Abstract
Background and Aim: Free-range laying hens raised under tropical climates are susceptible to heat stress (HS), which compromises intestinal integrity, nutrient absorption, and egg quality. Ganoderma lucidum (Lingzhi) contains potent antioxidant compounds, but its efficacy in animal diets is limited by poor solubility and stability. This study evaluated the effects of dietary microencapsulated G. lucidum extract (MGE) on laying performance, antioxidant capacity, intestinal morphology, and nutrient digestibility in free-range hens under high-temperature conditions.
Materials and Methods: A total of 256 Hy-Line Brown hens (25 weeks old) were randomly assigned to four dietary treatments with four replicates of 16 birds each: (i) basal diet (control [Con]), (ii) basal diet + free G. lucidum extract (1, 000 mg/kg), (iii) MGE at 1, 000 mg/kg (MGE0.1), and (iv) MGE at 500 mg/kg (MGE0.05). The trial lasted 12 weeks under natural tropical temperatures. Productive performance, egg quality, fatty acid profile, jejunal histomorphology, and antioxidant indices were analyzed. Statistical analysis was conducted using one-way analysis of variance with Tukey’s test (p ≤ 0.05).
Results: MGE supplementation improved average egg weight and albumen height without affecting feed intake or feed conversion ratio. Both MGE0.1 and MGE0.05 increased jejunal villus height, width, surface area, and the villus height-to-crypt depth ratio compared with the Con. group. MGE diets significantly increased apparent ileal digestibility of dry matter, crude protein, gross energy, and ash. Enhanced antioxidant responses were observed, including higher total antioxidant capacity (15%–19%), superoxide dismutase (15%–22%), and catalase activity, with a concurrent 46%–47% reduction in malondialdehyde. Additionally, MGE diets reduced yolk cholesterol and the n-6/n-3 polyunsaturated fatty acid ratio.
Conclusion: MGE effectively enhances intestinal morphology, antioxidant defense, and nutrient utilization in free-range hens exposed to HS, thereby improving egg quality and the yolk lipid profile. MGE represents a promising natural antioxidant and feed additive for sustainable poultry production under tropical conditions.
Keywords: antioxidant capacity, Ganoderma lucidum, intestinal morphology, laying hens, microencapsulation, nutrient digestibility, tropical heat stress.