Abstract

Background:
Heat stress is a major challenge affecting goat production in arid and semi-arid regions, causing oxidative stress and immunosuppression. This study investigated the effects of Moringa oleifera leaf extract (MOLE) and turmeric (Curcuma longa) supplementation on immune parameters and antioxidant enzyme activities in shami (Damascus) goats under heat stress conditions.

Aim:
To evaluate the effects of turmeric and Moringa oleifera leaf extract supplementation on the immunological and antioxidant responses of heat-stressed shami goats.

Methods:
Twenty-four adult Shami goats (2–3 years, 35 ± 3 kg) were randomly allocated to four groups (n = 6): control (CON), MOLE-supplemented [monocytes (MO), 3% of dry matter intake], turmeric-supplemented [total urinary ratio (TUR), 2% of daily mean intake], and combined supplementation (MO + TUR). The experiment lasted 60 days during summer (Temperature–Humidity Index: 82–92). Blood samples were collected biweekly for analysis of antioxidant enzymes Superoxide dismutase [SOD, catalase (CAT), and glutathione peroxidase (GPx)], proinflammatory cytokines (IL-6, TNF-α), lymphocyte subpopulations (CD4+ and CD8+), immunoglobulins (IgG and IgM), and heat shock proteins (HSP70 and HSP90).

Results:
Combined supplementation (MO+TUR) significantly increased SOD (93.40 ± 2.1 U/ml), CAT (55.03 ± 1.8 U/ml), and GPx (15.03 ± 0.5 U/ml) activities compared to control (p < 0.001). IL-6 levels decreased from 45.3 ± 3.2 pg/ml CON to 22.1 ± 1.9 pg/ml (MO+TUR), while TNF-α reduced from 38.7 ± 2.8 to 18.4 ± 1.7 pg/ml (p < 0.001). CD4+/CD8+ ratio improved from 1.2 ± 0.1 (CON) to 1.8 ± 0.1 (MO+TUR). HSP70 expression increased 2.3-fold in supplemented groups. IgG concentrations elevated from 12.3 ± 0.8 to 16.8 ± 0.9 mg/ml (p < 0.05).

Conclusion:
Combined M. oleifera and turmeric supplementation effectively mitigated the effects of heat stress by enhancing antioxidant defense systems, modulating inflammatory responses, and improving cellular and humoral immunity in shami goats. This natural intervention strategy presents a sustainable approach for maintaining goat health and productivity under heat stress conditions.

Key words: Curcumin; Cytokines; Damascus goats; Heat stress; Moringa oleifera.