Effect of dietary curcumin on the antioxidant status of laying hens under high- temperature condition.

Heat stress induces oxidative stress, and reduces antioxidant defenses of birds, which may affect poultry-production performance. Dietary antioxidants may protect against heat stress. We evaluated the effect of increasing concentrations of dietary curcumin on antioxidant parameters of hens under high-temperature conditions for nine weeks. Roman laying hens (n = 336, 22 weeks old, 1420 g weight) were divided into three treatment groups. The first group served as a thermo-neutral control (kept at 25 ±â€¯1 °C). The second group was exposed to high temperatures (32 ±â€¯1 °C, 6 h/day), and fed a basal diet. The third group was further divided into five groups, and all were exposed to high temperatures (32 ±â€¯1 °C, 6 h/day) and provided a basal diet supplemented with 100, 150, 200, 250, 300 mg/kg curcumin (H1, H2, H3, H4, H5). All treatments included four replicates of 12 hens. Total superoxide dismutase (SOD) activity was significantly higher in H2 and H3 groups, and total antioxidant capacity (T-AOC) was higher in H2, H3, and H5 groups. Catalase (CAT) and glutathione peroxidase (GSH-Px) activities were significantly higher in the H3 group. Malondialdehyde concentrations were lower in curcumin supplemented hens compared to control groups hens. Hens in all curcumin treatment groups had slightly (but non-significantly) higher activities of CAT, SOD, GSH-Px, and T-AOC in liver, heart, and lung tissues, compared to heat stressed control group. It is concluded that dietary curcumin given to laying hens under heat stress may enhance their antioxidant status, and ameliorate stressful environmental conditions.

Heat stress in poultry production: Mitigation strategies to overcome the future challenges facing the global poultry industry.

Worldwide, the effect of climatic variations has become a great challenge in poultry production. As global climate is changing, it alters the environmental temperatures, precipitation patterns and atmospheric carbon dioxide. Poultry farming mainly depends on climatic conditions such as temperature and humidity. Several factors can be involved but heat stress is one of most important environmental factor influencing a wide range of chickens performances including reduced feed intake which, in turn, affects growth rate, body weight, meat quality, egg quality, egg production, semen quality and fertility; these negative influences result in great economic losses. Heat stress associated food safety issues have gained special importance due to public awareness and an abundance of available scientific information. Environmental modifications (early heat conditioning, open sheds and cooling systems) and nutritional strategies (early feed restriction, electrolyte, vitamin and mineral balance) cannot satisfy the special needs of stressed poultry. Therefore, there exists a crucial need to explore effective strategies including genetic markers to enhance thermo-tolerance and productivity of poultry birds in hot regions of the world.