Effects of seasonal variations on thermoregulation of ostrich

Twelve ostrich aged 7 months old were used during summer and winter from the breeding flock of the ostrich farm, at the Nuclear Research Center in Inshas, of Atomic Energy Authority, Egypt. In the study all birds were exposed to ambient temperatures in summer and winter, and the birds were fed grower ration ad libitum (19% protein and 2450 K cal ME /Kg).The present study was carried out to evaluate the effect of temperature variation during summer and winter seasons and diurnal effect on changes in some physiological and blood chemical parameters, the daily feed consumption (g/bird/day) and water consumption (ml/bird/day) these parameters were measured during 7 days in each season. Cloacal temperatures was measured and blood samples were taken twice, one in the morning at 7 am and once in the afternoon at 3 pm during a representative 7 hot days of June (40±2 degree C) (summer) and the 7 cold days of January (18±2 degree C) (winter). Red blood cell (RBCs) counts and total white blood cell (WBCs) counts, hemoglobin concentration (Hb) and packed cell volume (PCV) were determined. Mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular hemoglobin concentrations (MCHC) were calculated. Serum, total protein (TP), albumen (A) and globulin (G) concentrations were measured. Furthermore, serum alanine transaminase (ALT), aspartate transaminase (AST), glucose and triglycerides concentrations were determined. Also, serum triiodothyronine (T3), and aldosterone levels were estimated. Also, the amount of total body water was determined by the antipyren method. Finally, serum protein profile it was conducted by Native-PAGE method (Native polyacrylamide gel electrophoresis) on vertical slab gel to determine protein profiles in blood proteins of ostrich. Results indicated that feed consumption unlike water consumption was significantly increased during winter than in summer season. Moreover, body temperature increased significantly during the summer season as compared with the winter season and was significantly elevated at the afternoon than at the morning. Blood picture showed that haemoglobin concentration (Hb), packed cell volume (PCV), red blood cells (RBCs) counts and total white blood cell (WBCs) counts were significantly decreased in the summer than in winter months at the two diurnal periods. While both, mean corpuscular volume (MCV) and Mean corpuscular hemoglobin (MCH) were significantly increased in summer than winter season at the morning and afternoon periods. However, mean corpuscular hemoglobin concentrations (MCHC) was significantly decreased in summer season at morning only. In addition, at summer season, results showed that (Hb) concentration was significantly increased at the morning than afternoon while there were no significant differences in all of the other parameters. In addition, at winter season it was found that Hb concentration, PCV and both (RBCs) and (WBCs) counts were significantly elevated at morning as compared with at afternoon values. In the mean time, no significant differences between the morning and afternoon in MCV, MCH and MCHC measurements were observed.