Investigations on modulating effect of three tropical red seaweed by-products on growth performance, immune response, antioxidant status and endocrine variables in crossbred calves

We evaluated the effects of the inclusion of Kappaphycus alvarezii (KA), Gracilaria salicornia (GS) and Eucheuma spinosum (ES) as feed additives on the growth, immune and antioxidant status, endocrine variables, nutrient utilization, and nitrogen balance in growing Karan fries calves. Twenty-four growing crossbred calves (body weight 104.00 +/- 2.0 kg) were randomly blocked into four groups, each comprising six animals. The feeding schedule was similar in all the groups except that the treatment groups were supplemented with red seaweed (KA, GS, and ES) at 2.5% of dietary concentrate mixture during 180 days of the trial. No significant difference (p > 0.05) was noticed in body weight, average daily gain, dry matter intake and feed conversion ratio among the groups. Nutrient digestibility and nitrogen balance remained unaffected. There was no effect (p > 0.05) on haemato-biochemical parameters due to red seaweed supplementation. The levels of superoxide dismutase (SOD), catalase (CAT) and serum GSH-Px were similar in all the treatment groups. The addition of seaweeds did not exert any effect on mean serum levels of triiodothyronine (T-3), thyroxine (T-4) and cortisol. The serum concentration of immunoglobulin (IgG) was significantly higher among the seaweed-supplemented groups than the control group. Conclusively, the dietary supplementation of tropical red seaweeds at 2.5% in the concentrate mixture may significantly influence immunity without any alteration in hormonal profile, antioxidant status, serum metabolites, enzymes, and performance of growing crossbred calves.