Date of Graduation


Document Type


Degree Name

Master of Science in Poultry Science (MS)

Degree Level



Poultry Science


Sara K. Orlowski

Committee Member

Michael T. Kidd

Second Committee Member

Walter G. Bottje


Algae, Heat stress, Spirulina platensis


The effect of Spirulina platensis inclusion in feed of commercial broilers was evaluated over one experiment. The study aimed to investigate the effects of Spirulina platensis freshwater algae inclusion on live performance and processing characteristics of commercial broilers subjected to daily cyclic heat stress. Day old Ross 708 male broilers were placed into 8 environmentally controlled chambers. At d 21, four chambers remained on a control diet containing no algae (CON) while 4 chambers received a diet that included algae at an inclusion rate of 2.5% (ALG). An 8 hour daily cyclic heat stress (24°C to 36°C) was applied to the chambers from d 22 to processing at d 48. Twenty-one broilers were sampled for breast tissue on d 45. The remaining broilers were processed at d 48 and meat quality attributes were assessed. No differences were observed for feed conversion ratio, water conversion ratio or live weight throughout the grow-out period. Additionally, mortality did not differ between the treatments (ALG=5.8%, CON=3%). From sampling there was no significant difference between ALG and CON birds for SOD1, SOD2, GPx, HSP70 and HSP90 regulation. At processing, no differences were observed between the groups for carcass weight, wing, breast, tender, or leg quarter yield, breast pH, breast L* or drip loss. The ALG birds had a higher a* value and b* value than CON birds. It appears that inclusion of freshwater algae at a level of 2.5% did not have an impact on live performance, processing parameters or meat quality of commercial broilers subjected to cyclic heat stress. Higher levels of algae inclusion need to be evaluated.