11/01/2026
Cysteamine (CS) is a bioactive compound that can be administered orally or intravenously and it has demonstrated the capacity to enhance production performance in various livestock species. CS is also synthetically available as a dietary additive in the form of cysteamine hydrochloride (CSH). It is a stable amino-thiol compound and one of the metabolic enhancers and activity modifiers in living tissue. A neuropeptide called βsomatostatinβ is extensively present in the digestive tracts of animals. Somatostatin has an inhibitory effect on growth hormones, metabolic hormones, and digestive enzyme secretion from the pancreas and small intestine and also an immunosuppressive effect by decreasing the IgA-positive cells in the duodenal and jejunal mucosa. Dietary inclusion of CSH exerts an inhibitory effect on somatostatin while increasing the production of growth hormone, which increases the production of insulin-like growth factor, which ultimately may enhance the BWG of broilers. Derivatives of CSH are also reported to promote animal growth by lowering oxidative stress, maintaining intestinal integrity, and enhancing immunity. CSH mediated increases in growth hormone secretion and enhances B-cell development, and antibody production from the immune system. Through three distinct mechanisms, CSH functions as an antioxidant: (i) its thiol group acts as an antioxidant; (ii) it raises glutathione (GSH) levels in cells; (iii) it eliminates hydrogen peroxide and can also directly eliminate reactive oxygen species (ROS) and harmful byproducts of lipid peroxidation. The increases in the concentrations of metabolic hormones, thyroxine (T4), and triiodothyronine (T3) have been ascribed to the application of CSH. Moreover, the secretions of pancreatic proteases, lipase, and amylase are also attributed to CSH, which leads to improved digestion of proteins, fats, and carbohydrates, respectively.