Effects of Morinda citrifolia (Noni) pulp on growth performance and stress responses of growing cattle1

The pulp of Morinda citrifolia (Noni), a Tahitian plant known to reduce stress and improve immunity in laboratory rats, was fed to growing cattle. Thirty crossbred beef calves (262 kg) were limit fed diets that were top-dressed with 0, 0.09, or 0.18% Noni pulp (DM basis) for 28 d. Every 4 d, cattle were weighed, bled, and assessed for subjective and objective excitability measures. Average daily gain increased linearly (P = 0.03) as the percentage of Noni increased in the diet. Noni-supplemented cattle gained more efficiently, as the G:F increased linearly (P = 0.04) with increasing Noni addition. Additionally, Noni-fed cattle had decreasing concentration of white blood cells with increased Noni supplementation (linear; P = 0.001). However, control cattle had similar serum cortisol concentrations to those fed Noni pulp (P = 0.16), and neither exit velocity nor subjective pen and chute excitability scores were affected (P ≥ 0.79) by the addition of Noni to the diet. Therefore, Noni has the potential to improve growth and health in weaned, growing cattle, but the mechanism of action of Noni in cattle is not known.