Date of Graduation


Document Type


Degree Name

Bachelor of Science in Agricultural, Food and Life Sciences

Degree Level



Poultry Science


Erf, Gisela

Committee Member/Reader

Orlowski, Sara

Committee Member/Second Reader

Rochell, Samuel


Immune system health is an important aspect of broiler production, especially with the reduction of the use of antibiotics. Nutritional aspects, like crude protein percentage, and natural alternatives to antibiotics are being investigated to see the effect they have on immunity. Spirulina is an alternative proteinaceous ingredient that producers are looking into, not only due to its high nutritional value, but also its immune boosting properties. The purpose of this study was to determine the effects of a low crude protein diet (LCP) and a Spirulina-supplemented low crude protein (LCP-SP) diet on broiler blood cell measurements, including, concentrations and proportions of individual white blood cell populations and various lymphocyte subsets. Ross 708 1-day old male broilers were assigned to one of three diet treatments: a standard crude protein diet (SCP), the LCP diet, and the LCP-SP diet, with 5 pens per dietary treatment. When the chickens were 37 days of age, heparinized blood samples were used to determine the concentrations of white bloods cells (WBC), thrombocytes, red blood cells (RBC), hemoglobin, and hematocrit by Cell-Dyn automated hematology analysis, prepare and Wright-stain blood smears for leukocyte counting by microscopy, and conduct immunofluorescent staining of peripheral blood mononuclear cells for lymphocytes population analysis by flow cytometry. Except for monocytes, none of the blood cell measurements conducted were affected (P > 0.05) by diet. The LCP diet resulted in increased (P ≤ 0.05) monocyte concentration and proportion (% of WBC) compared to the standard CP diet, indicating heightened inflammatory activity with lower dietary protein content. The LCP-SP reversed the effect of the LCP diet, resulting in monocyte concentrations and proportions not different (P > 0.05) from those of the SCP diet. Natural feed additives can reverse the effects that low crude protein has on immunity in broilers, which is a promising sign for lowering feed costs without impacting the health of the bird.


leukocytes, lymphocytes