Abstract
The intent of the study was to investigate the effect of dietary inclusion of sodium bicarbonate (NaHCO3) on blood profile of
caged layers during summer. One hundred sixty commercial layers were divided into 20 experimental units/replicates (8
layers/replicate), which were further allotted to five treatment groups (4 replicate/treatment). Five iso-nitrogenous (CP 17%)
and iso-caloric (ME 2700 Kcal/Kg) diets (A, B, C, D and E) were prepared with or without addition of NaHCO3. Diet A, was
without NaHCO3 and served as control whereas, diets B, C, D and E contained 0.5, 1.0, 1.5 and 2.0% NaHCO3, respectively. These diets were fed to the experimental birds from 26
th - 37
th weeks of age (12 weeks). At the end of the experiment, blood
samples of two birds from each replicate were collected for the analysis of blood profile. Results of the study revealed that
serum glucose, white blood cells count, serum urea, plasma chlorides, serum cortisol and serum glutamic-oxaloacetic
transaminase concentrations were found to be significantly (P<0.05) higher in control group, whereas, blood hemoglobin
concentration, red blood cells count, plasma sodium, potassium, bicarbonate, serum total protein and serum albumen
concentrations were significantly (P<0.05) higher in the birds fed diet containing 1% NaHCO3. Whilst, Serum uric acid
concentration was significantly (P<0.05) higher in those fed 2% NaHCO3.However, packed cell volume, erythrocyte
sedimentation rate, serum creatinine, alkaline phosphatase, plasma calcium,plasma phosphorus, serum globulin and serum
glutamic pyruvate transaminase concentrations were not affected due to the dietary treatments. Serum cholesterol, triglycerides and low density lipoprotein concentration were significantly (P<0.05) decreased, whereas, serum high density
lipoprotein concentration was found to be significantly (P<0.05) increased by dietary inclusion of NaHCO3. Birds fed diet
containing 1% NaHCO3 showed significantly (P<0.05) higher concentration of estrogen, progesterone, T3 and T4 hormones. It was concluded that being economical and easy to handle, dietary inclusion of NaHCO3 may be a better choice to reduce or
at least ameliorate the harmful effects of heat stress on blood chemistry in caged layers reared in summer conditions.