# Enhancement of growth performance and health status in heat-stressed growing rabbits using alpha-lipoic acid-loaded chitosan nanoparticles

## TL;DR

This study shows that adding alpha-lipoic acid-loaded chitosan nanoparticles to rabbit diets improves growth and health under heat stress.

## Contribution

The novel use of alpha-lipoic acid-loaded chitosan nanoparticles to mitigate heat stress in rabbits is presented.

## Key findings

- ALA-CHNPs improved growth performance, feed conversion, and liver health in heat-stressed rabbits.
- Optimal benefits occurred at 250–300 mg/kg diet, reducing oxidative stress and inflammation.
- ALA-CHNPs restored hepatic morphology and reduced heat stress-induced liver damage.

## Abstract

This study investigates the effect of alpha-lipoic acid-loaded chitosan nanoparticles (ALA-CHNPs) on growth performance, feed utilization, and health in heat-stressed growing rabbits.

A total of 125 healthy, 5-week-old rabbits were randomly assigned to five groups of 25. One group served as a thermoneutral control, while the other four groups were subjected to heat stress and received diets supplemented with 0, 100, 200, or 400 mg of ALA-CHNPs per kilogram, respectively.

Dietary supplementation resulted in significant improvements in growth performance, feed conversion ratio, physiological responses, liver weight, and dressing percentage. Supplementation with ALA-CHNPs resulted in a linear reduction in liver enzymes activities, as well as in the levels of total bilirubin, hydrogen peroxide, glutathione, catalase, superoxide dismutase, immunoglobulin G, lysozyme activity, interleukin (IL)-6 and IL-10. No significant differences were observed between the ALA-CHNPs200 and ALA-CHNPs400 groups (p>0.05). The levels of blood serum total protein, albumin, globulin, total antioxidant capacity, glutathione peroxidase activity, immunoglobulin A and M, and nitric oxide showed a quadratic increase, reaching a peak at ALA-CHNPs doses ranging from 250–300 mg/kg diet. Conversely, the concentrations of triglycerides, cholesterol, glucose, malondialdehyde, interferon-gamma, tumor necrosis factor-alpha, and nuclear factor kappa B exhibited a quadratic decrease, with optimal reductions observed at doses between 250–300 mg/kg diet. Supplementation with ALA-CHNPs reduced liver damage caused by heat stress, restoring normal hepatic morphology. The hydrophobic interactions of ALA with antioxidant enzymes and cytokines contributed to the reduction of heat stress-induced oxidative stress.

The inclusion of 250–300 mg ALA-CHNPs/kg diet enhanced growth performance, redox balance, immune function, and inflammatory response in fattened rabbits raised during the summer season.