Table 4.

Different strategies used in alleviating the effects of oxidative stress in poultry.

Strategies	Method	Mechanisms of action	References
Environmental approach
Controlled housing	Use of cooling equipment. E.g: fan, Ventilator, sprinkler system	Reduces the heat load on the body of the birds	Daghir, 2008
Management	Reduced stocking rate	Helps to reduce heat buildup and ammonia concentration in the pen	Saeed et al., 2018
Thermal conditioning	Embryonic thermal conditioning	Helps to inhibit the generation of uncoupled proteins and by increasing HSP70 synthesis thereby enhancing the bird's adaptive capacity	Oke et al., 2020; Liew et al., 2003, Loyau et al., 2016; Meteyake et al., 2020
Genetic approach
By using selected breeds of chicken	- naked neck genes	the reduced plumage helps in dissipating heat	Patra et al., 2002; Desta, 2021; Fernandes et al., 2023
	Frizzle gene	Helps to decrease feather intensity leading to an increase in the ability of the birds to dissipate heat -It also increases heat loss from the body	Fathi et al., 2019; Wasti et al., 2020,
Marker-assisted selected breeding	Use of candidate gene	of HSP90 and HSP70 gene expression helps to improve the thermotolerance of birds	Mahmoud et al., 2003
Dietary approach
Feeding method	Feed restriction	Restricting feed during high ambient temperatures helps to reduce thermal load caused by digestion	Syafwan et al., 2011
	Withdrawal of feed	It minimizes heat load accumulation caused by metabolic heat produced during the processes of digestion, absorption, assimilation, and excretion	Syafwan et al., 2011
	Wet feeding	Helps to promote water intake thereby relieving the birds from heat	Syafwan et al., 2011
Use of selected feedstuffs	Supplementation with fat and oil	Oils and fats contain high energy value which helps to promote feed consumption, reduces heat load, and improves performance	Attia et al., 2021
	Supplementation with dried plum	Dried plum helps to increase the HSP-related gene expression (HSP90, HSP70, HSF3, and HSF1) and antioxidant-related genes (GPX, GPX, and SOD)	Wasti et al., 2021
	Amino acids	Supply of essential amino acids like lysine and arginine is advantageous to minimize the impacts of heat stress. Also, supplementation with Methionine reduced muscle oxidation and improve antioxidant status in thermally-challenged chickens Sulfur amino acids supplementation also helps in reducing chronic heat stress by increasing antioxidant production and also protects the intestinal permeability of broiler chickens	Saeed et al., 2018; Zeitz et al., 2020; Ajayi et al.; 2022; Sarsour et al., 2022
	Use of non-limiting amino acids and their derivatives (betaine taurine, L-citrulline and L-theanine,)	They have bioactive compounds that have properties that make them act as antioxidants, immunomodulators, anti-stressors, gut stimulants and anti-inflammatory when fed to heat-stressed birds	Uyanga et al., 2022
	Vitamins	Vitamins A, B, D, E, and C are involved in upregulating immunocompetence and antioxidant defense in heat- stressed broilers	Niu et al., 2009; Khna et al., 2011; Calik et al., 2022
	Minerals	Offering potassium chloride to heat-stressed birds reduced the blood pH there by enhancing the thermotolerance of the birds. Zinc is a cofactor for several enzymes and its addition to feed brings about a decrease in plasma corticosterone levels Selenium helped to increase the heat resistance of heat-stressed birds Manganese helps to increase the secretion of heat shock protein and also promotes antioxidants expression Chromium helps to improve oxidative stability and blood biochemical indices	Ahmad et al., 2008; Toghyani et al 2012; Khan et al., 2014; Habibian et al 2015
Phytogenics	Resveratrol, ginkgo, cinnamon, licorice, moringa, rosemary, thyme, hot red pepper, sweet wormwood, turmeric, black cumin and ginger	Bioactive agents including quercetin resveratrol, and curcumin have been shown to activate vitagenes which helps to regulate the antioxidant defense system effectively. They help in scavenging free radicals, enhancing the immune system, decreasing corticosterone release, controlling heat shock response, improving nutrient digestibility, protecting intestinal health, exerting antimicrobial effects, decreasing lipid peroxidation, promoting the antioxidant defense system and regulating blood biochemical properties. It should be noted that the phytogenic active compounds for example, polyphenols may contain anti-nutritional factors or may be poorly absorbed and in some cases may not be detected in target tissues.	Nawab et al., 2018, 2019; Madkour et al., 2022; Oyelola et al., 2024; Ding et al., 2023, Akosile et al., 2023b; Kpomasse et al., 2023b; Oke et al., 2017 ; Onagbesan et al., 2023; Tokofai et al., 2023; Oke, 2018; Oke et al., 2021b