Table 2. Showing the beneficial effect of microalgae on poultry birds

Type of animal	Type, dosage and duration	Mechanism	Overall effect	References
Broilers and layers	Spirulina (1.5%, 3.0%, 6.0%, or 12.0% for nine weeks	↑ Cellular and humoral immunity,↑ Maintaining the beneficial intestinal bacteria↓ Pathogenic bacteria↑ Improving the carcass traits	Improves productive performance of broilers and layers	El-Ghany (2020)
Broilers	1%–2% micro algae in diet for 42 days	↑ Superoxide dismutase (SOD)↓ Polyunsaturated fatty acid↓ Malondialdehyd	Improves performance, serum composition, carcass trait, antioxidant status, and fatty acid	El-Bahr et al. (2020)
Broilers	Microalgae Chlorella spp. 0.5%–1.0% of the diet	↑ Blood total protein, albumin↑ High-density lipoprotein (HDL) cholesterol↓ Alanine aminotransferase and ALT↑ Blood lymphocytes↑ IgA, IgG, and IgM	↑ Body weight gain↓ Feed conversion ratio↓ Drip loss↑ Liver function↑ Immunity	Abdelnour et al. (2019)
Cornish cross chicks	Docosahexaenoic acid (DHA; 22:6n-3)-rich 2% microalgae for day 42	↑ Breast muscle↑ Meat tenderness and color↓ Incidence of breast muscle striping and myopathy	Improves production performance, breast muscle quality attributes, lipid profile, and incidence of white striping and myopathy	Khan et al. (2021)
Isa brown laying hens	DHA-rich microalga 0.25%, 0.5%, and 1.0% for 40 d	↑ Nutrititive value of hen’s eggs	↑ Omega-3 content of eggs	Moran et al (2018); Moran et al. (2019)
Broiler chickens	Microalgae Tetraselmis chuii 20 g/kg of feed (2%)	↓ S. Infantis caecal load	Antibacterial	Corrales-Martinez et al. (2022)
Broiler chickens	Microalgal DHA 2% for 6 weeks	↑ Body weight gain↓ Cholesterol and triglyceride concentrations in plasma, liver, breast, and thigh↑ Improve tibia breaking strength↑ Total bone volume and bone mineral	Improves growth performance, tissue lipid profiles, and tibia characteristics	Kalia et al. (2023)
Fayoumi broilers	Microalgae (Spirulina platensis) 1% for 8 weeks	↑ Serum total protein↑ Globulin↓ Serum cholesterol↑ Lymphocyte percentage	Improves growth performance, ingestive behavior, hemato-biochemical parameters, and economic efficiency	Hassan et al. (2022a)
Broiler and layer birds	Microalgae	↑ Weight, Feed intake and digestibility↑ Increase meat quality↑ Improve organoleptic quality of meat↑ Digestibility↑ Egg shell thickness and egg weight	Enhances the nutritive value of poultry meat an eggs	Esakkimuthu et al. (2024)
Broiler and layer birds	S. platensis (0.25%–1.0%) and Chlorella vulgaris (1.55 g/kg)	↓ Oxidative stress↑ Immune response, growth rates, feed conversion ratios↑ Carcass quality, and meat attributes↑ Egg production and egg quality	Positive impact on performance metrics	Abdel-Wareth et al. (2024)
Broiler	S. platensis (10%) and Haematococcus pluvialis (0.004%)	↑ GSH, glutathione peroxidase (GPx) and SOD	Improves antioxidant status	Abdel-Wareth et al. (2024); Jubie et al. (2012)
Broilers	C. vulgaris spp.; CLV; 0.5%–1.0% of the diet)	↑ Body weight gain (2.7%)↑ Feed conversion ratio (lowered by 2.8%)↑ Meat color and breast muscle weight (20.1%)↓ Drip loss (2.26%) from breast muscle↑ IgA (29.7%,), IgG (69.1%), and IgM (32.3%)	Improves growth and health of birds	Abdelnour et al. (2019)
Ross-308 broiler chicks	1 g/kg diet of C. vulgaris (CV), S. platensis, and Amphora coffeaformis (AC)	↑ Essential fatty and amino acids↓ Microbial growth in breast muscle↓ Malondialdehyde (MDA) and protein carbonyl (PC) levels, cooking loss and aerobic plate count (APC)↑ SOD activities in breast muscle	Enhance performance and meat quality in broiler chickens	El-Bahr et al. (2020)