butyrate and organic zinc supplementation, alone or combined, on performance, zinc metabolism, blood parameters, and gut health in Holstein calves highly challenged by heat and diarrhea during the pre-weaning and weaning periods. Forty-eight male calves were assigned to one of four treatments: control (CON), SB (3 g/kg of sodium butyrate in dry matter [DM]), OZn (262 mg/kg of organic zinc in DM), or SBOZn (3 g/kg of sodium butyrate and 262 mg/kg of organic zinc in DM). Calves were monitored from days 7 to 63 for feed intake, weight gain, body morphometry, fecal score, and blood parameters. Zinc balance was evaluated from days 45 to 49, and 24 calves were slaughtered on day 64 for jejunal sampling to assess tight junction gene expression. Diarrhea incidence was high (>90%) across groups. Fecal scores varied over time but did not differ between treatments. The OZn and SBOZn groups had higher Zn intake, with greater absorption and retention of the mineral compared to the CON and SB groups. Additionally, the OZn group tended to have higher serum Zn concentrations. SB and OZn, separately or combined, had limited effects and did not consistently improve the performance or health of calves highly challenged during pre-weaning and weaning.