Supplementation of corn seed with regular diet modulates immune function and antioxidant status in Capra hircus
The phytomelatonin was first identified in coffee beans in 1970 (Tan et al., 2011), and later, different plant species like cereals and medicinal herbs have also been reported to contain high melatonin concentration (Hattori et al., 1995; Hardeland and Pandi‐Perumal, 2005). Phytomelatonin regulates different physiological functions in plants, such as morphogenesis, photoprotectant and stress responses (Arnao, 2014). Phytomelatonin supplementation has been reported to increase the endogenous melatonin concentration (Oba et al., 2008). However, there is no report that could suggest the effect of melatonin supplementation from plant source on cellular‐immune function and antioxidant status of any small ruminant species like goat. Goats are important livestock for the raisers in the developing countries like India. These animals confront extreme environmental stress conditions due to their browsing and grazing activity that leads to their high mortality and huge economic loss to the raisers. Thus, preventive measures are needed for the improvement of their health by non‐invasive approaches.
Therefore, in the present study, we hypothesized that the supplementation of corn seed (Zea mays) with regular diet might increase the endogenous melatonin concentration that may modulate cell‐mediated immune functions and antioxidative enzymes activity in goat, Capra hircus. Corn seeds (Z. mays), a common primary cereal that contains high melatonin level (1366 pg of melatonin/g of corn seeds; Hattori et al., 1995; Hardeland and Pandi‐Perumal, 2005), were selected for the supplementation with regular diet as source of exogenous melatonin to the goats. The general immune parameters such as total leucocyte count (TLC), %lymphocyte count (%LC), proliferative response of the peripheral blood mononuclear cells (PBMCs) in terms of % stimulation ratio (%SR) along with levels of cytokines (IL‐2, IL‐6, TNF‐α) and melatonin concentration were noted after feeding maize for 40 days. The activity of antioxidative enzymes like, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH‐Px) along with levels of malondialdehyde (MDA) and total nitrate and nitrite ion concentration and total antioxidant status (TAS) was estimated in goat plasma.